Corbin Handbook
of
Bullet Swaging
No. 9
by
David R. Corbin
Corbin Manufacturing & Supply, Inc.
PO Box 2659
White City, OR 97503 USA
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Corbin Handbook of Bullet Swaging No. 9
by
David R. Corbin
Corbin Manufacturing & Supply, Inc. PO Box 2659 White City, OR 97503 USA
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Corbin Handbook of Bullet Swaging, No. 9
© Copyright 2004 David R. Corbin
All rights reserved. May not be reproduced by any means, including electronic and mechanical, without the expressed written permission of the copyright holder.
Published by:
Corbin Manufacturing & Supply, Inc. PO Box 2659 White City, OR 97503 USA
541-826-5211 Mon-Thurs 9am-5pm
Fax: 541-826-8669 24/7
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1. Introduction to Bullet SwagingGood morning! I'm Dave Corbin, and for over 30 years I've had the second best job in the world: I help people make the state-of-the art bullets that you've read about in the gun magazines. Nearly every custom bullet maker started with equipment developed at the Corbin die-works. They have the best job in the world! All you have to do is scan the pages of nearly any magazine catering to handloaders, and you'll see dozens of ads from our clients; the articles are constantly talking about the bullets our clients make, and the major ammunition firms are buying the bullets made on Corbin equipment for use in their premium ammo. There has been a lot more research and development that you don't read about, because it isn't intended for the general shooting public. I can now include a small amount of that information in this edition. Corbin Manufacturing publishes a book called the "World Directory of Custom Bullet Makers" listing hundreds of individuals and firms whose names you may recognize if you are familiar with handloading. When I read the list, I remember someone's enthusiasm for the new business venture they were able to start, thanks to the power of bullet swaging. Olympians and world champions in every field of firearms sports, from benchrest to air gun competition, using everything from paper-patched blackpowder bullets to custom fin-stabilized shotgun slugs, have come to the die-works where we have toiled for the last quarter century and into the first quarter of this one, some just to improve their already-outstanding achievements, and some to help others become better shooters by manufacturing new ideas in how a given bullet should look and be constructed. Engineers from the Department of the Army, Air Force Armament Labs, Sandia National Laboratories, DuPont, Northrop, Lockheed, Martin-Marietta and other defense-related organizations have visited us over those years, sometimes sketching ideas on napkins during lunch. Tools and designs we worked on are in use today all over the world, wherever a long range, high precision projectile or a very special purpose bullet that could only be made efficiently by the high precision techniques of swaging, is needed for the job. Whether it is protecting an important public figure at long range or picking a pine cone from the top of an experimental tree, whether it is surveying a dense mountain jungle with remotely launched flare projectiles designed for vertical firing stability, or stitching mirror-based bullets in an arctic ice sheet from a low-flying aircraft so a laser beam can measure the depth and estimate the strength of the ice to hold a transport plane, or whether it is the grim responsibility of instantly stopping a terrorist before he can take the life of another hostage—regardless of the purpose, we sat through many meetings pouring over blueprints, computer readouts, and sketches, helping design projectiles for visitors from the far corners of the earth. | |||
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Yet, this work is only the continuation of development begun by other pioneers of bullet swaging: people like Ted Smith, who founded the old SAS Dies in the 1950's; Harvey Donaldson, who experimented with some of the first dies to make .224 bullets from fired .22 cases; Walt Astles and Ray Biehler, who developed the principle of upward expansion and the two-die swage technique which replaced the RCBS single-die take-apart system; Charlie Heckman, a pioneer swage maker; and so many others whose names are probably unknown to modern shooters, but to whom all shooters owe a debt for their contributions to the perfection of bullets. You may know that the RCBS company (initials of which mean Rock Chuck Bullet Swage) got started making bullet swaging equipment, but soon dropped it in favor of more easily produced reloading dies. You may even have heard Speer Bullets was started by Vernon Speer swaging .224 caliber bullets from fired .22 LR cases. But bullet swaging played a much larger part than just that, in leading to the products and companies you use today: Hornady, Sierra, Nosler, Barnes, Swift and a host of other mass production operations owe their very existence to the concept of bullet swaging. Today, more than four hundred custom bullet firms—operated by people who probably differ from yourself only in having taken the step of putting their intense interest in firearms to work at a profitable and enjoyable occupation—produce specialty bullets. We call this field "custom bullet making", the elite corps of bullet manufacturing providing initial concept advances sometimes copied years later by the larger "mass production" bullet makers. So, what is bullet swaging and how do you do it? What do you need to get started? How much does it cost? What are the advantages and drawbacks compared to casting or just buying factory bullets? Can you swage hard lead, make partitioned bullets, make your own jackets, make plain lead bullets or paper patched slugs? I answer those questions a thousand times a week and I never get tired of it. But to save you a lot of time on the phone, I've written most of those answers here. If you read through this book and think I have left something out, you are absolutely right: I left out about seven more books of information! Those are available if you care to read further. Swaging is so simple you can do it correctly after just a couple of tries. Then you'll see it's also extremely versatile and powerful: you can do one more thing, and then one more after that, and soon you will have the whole top of your loading bench covered with one-of-a-kind bullets, some of which no one in the world has ever made before. That's why it takes at least seven more books to make a dent in the vast array of things you might do, could do, if you wished. Only your imagination limits the possibilities. A deeper study of the specifics of bullet swaging technique and tooling, including products made by people other than Corbin, can be found in the book "Re-Discover Swaging", so named because swaging was, in fact, discovered once before and then almost lost: during the period of 19481963 there were many die-mak | |||
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ers who produced swaging equipment, but none of them offered a comprehensive enough range of products to insure their own survival, or that of the swaging arts. Corbin Manufacturing was the first comprehensive effort to preserve and further the technology with information, supplies and tools from one source. Whereas other die-makers tended to be secretive and often died with their secrets of bullet making, Corbin began publishing information that would help advance the field, from our beginning days. Bullet swaging, by the way, is pronounced "SWAY-JING" and rhymes with "paging". There is a blacksmith technique for pounding hot metal around a form that is called "swedging" but it is a different sort of thing altogether. If you want to really dig into the subject and learn things most people never discover, then order the Book Package. You get another copy of this book free, with it. Give this copy to a friend. Who knows: maybe between the two of you, a new bullet making business may develop that rivals the fame of some of our other clients? It could happen: it has happened over 400 times so far!
Warning! While the majority of handloaders say that they enjoy reading the additional side trips that clutter my books, some have complained that I don't get "to the point" and just tell them 1-2-3 how to make a bullet. I agree that this would be a good idea, if only I had some way to know exactly which bullet they wanted to make. You see, every bullet can be described with a step-by-step, cookbook approach, but there are tens of thousands of different styles and shapes you can make, and not all of them are made the same way! The same bullet may be made in slightly different ways with different presses and the dies which fit them. Instead, I try to teach the principles involved. That way, you know the terminology and won't be confused by thinking a die is a punch or a punch holder is a die. You will understand that every swaging operation expands the components upward in size, so that you won't try to put a larger part into a smaller hole except when drawing down (which you will know is different from and opposite to swaging). You will know that in a swaging press, the die screws into the ram and the external punch fits into the press top, in a floating punch holder, whereas in an ordinary reloading press used for swaging, the die fits the top and the external punch fits the ram. You will understand that a smooth, step-less ogive requires a set of dies that includes a point forming die, whereas a shouldered semi-wadcutter style bullet can be made in a single die. All these things will be familiar to you before you start. You won't need to be told specifically how to make every possible bullet, because you will understand the basic principles and how to apply them to any bullet. When we ship orders for dies, they come with specific, simplified 1-2-3 instructions that apply to the design you ordered. Sometimes these instructions are applicable to many calibers in a popular style, so we print the instructions on a form. Sometimes your bullet design needs specific, handwritten details and tips we discovered while developing the dies, and then we write special instructions for | |||
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you. But in all cases, if you are prepared with a good background of general swaging principles, you can avoid damaging the tools and begin making bullets with higher confidence. Swaging versus CastingEveryone seems to be familiar with bullet casting (melting metal and pouring the molten liquid into a split mould, letting it cool and shrink, and then opening the split mould halves so that the frozen bullet metal can drop out). Casting involves a lot of time and introduces quite a few potential sources of inaccuracy, but it works reasonably well within a limited range of capabilities. You have to have a lead pot and a supply of lead, a mould and mould handles, then a lubricator and sizer machine to prepare the bullets. The sizer machine needs sizer dies and base and nose punches to fit the shape and caliber of bullet. It also require lubricant to apply to the bullet. The first thing you have to do with casting is to melt a pot of lead, flux it and stir it, make sure that the dross and dirt is cleaned from the lead, ventilate the room and make sure no moisture gets into the pot and blows the hot lead out with a bang. You need to be reasonably careful about fire and burns, and about potentially toxic fumes (no eating or smoking, plenty of good ventilation). After about half an hour of this melting and preparation, you are ready to start casting bullets. The first few attempts usually make incomplete or frosty bullets, until the mould is warmed up. During the casting process, the mould contains liquid metal that is cooled to solidify on every single bullet made, so it is constantly changing diameter from thermal expansion. When you open the split halves, part of the mould is exposed to room temperature air while the rest is protected from it, which cannot fail to slightly warp the roundness of the mould. The two halves of the mould cannot be put together with zero tolerance, as they would be far too hard to swing open and closed again, so there is some degree of "slop" in the fit of the pivot and the alignment pins. Add up all these factors and you can see that a cast bullet has a limit of roundness and diameter control based on physics, rather than skill or quality of manufacture. A swaging die runs at room temperature and does not contact hot metal. It flows the metal under tons of pressure, squeezing out all air pockets and voids. The bullet takes its shape and finish from the diamond-lapped hardened surface of the die. The die is not split, but is a solid tube or cylinder with thick walls to hold the pressure. The bullet material goes in one end, and is pushed back out the same way. Two precisely fitted punches seal both ends of the die. One moves in and out to load material, and the other acts as an ejector. The problems associated with heat expansion, swinging split section alignment, and the time required to prepare are absent or minimized with swaging. In addition, the die can make a wide range of weights depending on how much material you put into it. A mould makes approximately one weight because you must fill it to make a bullet. These are just a few of the differences between casting and swaging. | |||
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2. What is Bullet Swaging?Before we talk about swaging a bullet, we need to make sure the concept of a bullet is clear. When we say "bullet", we mean the projectile or part of the cartridge that is propelled through the air. The news media in the United States often refers to a "bullet" as the entire cartridge with powder, primer, bullet and case. Bullet swaging has nothing to do with the rest of the cartridge, but concentrates on the part that flies to the target. In some countries, shooters refer to the bullet as the "head" or the "bullet head" and call the entire cartridge a "bullet". There is a good reason not to call the cartridge a bullet, as the general news media seems inclined to do. The bullet is inert metal without any propellant involved, which means that it should be treated as a precise metal product, not some dangerous component subject to transportation restrictions and tariffs. A bullet is as safe as a writing pen, probably safer: people have been stabbed with uncapped ball-point pens. I accidently stabbed myself once, stupidly, reaching into a coat pocket. Finding a "bullet" in the possession of an airline traveller should be no more cause for alarm than finding a coin. Unfortunately, through ignorance and imprecise language, the term "bullet" causes problems where it should not. Some of them are of practical concern to those who show their products and must carry samples. More than one new bullet maker has run up against unrealistic insurance, business licensing and zoning problems because of ignorance about what a "bullet" actually means. A bullet maker is a precision metal product manufacturer, who could just as well be making precision bearings or electronic fittings. But try to explain that to a bureaucrat who just found out you intend to make bullets in the home enterprise, or the hysterical airline security guard who scanned a couple of samples in your pocket, or the customs agent whose eyes widen as he reads your declaration of "bullet-making" equipment being taken into the country! Such a pity these things happen. The wise bullet-maker soon learns to discuss precision formed parts rather than bullets, around those who know nothing about the field. Corbin equipment can swage bullets from .123 diameter up to about 1-inch diameter (.998-inch is the 4-bore blackpowder elephant cartridge, for example). The "bullet" can be an airgun pellet, a swaged round ball, a shotgun slug, a fragmenting shot or powdered metal filled jacketed pistol bullet, a partitioned or multi-jacketed projectile, and it can be made of pure lead, various lead alloys, powdered metals pressed together with or without a jacket, conventional jacketed bullets with a lead core with or without other inserts such as penetrators or light plastic fillers to shift the center of gravity and create fast, light but long projectiles. In short, just about anything that can be launched from a small arm, be it airgun, shotgun, rifle or pistol, and some kinds of machine guns and cannons, can be swaged and is considered a bullet. | |||
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Bullet swaging (SWAY-jing, sounds like "paging") is the process of applying extremely high pressures (from 15,000 PSI for soft, unjacketed bullets to as high as 150,000 PSI for solid copper bullets) to materials contained in a very tough, extremely well finished die, so that the material will flow at room temperature and take on the shape of the die and the ends of the punches. A die is a vessel to hold the pressure. A punch is a rod that fits into the hole in the die and seals off the end. If you refer to a punch as a die and vice versa, you may cause some interesting errors when placing orders. One of the first things to learn is the right names for the basic parts involved in the swaging process. You wouldn't call a pistol a shotgun, would you? Probably not, or else you might get some odd-looking mail-order holsters! A business that is good at making swage dies probably will be buried in orders, with long waiting lists. Waiting up to a year to get your "die" and finding out everyone thought you wanted the "punch" that you asked for may be frustrating. Use the right terms and avoid this problem.
In swaging bullets, you will always be putting a smaller diameter object (lead, jacket, or a combination of both) into a slightly larger die cavity or hole. Each step in swaging increases the diameter of the components, until they reach the final diameter in the last die. Swaging never reduces the diameter. You will only have stuck bullets and hard ejection if you try to push a slightly larger part into a slightly smaller hole. This is the difference between swaging and drawing. You never swage anything "down". You never draw anything "up". In drawing, you do push a larger part through a smaller hole, to reduce the diameter. This kind of die is a ring, not a cylinder closed on one end. The jacket or bullet that you are reducing is pushed through the ring, and is decreased in diameter when it comes through the other side. We use drawing to make longer, smaller caliber jackets from shorter, larger diameter ones. Also, within some narrow limits, it is possible to make a smaller caliber bullet from a larger one, although this degrades the quality of the bullet unless special conditions are observed. Usually the difference in diameters has to be within 0.006 thousandths of an inch when you reduce finished bullets by drawing. Jackets can be drawn much more than this.
A jacket is the "skin" of a bullet, usually made of copper or a copper alloy with zinc (most commonly 5% to 10% zinc). Jackets can be used, or not, depending on the bullet design. A jacket isolates the lead core from contact with the barrel, and allows the bullet to be shot much faster without friction melting the core and smearing it in the barrel, which is called "lead fouling". Enough of that spoils the accuracy and is hard to remove. We'll discuss jackets in detail later. Bullet jackets properly designed for swaging are always made smaller than the finished caliber, then expanded by putting lead inside them and compressing it with a punch. The lead flows to fill the jacket, then pushes the jacket out a few thousandths of an inch to meet the die wall, which stops the expansion. One end of the die is sealed with a punch, which stops the end from popping off the jacket. | |||
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If you try to use a jacket larger than the die hole, it can't spring back slightly when you release the pressure. In fact, if you push a jacket into a die that is too small for it, the jacket will be trying to spring back to original size, and thus pressing itself firmly against the die walls. This causes difficult ejection and is hard on the equipment. The right way to swage bullets is to use jackets that fit easily into the die by hand, and lead cores which are small enough to easily drop into the jacket. Jackets of course have some wall thickness, generally from 0.015 to 0.035 inches (although there is no rule that says you can't make much thicker jacket walls if you want them). To determine the diameter of lead core which fits inside, you must subtract two times the wall thickness from the caliber, and then subtract an additional five to ten thousandths of an inch to allow for easy insertion, tolerances in the lead wire diameter, and the fact that you may have two or three steps with a small amount of expansion in each, to get to final caliber. Basic swage diesThere are two basic designs of swaging dies made by Corbin. All the specific styles of dies are patterned after one or the other of these basic designs. One design is a cylinder with a straight hole through it. The other is a cylinder with a semi-blind hole, having the shape of the bullet except that at the tip, there is a tiny hole (.052 to .120 inches is a typical range) fitted with a strong piece of tempered spring wire. The first design can be used for any sort of operation where two punches can form the desired shape on the end of the enclosed materials. An example would be a "Core Swage" or "CSW-" die, which takes in a piece of cut lead wire or cast lead pellet (the "core" of a bullet) and gives it a precise diameter with smooth flat ends and extrudes off whatever surplus lead there might be for the weight you desire. Three little bleed holes in the sides of the die, at 120 degree intervals, allow surplus lead to spurt out as tiny wires which are sheared off during ejection. Core swages are used to make the lead filling (core) a precise weight after it has been cast from scrap lead, or cut from a piece of lead wire. This kind of die can also be equipped with a punch having the shape you want for the bullet base, and another punch, at the opposite end, having the shape you want for the nose. Both shapes will be in reverse: the bullet nose is formed in a cavity in the punch, and a hollow base bullet would use a convex or projecting punch. This is what we call a "Lead Semi-Wadcutter" or "LSWC-" type of die. That doesn't mean you have to make a particular shape that you know as a semi-wadcutter bullet; it's just a short-hand way of saying you could do that, or make any other shape that has the entire nose right out to the full bullet diameter formed by pushing the lead into a cavity in the end of the nose forming punch. With most swaging dies, one punch always stays partly inside the die. It slides back until a ledge within the swaging press ram stops it. To eject the bullet out of the die, this punch is pushed forward toward the die mouth. It can be pushed by a pin or knockout bar incorporated in the design of the press (with a Corbin swage press), or it can be pushed by a plunger (with a standard reloading press). We call | |||
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this punch the "Internal Punch" because it always stays in the die. It is "internal" or inside, and never comes out during normal operation. It merely slides up and down, a distance slightly less than the die length, and stops within the die so as to close one end for swaging. It has to move from this position to the die mouth, in order to push out the finished bullet. The other end of the die accepts the material to be swaged. Obviously, that end has to be fitted with a punch that comes out all the way, or there would be no way to put the material inside. The punch which comes out, so you can insert material into the die, is the "External Punch". It is external to the die during the time you are placing the components in the die, and when you move the ram back to eject the bullet. The "Ram" is the moving tubular steel part of the swaging press that holds the die and the internal punch (in any Corbin press). With Corbin swaging presses, the external punch fits into an adjustable "Floating Punch Holder" in the press head or top plate. This assembly is often mistaken for the swage die, because in reloading, a similar-appearing reloading die fits the head of your reloading press. Swaging is "upside-down" from reloading, for reasons that will be clear by the time you finish this book. Again, the steel rods that push the material into the die, and seal the die against all that pressure during swaging, are called "punches". The round cylinder with the hole in it is called the "die". If you fit punches to a particular die, you have just made a "die set", because it is a set of matching parts that work together. You can have several dies and punches in a given set, because all the various dies in that set are designed to work in succession, one after another, to yield a final bullet shape, weight, and construction. The only difference between a "Core Swage" die, which we call a "CSW" die in the language of swaging, and a "LSWC" die, is the use of punches which have the final bullet base and nose shape machined on their ends, and of course the diameter of the die is made to form the final bullet diameter in the LSWC die. Usually the LSWC type of die makes either lead bullets, gas checked, or "Base-Guard" bullets (a superior kind of gas check that scrapes fouling out of your barrel with every shot fired). It isn't used for bullets that have the jacket covering up the bleed holes in the die wall, which includes most jacketed rifle bullet designs. The core swage die generally has flat punch ends and a diameter far less than the final caliber. It is used to prepare the lead core to fit inside a bullet jacket, in most cases (although you don't have to use a jacket—you can just swage the lead core to final shape in the next die if you desire to make a high quality lead bullet, such as a paper-patched or Gase-Guard style). Lead bullets can be made either in one die (the LSWC) or in two dies (the CSW and CS types, or the CSW and PF types). Jacketed bullets generally require at least two and sometimes three or more dies. When we make the die, we need to know what it will be used for. If you say you want a .308 core swage die, you probably do not want the hole to be .308 inches because a core swage has to make a core that fits inside a jacket, and the jacket will usually be about .307 inches on the outside before swaging. The wall thickness of the jacket might be .028 inches at the base, so the core would have to be no larger than .307 minus twice .028 (twice the wall thickness), or .251 inches. | |||
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So, we need to have a sample jacket or at least know what jacket you intend to use, or at the very least to know the diameter you really want for the lead core. If you supply a jacket, or specify one of ours, then we can determine the best core diameter to fit into it. You can cast scrap lead in a core mould, or cut pieces from a spool of .247 inch diameter lead wire to easily drop into this .251 bore die, swage them up to .251 inch diameter, and then they'd fit nicely into the bullet jacket. (There would be two more steps to expand the core inside the jacket, blowing the jacket out like the skin of a balloon, and then forming the ogive on the bullet to finish it). But if you wanted to make a lead .308 diameter bullet for a .30 Mauser pistol, then we'd make almost the same kind of die but we'd make it with a bore of .308 inches, and fit it with the right kind of nose and base punches. So you see that even if the dies look similar and work in a similar way, their purpose really makes them different dies. That's why we need two different names for them. It helps avoid a lot of unnecessary explanation and errors. Perhaps you might order a .308 LSWC die, maybe with an "Auto-loader" nose and a "Cup Base". We would use the short-hand "AL" for Auto-loader, a sort of rounded semi-wadcutter shape, and "CB" for Cup Base, which is a shallow concave base form. To us, the term "semi-wadcutter" is a general description for a bullet style that can be made using a punch to form the nose, instead of a point forming die. The Target Wadcutter, Button-Nose Wadcutter, Keith, Auto-Loader, and even round nose SWC styles are all subsets of the semi-wadcutter group, since every one of these styles is made in the same die just by changing the nose punch. Two other kinds of dies that are made with a straight hole and two full-diameter punches are the "Lead Tip" die and the "Core Seat" die. These don't have any bleed holes around their middle. The core seat die is also called a "Core Seater" and abbreviated "CS". The lead tip die is also called a "Lead Tip Former" and is abbreviated "LT". It is not the same thing as a point former or "PF" die. The purpose of a core seat die is to expand the jacket, which is made slightly less than final diameter, and at the same time achieve a very tight fit between the core and jacket. You can use either a punch that fits into the jacket, to make open tip style bullets, or you can use a punch that fits the die bore, and thus make large lead tips. The use of a CS die to make lead bullets (after first swaging the lead core to exact weight in the CSW die) is a perfectionist's way to build lead wadcutter or semi-wadcutter bullets: it can be more precise because you separate the pressure needed to extrude surplus lead from the pressure required to form the edges of the bullet nose and base. In a LSWC die, the pressure stops building when the lead begins to extrude through the bleed holes. Thus, some shapes of bullets with deep nose cavities or hollow bases and sharp edges may not receive enough pressure to fully take on the exact punch shape, if that pressure is higher than the pressure which causes lead to spurt out the bleed holes. By first using a CSW die to adjust the weight, and then using a separate CS die to form the nose and base, the pressure issue is resolved for all shapes and styles. | |||
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A punch with a cavity in the end makes the bullet with a semi-wadcutter shoulder (the edge of the punch must be in the neighborhood of .02 inches thick in order to stand the high swaging pressures). A core seating punch with a projection on the end, usually conical, makes a hollow point cavity in the lead core. Of course, you can use flat, domed, slightly convex, or highly pointed punch shapes to suit your desires, and make virtually any kind of base you want just by changing the punch. Often this will be the internal punch, but you can have the die built with the base punch being external if you wish. The reason we normally make the nose punch external to the die is because usually people change the nose shape much more often than the base, and it is easier to change the external punch in seconds without removing the die from the press ram. Technically it would not matter which punch made the nose and which made the base. The purpose of the lead tip forming die is to finish the very end of a pointed (spitzer) bullet, and it isn't normally used for semi-wadcutter or large lead tip bullets. It looks just like a core seater, but the bore diameter is slightly larger than the final bullet size, whereas the core seater diameter is just slightly smaller than final bullet size. The internal punch of a lead tip die is designed with a cavity to reshape the extruded lead tip of a sharp-pointed rifle bullet so that it looks perfect. It cannot form the entire ogive because the edge of the punch, which must withstand tons of swaging pressure, cannot be paper-thin and survive.
We started this section talking about two general die designs, one with a straight hole through it, and one with a semi-blind hole. This second kind of die came about because, try as you will, there isn't a reliable way to make a straight-hole die form a smooth curve from shank to tip. (The bullet nose curve is called the "ogive", pronounced OH-jive, and comes from the French ogee which is the bullet shaped curve over a doorway). That punch with the cavity machined in the end must have some thickness at the edge, and this edge will impress itself on the bullet to make a shoulder. There's even more to it than that: if you try to push a jacket into the cavity in the punch, the edge of the jacket will strike the edge of the punch. It won't reliably jump over that edge, but instead either the jacket or the punch will be crumpled up. In Corbin dies, the jacket is far weaker than the punch, so it folds up. So, that leaves the problem of how to make a typical rifle-style bullet, or a smooth rounded or angled bullet nose of any type, not having a lead tip from where the jacket stops to the end of the bullet. The semi-blind hole die is used whenever the nose or base of the bullet has to turn inward, away from full bore diameter, without a shoulder or step. Conventional rifle bullets, boattail bullets, and modern jacketed handgun bullets with the jacket curving or angling smoothly inward from the shank to the ogive all require the use of this die design. By "semi-blind hole", I mean that the hole in the die is not straight through the die, but is shaped like the bullet itself. At the tip is a very small punch to push the bullet out by its nose, and this punch is retracted a short way up into its little | |||
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access hole so there is no possibility of the bullet material pressing against it (which might otherwise bend the small diameter punch under those tons of pressure). The "Point Forming" die, which we abbreviate "PF", accepts either a lead core, or the seated lead core and jacket combination swaged in the core seat die. A full-diameter external punch shoves the material into the point forming die. The material is compressed inward in the small end of the die, giving the bullet its smooth curve or angled nose (the ogive). The pressure also expands the shank slightly to final diameter. The bullet material follows the die wall, right up to the ejection pin hole and into it, if you push too far. This would put a little parallel "pipe" on the tip of the bullet, which means you need to back off the depth adjustment (the punch holder) just a little. The smallest tip which you can put on the bullet using the PF die is the diameter of the ejection pin. The smallest ejection pin that can be used is one that will withstand the ejection pressure without bending. If you happen to forget to apply swaging lubricant, or if the jacket is larger than the die cavity diameter, the pressure required to eject the bullet can go considerably higher than the design parameters. This means that the ejection pin needs a little extra diameter as a safety margin. A typical ejection pin (the internal punch for a point forming die is usually called an ejection pin) for .224 or .243 caliber might be in the .062 to .081 inch diameter range, depending on the expected ejection pressures and the abuse expected for the die. Dies made for professional bullet makers, who know how to stop short of bending the punch if anything goes wrong and who won't be upset if they do need to replace the ejection pin now and then, might tend to be closer to .062 inch; dies made for experimenters who will be exceeding the design limits frequently tend to have larger ejection pins, as do dies made especially for lead tip bullets. If you make a round nose bullet, a truncated conical pistol bullet, or even a flat tip rifle bullet in the PF die, it works very nicely for either open tip or lead tip, depending on how much lead you put into the jacket. If you make a bullet with the jacket curved around to the diameter of the ejection pin, then the pin will press down against the end of the jacket and push the bullet out of a well-finished, diamond-lapped swage die with relatively low force. But if you want a small, sharp or rounded lead tip, the ejection pin spoils your plan by making its own flat circle on the very tip of the bullet. To form a small lead tip on the bullet, you would need to leave a little extra lead projecting from the end, which the ejection pin will deform somewhat during ejection, and then use a "lead tip forming" die, or "LT" die, to shape up any extra lead. The lead tip die accepts the nearly-completed bullet from a point form die, so it has a bore diameter slightly larger than the finished bullet size. This works only because the pressure needed to shape the lead tip is so low that the bullet shank will not expand. In fact, since the lead tip die is just minutely larger than the point forming die, perhaps only .0005 inches, it can assure that the bullets will be more parallel and have almost no "pressure ring" at the base. | |||
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The internal punch of the lead tip die has a cavity that is shaped not exactly to the same outline as the bullet ogive, but with a slightly shorter radius. For instance, if the bullet had an 8-S ogive (we'll explain this in detail later, but the ogive radius is the length of the radius used to swing the arc that gives the bullet ogive its shape), the radius of the cavity shape inside the lead tip forming punch would be perhaps 7S. That is a shorter radius. The result is that the lead tip is formed and the surplus lead pushed down at a slight shear angle between the wall of the punch and the ogive of the bullet. If you leave the right amount of exposed lead, the punch will form a neat lead tip with a very slightly different ogive curve from the rest of the bullet. If the punch shape were made precisely the same as the point forming die, the edge of the punch would strike the ogive of the bullet and create a ring, instead of neatly reshaping the tip. Bear in mind that the LT die is not used by itself, nor is it used instead of a PF die. If you use one at all, it would be to follow a point forming die. Remember, the jacket edge won't jump over the punch edge. If you already have a curved jacket, from the PF die, then the edge will slip past the cavity and let you shape the lead tip. A LT die can also be used, in some cases, to help close the open tip of a jacketed bullet more tightly than could be done in the PF die alone. With care, a bullet maker can learn to push the open end of the jacket nearly closed, by gently using trial and error adjustment of the punch holder. Not every ogive shape or design lends itself well to this operation, but enough of them do so that it is worth mentioning. Rebated BoattailsWhat about bevel bases or boattail bullets? Those also have the bullet smoothly angled away from full shank diameter. So, they also require a variety of the point forming die which is used to shape the base instead of the nose. The boattail bullet has largely been replaced in swaging circles by the superior "rebated" boattail, abbreviated "RBT" as opposed to the more conventional "BT" for boattail. Why are most custom bullet makers using the RBT instead of the standard boattail base? There are three reasons:
1) A regular boattail bullet tends to act like the focusing nozzle of a water hose during the moment it emerges from the barrel. Hot powder gas rushes around that boattail angle, flow up the sides of the bullet, and continue in a smooth, laminar low pattern right around the front, where they break up into turbulent flow and make a fireball of gas—right in the path of the bullet! You can get up to 15% increased dispersion at the target just from the buffeting the bullet gets by shooting through this ball of gas. A flat base bullet deflects most of the gas in a circle of fire, expanding rapidly out from the bore with a clear space directly in front of the bullet. The edge of the flat base acts like a "spoiler" to break up the | |||
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laminar flow before it can get started. And so does the sharp shoulder on a rebated boattail! How does a 15% improvement in accuracy sound as a benefit of using the RBT design?
2) The boattail bullet tends toward more bore erosion than the rebated boattail, because gas pressure on the boattail tends to peel it back away from the bore and let some gas up past the bottoms of the rifling grooves, where it cuts the bullet and the barrel like a hot cutting torch. The rebated boattail has a 90 degree shoulder that takes the pressure parallel to the bore, instead of at a compression angle away from it. How does increased barrel life strike you as a second reason for using RBT bullets instead of the regular BT style?
3) The tooling lasts longer, costs less to build, and is more easily built to high standards of precision. Corbin Manufacturing has perfected a method of using two dies, which we call the "Boattail 1" and the "Boattail 2" dies, as a set, to produce a virtually flawless and highly repeatable rebated boattail. Instead of making the boattail angle so it can be higher on one side or at a little slope like some of the factory production you see today, this system guarantees that the boattail will start precisely at the same point on one side of the bullet as it does on the other, every time.
With all these benefits, there is hardly any reason to make standard boattail dies these days. The RBT has been proving itself all over the world for more than 30 years to those who are wise enough to give it attention. However, if you were to ask what base design I would generally recommend for jacketed bullets up to 250 yard range, I would be unhesitating in saying a flat base. Rebated or not, a boattail does not give you superior accuracy in and of itself. It gives you less base drag. Whether or not that translates into better accuracy than a flat base hinges on whether the increased drop or higher trajectory arc gives you any problem hitting your target, and whether there is much cross wind to push the bullet off course. Usually at subsonic velocities, the rebated boattail gives you a much greater benefit in comparison to other drag factors, than it does at Mach I and above. The shock wave causes far more percentage of total drag at supersonic velocities, so making the nose more pointed produces more effect than streamlining the base. The best silenced, subsonic bullets for special ops have been rebated boattails with a blunt round nose (and other special features for expansion). Bevel BasesBevel base bullets are made by seating the core in a special "point forming" die instead of the usual core seating die. The jacket is put into the die, and the lead is pushed into the jacket. The base of the bullet flows down into the short, beveled section of the die (it can't be a punch cavity, remember, because the edge of the | |||
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punch would cut the bottom of the jacket). You could also seat the bullet in a normal core seating die, and then reform the base in this die, but it would be redundant. A lead bevel base bullet could be made in two steps: swage the lead core using a rather large, almost finished diameter core swage, and then push the bullet into the special point forming die backward, using a nose punch as the external punch. Come to think of it, any lead bullet with a smooth ogive (no semi-wadcutter shoulder) can best be made by using first a CSW die to adjust the weight, and then a PF die to form the ogive. Without a jacket, you don't need the CS die, the purpose of which is to expand the core into the jacket and form a tight, parallel shank. Dies Classified by Press TypeWe've talked about the basic design of bullet swage dies, in regard to their function. There is another category for classification of swage dies, and that is by the kind of press used to operate them. Swaging dies can be designed to operate in a reloading press (with severe limitations on pressure and precision), or in a number of different models of bullet swaging presses, both hand and hydraulic-electric powered. Years ago, we worked out a system of making standard parts for dies that would cover a wide range of calibers, and thus cut the cost of swaging through efficient use of what I call "semi-custom production". We designed presses and die sets so that we could build similar punch and die blanks for certain ranges of calibers and bullet lengths, and then choose among perhaps three die body lengths for every caliber from .12 to .458 in the hand presses, or from .224 to .998-in the dies for our big hydraulic presses. We didn't have to design and build each die from scratch, because we built a standardized system for determining the minimum requirements of strength, die length, stroke length, punch geometry and strength, steels and heat treatment. We could run hundreds of blanks for each of the various presses, then hand-finish the cavities and hone the rough-finished punch blanks to a perfect fit during the custom phase of each order. It combined the economy of mass production with the flexibility and precision of custom tooling. Corbin swaging dies are up to ten times less costly than competitive dies without any sacrifice in precision because of this semi-custom production technique, and the fact that we design and build several different presses to take full advantage of the kind of operations you might want to undertake. The classification by press type also defines the die thread and diameter. The last letter in the catalog number identifies this classification. Dies with a catalog number ending in -R (such as the PRO-1-R) fit a standard 7/8-14 thread reloading press with an RCBS-type button shell holder ram. The die screws into the press head like a reloading die. The external punch slips into the T-slot of the ram. You do not also use a shell holder, since the punch base is made to simulate one. Dies with a catalog number ending in -M fit either the discontinued Silver Press, or the current S-Press. They are being phased out of stocking status in favor of the -S dies, which are larger and stronger, and fit the current S-Press or its | |||
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predecessor, the Series II press (discontinued). However, we will continue to make them on special order, just not as a stock item. The -M dies have a 3/4-inch diameter main body, a thrust-adsorbing shoulder, and a 5/8-24 threaded tenon. The die screws directly into the press ram, and the external punch is held in a Corbin floating punch holder in the press head. An example of an -M type die is the LSWC-1-M, a lead semi-wadcutter die. The current type -S dies fit the discontinued Series II press or its replacement, the S-Press (Catalog number CSP-1). An example of a set of -S dies is the FJFB-3-S, a three-die set. The -S dies have a longer and larger diameter body than the -M type, being 1-inch diameter. By using the same 5/8-24 threaded tenon, the thrust shoulder is wider and thus spreads the force over a wider area (the top of the industrial chromed alloy steel ram in Corbin presses). This also means the S-Press can accept both the older -M dies and the current -S dies. A bench-type hydraulic powered version of the S-Press, called the "Hydro-Mite", also uses these -S dies. Finally, the type -H dies are made to fit the Corbin Hydro-Press, Mega-Mite hand press, and Hydro Junior press. These dies are typically made in a 1.50 inch diameter, with a length appropriate to the maximum bullet weight to be produced (up to three inches). The thread tenon is made with a 1-inch 12 thread (meaning 12 turns per inch) to screw directly into the press ram. The external punch fits into the huge FPH-1-H floating punch holder, in the press head. A "positive stop" FPH-2-H punch holder is also available for extreme high precision weight control. Dies for Other PressesSpecial diameters of dies can be built to order, either to fit Corbin presses or other presses. Diameters of up to four inches with nearly any desired thread can be made. Usually it is best to use a standard die that fits one of the Corbin presses, rather than to spend very much on custom work to fit some other press. In the first place, the cost of special replacements and additions can quickly use up any savings in using an existing press versus buying a standard swaging press. Often I have heard "I already have a press that I want to use" and the meaning is, "I don't want to spend money for another press." I agree, and would do the same, but only if the cost of building the custom dies and punches and making them work in this nonstandard press (for swaging purposes) is still less than just buying a regular swaging press. Often it costs more to fiddle around with special jobs than it does just to buy a standard swaging press. And then, from that point on, you don't have to worry about any special replacement parts, or additions that also have to be custom made (meaning both fairly long production delays and additional cost). Usually, the design of a swaging press gives you a big advantage in speed, accuracy, and safety over using other kinds of presses. After all, a pants press, a wine press, a full court press, and a printing press all are variations on the term "press", and they are not suitable for reloading. Having said this, it is still possible to have custom dies built for just about any press you own. Just bear in mind that there is time involved in making working drawings, checking the stroke and ejection position, getting special thread taps and dies (sometimes), setting up the tool | |||
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ing for a onetime job, and other costs that have long been amortized over thousands of dies when you choose a standard production design instead. Besides, we may have spent a couple of decades and tens of thousands of dollars in testing and improving our standard tools and presses. Building something for the first time in a different design often requires some investment in development, which may be a waste of your money if we've already done it a thousand times before in a different and better system, which would be yours if you just got the right platform to run it (the proper press). With a different, special tool, you get to pay for any unforseen development requirements. With our own products, we already paid for development and you get to benefit from that. It's usually a better deal. Swaging Principles1. Always swage "up", never "down". Swaging down is a contradiction. You "draw" down, by pushing something through an open ended ring die, like our JRD-1 jacket drawing die, or BRD-1 bullet reducing die. Drawing makes the part smaller in diameter and longer. It can also cause separation of the core and jacket if done to excess. Swaging makes the part shorter and larger, and tightens the grip of the jacket on the core. 2. Pay attention to the instructions. If there are special written notes with your die, they are important because they modify or improve the general instructions and replace them. If there is a difference between specific notes sent with your set of dies, and anything published in general (as in this book or in general printed literature), follow the special written instructions in any respect where they may differ. Swaging is partly an art, and various materials or sizes may react differently to the same general kind of operations. 3. Use the right terminology! I cannot stress enough how important it can be to read what you have before you start to use it, and order the right part numbers and names of parts. People call the external punch everything from a "pin" to a "ram" to a "die" to a "die punch". How are we supposed to know what you mean? If you order it wrong, you get to pay a restocking fee or, if it is custom made for you, then it may not be returnable. A die is the vessel or cylinder that holds the material. A punch fits into the end of the die and pushes on the material. A "pin" is part of the pivot system of the press, or the wire ejection pin that fits into a point forming punch. A "ram" is the moving steel drive component of your press into which the swage die screws. There is no such thing as a "die-punch" or a "punch-die": putting terms together to suit yourself just confuses everyone. 4. Use the right materials! A set of dies made for a specific jacket, a certain lead hardness, or a certain alloy and size of copper tubing, may be able to work with other materials but probably not without adjustments to the punch and/or die dimensions and possibly not without developing differences in technique. Nearly all problems with broken dies and stuck parts or improper sizes comes from the use of materials other than those we used to develop the tools. Hardness, grain and dimensions make a huge difference in your success. | |||
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3. Bullet Swaging SecretsBefore I start telling you about the various kinds of swaging presses and dies that work with them, and why you might want to select a given type of press and die for a certain kind of bullet making, it would be useful for you to know some facts that have taken decades to figure out, and which most of the people who have figured them out wish to keep from you, since it might affect their own income if you knew. If you don't care to wade around in the backwaters of history, skip this chapter and go on to the "How To" chapters that follow. It isn't absolutely necessary to be aware of all the misconceptions, phony physics, and junk science that is tossed about as if it were gospel. A lot of people make a good living based on these misconceptions, whether on purpose or because they believe it too, and it is not helping them a bit if you become aware of the errors in thinking that make this possible. But I suppose someone has to support those people: you can, if you wish! The Myth of ExclusionThe most common misconception about bullet swaging is that only a few people really have the money and expertise to do it right—that equipment to make a good bullet is far too costly for you to buy, and the techniques are filled with "secrets" that only a few bullet-makers are smart enough to understand. In other words, stay away from swaging because (1) you are not smart enough and (2) you cannot afford the right equipment. Leave it to the "experts" who know best, in other words... the same "experts" who are eager to tell you this, and to scoff when you mention that you might have found a way to try it yourself. The reason this myth is repeated in print every year is simple. Think about it: if you were making a reasonably good income from selling your own custom swaged bullets and someone asked you to tell a magazine audience all about your business, would you tell them "It's easy: anybody can do it with a little reading and a few hours of experimenting with moderately priced equipment!" Or, would you be more likely to think about it and then say "Man, it's hard: the only equipment that works costs thousands of dollars and takes years to figure out. You guys are way better off just to pay me to do it for you and keep on buying my bullets!"? Always remember to consider the source when you read anything, and follow the money trail. (Yes, I'm aware of the irony, but you already bought this book so I can afford to be honest in the writing of it!) It works in almost everything in life, not just bullet swaging. Before you read something, try to figure out who wrote it, who pays them, and why they might be influenced in their comments and opinions by the source of their income. | |||
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It's not a conspiracy: it's just how life works. Everyone has an interest in protecting their source of income. The more unusual the occupation, the less likely it is that the person will say anything that would encourage you to go into competition. Successful people learn early how to get good information from shaded stories without necessarily accepting everything at face value. All this means is that when you read articles by or about bullet makers or their products, be aware that the products were made by human beings, not mythological Titans. Odds are pretty good that, given the right equipment and information, you could do the same thing. Or maybe, even better. The Myth of the ShortcutIn a long and largely successful business career, I've found that the only reliable income is that generated from trading good information, services and products. Perhaps some have become wealthy by chance, or by trickery, or by other transient opportunities, but by and large what works is providing consistent good value. The surprise is that so many people think otherwise, and spend their lives looking for shortcuts. So much effort is expended in the search to avoid putting out any effort! It isn't fast or easy to build a reputation for good value, but the alternatives are too unreliable, even putting moral considerations aside. This myth isn't just for bullet makers, but it seems to come up frequently in discussing a new bullet business with someone who wants to make back his investment in a hurry. "What's the hot item to make? What would make the most money in the shortest time?" Well, here is where I could take a shortcut myself and make up some foolishness that would insure a quick or bigger sale. I could speak eloquently about whatever this client was sure to have seen on the covers of the latest gun magazines, and it would be easy to make a good case for whatever caliber, style, or gun was featured as the magic carpet one could ride to riches by making that particular bullet, or one for that particular gun. But unless it was true, I wouldn't do it, and while there is some truth to the idea of following the latest trends, it isn't likely to result in immediate riches. There are not enough potential bullet makers to treat clients like used car buyers, even if I could somehow justify acting that way. Either my clients have to be successful, and continue to purchase equipment and supplies as they grow, or the swage die business will not work well enough to be viable. After more than three decades of providing income for six families of Corbin employees, it's fairly obvious that there must be something reliable and long-term behind the ideas I am discussing here. It's not very likely that thousands of handloaders would come back, year after year, for products and ideas that didn't meet or exceed their expectations. Many people do, in fact, make a good living using Corbin equipment to produce high quality custom bullets for other shooters. You see their ads every time you pick up a gun magazine. They start small, often just as a hobby, and their interest and business grows and expands to other equipment, which Corbin de | |||
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signs and manufactures. Our design and engineering work, as well as marketing help, is critical to the success of most of our clients (there are some who had everything figured out from the start, but not many). Because a substantial part of our income and reason for our own success has been based on appropriate advice and honest dealing with our clients, your trust is a critical factor in Corbin's very existence. We continue to have backlogs for our work primarily because people know that they can trust in the essential facts that are spelled out in our books. The myth that you can get there by some shortcut inspires countless other people to try, year after year, making a brief appearance and then disappearing forever. In their wake are abandoned and disgruntled would-be bullet makers, who may get such a bad taste for swaging from the experience that they never want to try it again. That is, of course, my main worry from a business point of view. It doesn't take too many shortcut takers to spread a bad feeling about what can be a marvelous technology when done correctly with well-made tools. Shortcuts are what allows equipment to be made more cheaply, by using cheaper materials, taking less time to fit and finish the components, or skipping most of the tests and rework that might be necessary if a reasonable quality control procedure was in use. But a bullet-maker could forget the reason cheap copies of good equipment are cheaper, and think all such equipment is equally flawed. The same myth can affect the bullet-maker, even when he is wise enough to purchase good equipment. Taking shortcuts in the process of making bullets, in order to make them faster, can result in less satisfactory bullets. The custom bullet market is not interested in cheap bullets: it exists because of the need for bullets of superior performance. Today, you can hardly pick up a gun magazine without reading something about one of my clients who makes a better custom bullet. Custom bullet making has been elevated by these people from a dark art to a serious, mainstream part of the firearms industry. But these bullet-makers, by and large, did not take shortcuts. They spent an average of 18 months building up to the point where they could show a profit. Some did it in less than a year, others took two or more years. They built a business, they didn't trick one into existence. You might not care at all about the commercial possibilities for custom bullet making, but it affects you anyway. The mass producers have been forced to come up with their own premium lines of bullets and have often purchased bullets from my clients instead of trying to come up with their own. The fact that hundreds have turned to bullet swaging as a way to make a living, and thousands more use it as a way to make a little spare cash on a part-time basis, means that your bullet selection has improved vastly in the past few years. Guns of a type that you might not have considered using for defense twenty years ago can now be put into service, since the bullets have improved their performance so much. Game animals that you might have wounded and lost twenty years ago can be cleanly taken without the suffering and without the long hikes to the bottom of canyons where the game was able to run and finally die a lingering death because of poor bullet performance. Hunting is more humane when the bullets perform flawlessly on the first shot. | |||
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Your scores at benchrest, metallic silhouette, IPSIC, and even blackpowder matches can be higher than they were "back then" because of the tremendous amount of research and testing done by all the custom bullet-makers. Laws have been passed or modified based on certain kinds of custom swaged bullets that did not come from any mass producer. If you don't think you have some interest in commercial swaging already, think again! None of this happened by taking shortcuts, either in the making of the equipment, or in the using of it. The Myth of CarbideThere is a great deal of emphasis placed on the buzzword "carbide" at this time. Carbide is a rather generic term that covers a lot of ground, rather like the word "chlorophyll" back in the 1960's, or any other semi-technical term that is turned into an advertising catchword. There is no such thing as a single kind of die material called "carbide", except in the minds of ad writers. When you heat any tool steel to a high enough temperature, some of the carbon in the material dissolves in the nearby iron, and forms a ferric carbide material which can be captured in the frozen matrix of the steel if the temperature is lowered quickly enough. The ferric carbide trapped in the steel mixture is primarily what gives the steel its hardness. The structure also has a matrix of iron and other elements, which form complex compounds that give the steel ductility, ability to remain hard at higher temperatures, corrosion and shock resistance. All hardened steels have "carbide" in them: that's what makes them hard. If you systematically reduced the amount of iron and increased the amount of carbon that dissolved in the iron that was left, you would wind up with a very hard, but also very brittle material. It might be almost "solid carbide" but it wouldn't be very strong. By forming compounds of tungsten and other metals with carbon, the General Electric company (and others) developed commercially acceptable variations of "carbide" in a wide variety of grades. General Electric's trade name of "Carboloy" was applied to some of these. The important thing to note is that there are variations that are nearly as soft as hardened tool steel, and others that are so brittle that they shatter like glass if force is applied incorrectly. Some carbide materials can handle high temperatures and some fracture when heated and cooled during use. Some make good tool bits, and some are only good for a thin coating on the surface of a hardened steel bit. Some are reasonable to machine accurately, and some cost a fortune to machine compared to making the same shape from a good tool steel. If you were to be faced with the decision of a material from which to build dies for a high speed punch press, working at 40 strokes per minute or more, and making several million bullets, then one of these grades of carbide material could give you higher temperature operation and thus longer life than a tool steel die. Because the harder materials are more abrasion resistant, you would be able to run the dies for a longer time before replacing them. | |||
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They would still need to be lubricated: the idea that carbide dies need no lubrication is foolish. It is like saying that because your car engine might run 100,000 miles without changing the oil, you don't need to change the oil. It might run 250,000 miles if you did! It is necessary to consider value to make a good decision about die materials. Value is the cost of the die amortized over the number of bullets you expect to make, considering the amount of wear which will take place before the bullets are no longer acceptable quality. It is somewhat subjective, since one person might consider a die "worn out" when the bullet diameter increased by 0.001 inches, and another might find that the 0.3090 bullet shot even better than the standard 0.3080 in his gun. The point where you no longer consider the bullet diameter acceptable determines the life of the die, for your application. Wear is related to heat and abrasion. If you operate your dies in a hand-fed system of any type, it will be impossible to make more than five or six bullets a minute. At those stroke rates, any heat from friction would dissipate into the air before the next stroke. There would be minimal heat buildup, so that normal swaging lubricant (Corbin Swage Lube) would be sufficient to protect the die and the components from frictional abrasion not caused by dirty components or by polishing compounds embedded in the jacket material. In a power-fed system, it is possible to stroke the press so fast that heat cannot radiate away into the air as quickly as it is generated, until the die becomes quite warm. It reaches a stable high temperature by radiating heat into the air, and into the frame of the press. Swaging lubricants may not stand this high temperature, so the metal surface needs to be made of something that will remain hard and resist abrasion without as much lubrication. Certain grades of carbides will handle the job. Value is indicated by first estimating the tolerances which are acceptable for the bullets, and then figuring out how long a set of dies will give that range of tolerances, and how many bullets are made with each set, for what price. The lowest cost per bullet indicates the best value, all other things being equal. In the high speed punch press, a set of dies might easily cost $3000. They might slowly wear to an unacceptable tolerance after two million bullets were made, at a cost per bullet of three thousand dollars divided by two million bullets. This is a cost of 0.15 cents (not fifteen cents, but fifteen hundredths of a cent) per bullet. In this kind of operation, properly made tool steel dies might only last 50,000 bullets, at a cost of about $300 for the dies. That is 0.60 cents (sixty hundreds of a cent) per bullet. Obviously, the value is four times greater for using the carbide dies in this application. One might reasonably expect to make two million bullets on a punch press system: at 40 strokes a minute, and a bullet per stroke, that is only about 104.167 days or about 3.5 months—assuming the punch press is run eight hours a day, which isn't unreasonable. But even the largest and most successful custom bullet maker seldom turns to punch presses. The average custom bullet operation (if one could ever say these outstanding operations are anything close to "average") turns out about 50,000 bullets a year. After all, the market is limited and the price is fairly high (worth it, | |||
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but not cheap). You probably wouldn't make one million bullets in a lifetime of hand swaging. If you could make two bullets a minute, and worked at it every weekend for four hours, you'd only be making 24,960 bullets a year. When run at less than ten strokes a minute with proper lubrication, the high-carbide content die steels used by Corbin hold acceptable tolerances for at least 500,000 bullets, and some have made over 1,500,000 bullets in commercial operations started years ago. Assuming the dies would make 500,000 bullets, this means your $300 investment in dies would last for over 20 years if you made two bullets a minute, working every weekend for four hours, every week of those years. If you are just now turning 20 years old, you'd be 40 before you needed to buy another set at that rate. If you expected to live to be 100 years old, you would have a lifetime of bullet making on just three sets of dies, for a total cost of $900. Now, most people don't make anywhere near 24,960 bullets a year unless they are in business to make bullets. The odds are great you'd never make 500,000 bullets in a lifetime. But just suppose you did. Your cost per bullet for determining die value would be $300 divided by 500,000 bullets, or .06 cents (six hundredths of a cent) per bullet. In your lifetime, if you made 1.5 million bullets, you'd use up three sets of dies, so your total cost per bullet would be $900 divided by 1.5 million bullets, or .06 cents. This is for using tool steel dies. If you purchased $3000 carbide dies, you would not get one bit more accuracy or any better die, other than the fact that long-term abrasion resistance would be less, so you could get by with one set of dies for your lifetime. We assumed you might live 100 years, and make 1.5 million bullets. Your cost per bullet with a carbide die set would be .20 cents per bullet ($3000 divided by 1.5 million bullets). The steel dies are three and a third times better value for this application! That is 333% more value for your money with the steel dies. The reason I've gone so long into this is not any animosity toward "carbide", but because of the widely-held perception that just stamping the word "carbide" on a die automatically blesses the product with supernatural powers and makes it somehow more accurate. A die is only as accurate as you can make the hole. It is a lot easier to make a good die from a material that can be worked in its annealed state, then hardened and given its final adjustment in size with diamond lapping in the hard state. The easier a job is to do, the less it has to cost. So, you get more value: the same accuracy for far less money. Obviously, it is much easier to promote the myth, than to explain the facts. Advertising is sold by the column inch or fractional page, or by the word...and it costs a lot more to educate than to dazzle the reader. Fortunately, a book has plenty of space for education and you've chosen that path rather than just allowing yourself to be dazzled. Following the "carbide worship" path, the term "ECM" or "EDM" sometimes is waved about as a sort of accuracy magic wand. The terms refer to "electrochemical machining" or "elecrical-discharge machining". ECM is a form of "reverse plating" where metal is removed from the surface of the work by a strong flow of | |||
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electricity through a conductive electrolyte solution. EDM is a form of "spark erosion" where an arc burns away tiny pits in the surface and eventually removes it in a controlled manner, often under an insulating solution that carries away the eroded metal. Electrochemical machining is a last resort, not a step up. It is used when there is no other practical way to machine a part, because it is very costly, slow and difficult to make the hole precisely the right diameter and shape without going to much higher expense than with traditional machining techniques. ECM has its uses, one of which is to machine carbide materials that simply cannot be cut any other way. There is nothing inherently more accurate about ECM. It costs fortunes in equipment just to make it the same accuracy as lathe boring, reaming, and diamond lapping. Using ECM makes sense when you can't cut the material in a more traditional way. People who sell ECM machines are the first to tell you this. There is nothing inherently "more accurate" in using electrical machining as opposed to diamond lapping. Thin, fragile sheets of metal or brittle, hard carbide materials are best machined by ECM, but materials which can be machined with a faster traditional method should be. One who simply swallows the advertising hype is set up to spend extra money without getting the extra value. If I thought that there was better value for my clients in selling them $3000 dies, I'd certainly have no reason NOT to do it! I'd rather get ten times as much for a set of dies, if I could justify it to myself and to my customers. But for the past 30 years I've been proving over and over that it isn't good value for this application. What, exactly, is the benefit, other than making more money for me? I'll just have to rely on the good judgement of ten more handloaders, instead, to make the same amount! The Myth of Equating BC with AccuracyAnother myth is that aerodynamic shape is synonymous with accuracy. Years ago, I made some bullets that were just cylinders without any ogive at all, and fired them from a benchrest rifle in .224 caliber into a group that measured about 0.2 inches center to center. Then I fired another group made with 6-caliber ogive spitzer bullets made exactly the same way, with the same weight and diameter and the same materials. These made almost exactly the same size group. The gun was at its limit and the bullet shape had no effect on accuracy, except that the cylinders landed a little lower on the target (more drag, so they dropped slightly more). In our work for various government agencies, Corbin made dies that we called the "Ultra Low Drag" or "ULD" design, many years before the popularity of the so-called "VLD" design of the late 1990's. The two designs are quite similar. In fact, nearly all low drag designs that are practical utilize a long ogive and some kind of boattail. Ours used a nine-degree rebated boattail, and a 14-caliber radius curve that was offset by 0.014 inches from the tangent (a secant ogive, in other words). There is nothing magical about the numbers. There are dozens of variations which would work approximately as well, better in some guns, worse in others. | |||
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There is a problem with promoting these buzzword designs: people tend to believe that they solve all problems of accuracy, when in reality they are very special designs made for certain kinds of loads, rifling twist rates, and purposes. They are not always more accurate nor are they even useful in some guns. Here are some of the problems with the very low and ultra low drag designs (which means "high BC", the ballistic coefficient): To offer less air resistance, the bullet needs to be more streamlined, which in turn makes it longer for the same weight, or lighter for the same length as a conventional design. To keep the amount of shank in approximate balance with the extra long nose (which would fill up with all the available lead in a normal or light weight design and leave nothing for the shank), these bullets are usually made in the heavier weights for the caliber. This means that the long, heavy bullet has the center of balance shifted toward the rear, so it wants to turn over more easily than the conventional bullet, and thus requires a higher twist rate to stay nose first. If you have a barrel with the appropriate faster twist, you may get a flatter shooting bullet with equivalent accuracy to a normal design. Since the custom swaged bullets are usually made with more care than mass produced bullets, you may even get superior accuracy plus a flatter trajectory. But if you don't have a faster twist rate, you may find accuracy actually is worse than that of a shorter bullet having lower BC. The longer ogive and boattail (or rebated boattail) combine to make the same weight of bullet longer than in a conventional shape, which means that the bullet may not chamber or feed in some guns, and may actually be too long for the throat in the barrel. This might require setting the base of the bullet far down into the cartridge, intruding into the powder space, and possibly requiring the case neck to be partly encircling the start of the ogive. This means the bullet may not be held securely on a center line with the cartridge, but instead might be able to tip and start into the rifling at a slight angle, which does no good for accuracy. Bullet jackets need to be longer for the same weight, since the long thin nose doesn't hold as much volume (and thus weight) as a more rounded shape. And if you wish to make a light weight bullet, you'll need to use low density core material such as Corbin bullet balls, because if you fill the long ogive with lead, you'll need to at least balance the nose with a reasonable shank length. Having a long nose and balancing it with the shank means the minimum weight is higher than with a more rounded nose. In other words, you trade a somewhat flatter shooting bullet design for versatility in range of weight. A more traditional 6-S ogive or a round nosed shape will give you both heavier and lighter weight possibilities. On the other hand, extremely efficient airframes do give you a flatter shooting bullet, because they drop less in the same amount of flight time. While less trajectory isn't necessarily the same as more accuracy, it contributes to your ability to judge distance and hold the sights in the right place. It helps you be a better shooter, rather than actually improving the accuracy of the bullet, but the effect is the same. My point is that if you use accuracy and flat shooting as synonyms, you'll be just far enough off the mark so that you'll fall for some of the advertising hype about bullet shape. You may be like the fellow who heard that three of the top | |||
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benchrest shooters won that year using bullets that happened to have a 7-S ogive (a nose shape formed by a curve that has a radius of seven calibers) instead of the more common 6-S, so he passed up good buys on both 6-S and 8-S ogive die sets to wait for a custom made 7-S set. In truth, any of those sets would have been fine, and the 8-S would be slightly flatter shooting yet.
I'd like to let you in on another secret: there is no inherent difference in accuracy between spire points, truncated conical points, round noses, spitzers, and secant ogives, if you make all of them from equal quality materials with the same level of care. A round nose or what we would call a 3/4-E (elliptical ogive with a length of 0.75 times the caliber) handgun bullet is inherently no less accurate than the regular 9 or 10 degree truncated conical bullet (truncated means cut off, and the TC is a spire shape with the end cut off, usually at about 40% of the caliber). Whichever you like best and feeds best in your gun is the one to use. A common request is for dies to make a bullet with some arbitrary BC number, usually higher than anything else on the market from mass producers. But this is a little like spending all your money on a great set of magnesium wheels for your car, so you have nothing left for the engine or body work. Lots of teenagers did that when I was of that age. Today I hear the thumping of huge, overpowered speakers from expensive stereos coming from cars that could use a paint job and a tune-up, usually with the same genre of fuzzy-minded youthful driver who spent his burger-flipping paycheck for "cool mags" back in the `fifties. Putting all your attention on the ballistic coefficient and ignoring most of the other factors is very little different. The real goal is usually to hit the target at long range with greater reliability. Confusing the real goal with some narrow part of the total package that will get you there is a problem created by the myth that somehow, an arbitrary BC number bigger than anything available currently means the bullet will be more accurate. Sorry, but the BC is only a relative measure of inverse air resistance compared to some standard bullet, such as the one-inch artillery projectile that has been considered a 1.0 on the BC scale for decades. The BC means nothing by itself. You must also know the standard against which it is compared, and advertising sometimes plays on this fact to overstate the comparison or ratio by subtle use of a different standard projectile. For example, I could easily publish BC numbers of 2.50 or 3.59 or anything else I wanted, whereas most BC numbers are less than 1.0. How? By noting in the fine print, which no one reads, that the standard projectile used for comparison is a five grain wad of newspaper chewed to a soggy consistency and fired from a pursed pair of lips (yes, a spitball). More subtle yet, I could simply assume that everyone "knew" I was using a conventional 6-S 168 grain spitzer flat base bullet as my "standard", and then publish comparison BC numbers relating the bullets I was attempting to market to this standard. Not drawing any particular attention to the standard just reinforces the myth that BC has some independent value as a figure of merit. It is in fact a ratio, so it requires two items for comparison and has no meaning otherwise. Stating the BC alone is like saying the odds of the Atlanta Braves winning the next game against the Giants is "3". But three compared to what? You might assume 3 to 1. Maybe | |||
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the Giants fan meant 3 to 6, or 2 to 1 in favor of the Giants! Normally we would assume the other bullet in the implied BC figure is the old military standard one-inch projectile, but remember the old saying, "Assume makes an Ass of U and Me". Seeking a high BC is not a foolish quest, but it is foolish to think some number higher than that you read about a factory bullet will solve all your problems and improve the accuracy of your new bullet. How are you going to measure it? If you use the dual chronograph method, your measurements can be off by a very wide tolerance unless you fire a large number of rounds. Sometimes the variance is greater than the amount of supposed gain. The best way to achieve good accuracy is to judge it by the holes in the target. That is, use anything that improves the group and don't put on blinders in the quest for one specific part of the accuracy formula. High BC is desirable, but the higher spin rate it may require of the longer bullet can exaggerate normal eccentricities in the bullet, and wipe out any accuracy gains from a flatter trajectory. Each factor in the design of a bullet is part of an equation that tends to be self limiting: making any one factor too large automatically makes the others too small. You get the optimal performance by achieving the right balance of factors for your particular application, not by pushing one of them to the limit and ignoring the rest. The Myth of Critical DiameterThere can be a significant difference in accuracy between bullets of different diameter, but there is no cut and dried rule about it except that undersized bullets (compared to the rifling groove-to-groove depth of your particular gun, not to some arbitrary industry standard) generally don't shoot as well as bullets with a diameter at or slightly larger than the groove-to-groove depth. Oversized bullets tend to have minor problems in some guns with case swelling and chambering. The pressure difference is insignificant for a 0.308 inch bullet compared to a 0.309 inch bullet until you reach those loading intensities where the gun is about to come apart anyway. If it will feed and fit the chamber with the larger bullet seated in the case, it will probably shoot better than with a smaller bullet (if everything else is equal and the load is generally accurate and safe). For my money, if I were to decide on a given diameter for my swage dies, I would always choose either right on the money for diameter compared to my gun's rifling groove-to-groove depth, or slightly larger (between half and one thousandth, depending on whether it is an Auto-loader or not—some pistols have a problem with slightly larger bullets which bulge the case and cause feeding failures). On the other hand, if I had a bullet that shot well in a given gun, I couldn't care less if the bullet was undersized, lopsided and backward! The goal is to hit where you aim, and if the bullet does that, forget about what it ought to be and just be happy that it works so well. Some armchair ballisticians tend to wind themselves up so tightly in their theories that they miss the fun and the point of it all: shooting. If it works, it must be right by definition. | |||
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Many factory barrels of the same caliber are far different from each other in diameter. The differences in bore diameter at various points even in the same barrel can be far more than the wildest tolerances in any bullet. Since the whole idea of controlling bullet diameter and tolerance is to make it fit into the bore, or the rifling grooves, there's a problem here! Why worry about an overly precise bullet diameter if the bore isn't at least that precise? We've had clients send us sample bullets, pushed through a factory barrel, that came out as much as .41 caliber from a .40 caliber pistol! In one instance, the client sent the gun back twice and got two different oversized barrels, both different by as much as 0.005 inches from each other. I won't mention the gun-maker, but it is a respected name and the problem isn't unique. This doesn't mean that it isn't important to have good control over bullet diameter. It merely means that you should not take the "published specifications" for granted. Measure your gun if you really want to specify the bullet correctly to fit it. If you don't know how to measure it, you can fire a low velocity slug through it and capture the slug in water, and send us the slug to measure. By low velocity, I mean just enough pressure to get it out of the barrel reliably. Measuring a barrel is an art. Firing the bullet through it only gives you an idea of the diameter at the point where the bullet came out. Suppose your barrel has "waves" in the bore, where it varies 0.002 inches larger than the average, but the muzzle is actually tight at 0.001 smaller than the standard specifications. The bullet might expand when it passed through the big areas, but it would be drawn down again when it hit the tight spots. Which dimension is really the size of your bore? Who knows—it all depends on your meaning. Average? Mean? Tightest point? Loosest point? Standard deviation? You want a bullet to fit so it won't be distorted and so powder gas won't escape around it and cut the jacket or lead like a torch. It's worse to have gas jetting around the bullet in the loose places than it is to have the bullet slightly elongated by the tight ones (since the amount of distortion is so tiny, yet the damage by gas cutting can be so harmful to both bore and accuracy). That's why I lean toward large bullets so long as they don't cause any other problems. The fellow who says he must have a 0.2240-inch bullet for his .224 rifles could be right, if every one of them has a barrel with a .2240 maximum groove- to-groove diameter. But unless he actually knows that for a fact, he could be just as well off or perhaps better with a bullet from .2242 to .2245 diameter. The Myth of the Pressure RingYou've probably heard this one: a good accurate handmade bullet must have a pressure ring slightly larger than the rest of the shank, whereas a factory bullet doesn't have one and that is why factory bullets are less accurate. Lots of shooters believe this one. Actually, the pressure ring on the back end of a swaged bullet is there for two reasons. The difference in diameter between the core seating die, which is used to make the bullet expand to nearly final diameter in a cylinder form by pressing the | |||
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lead core into the undersized jacket, and the point forming die, which forms the ogive on the bullet, must be very small, but still the point forming die should be slightly larger than the core seating die (in diameter of hole). If the core seating die is the same size or larger, the bullet will tend to stick in the point forming die. People who don't know much about swaging will assume the point forming die is bad, when it is likely that the core seater is producing a bullet too large to easily slip into the hole of the point former. The difference is very small. A typical .224 bullet would be made using a core seating die of about 0.2238 inch diameter, or at least the bullet would come out of the core seater at that size (the hole might be slightly different because of material springback). A desirable range of diameters for a .224 bullet would be from 0.2240 to 0.2245 inches in the parallel shank section. Right at the base, the bullet might measure from 0.2242 to 0.2248. This "pressure ring" is the lack of springback across the solid disk of metal that makes the bullet base, compared to the springy tubular sides of the jacket. Having a large difference between core seater and point former die cavities will make the pressure ring larger, and if the difference gets too large, then the bullet will start to come out with a "wasp-waist" shape, like the old Herter "Super-Sonic Wasp-Waist" bullets of long ago. (A note about those Herter's bullets: these were most likely reject bullets made because of a severe mismatch in a set of commercial swage dies, but Herter's was innovative enough to turn someone else's rejects into their "Model Perfect" offering of the season. Strange advantages were touted for this bullet: it was said that the air went in a sort of circle around that hourglass shape and somehow whipped around behind the bullet, whacked it in the rear and drove it faster! If this were true, Herter's discovered a perpetual motion machine with a new twist. Imagine what would happen if you accidently gave one of those bullets a thump with your finger while it rested on the table: the air would start accelerating it faster and faster until it was zipping around the room at supersonic speed, blowing holes in all observed physics!) The pressure ring is not a design feature: it is a physical fact of life that gets in the way of having a nice parallel shank on the bullet and can expand the case neck as the bullet base passes through, leaving the bullet slightly loose. In a short-necked round like the .300 Savage, the pressure ring is a real problem, since the case holds part of the ring and part of the shank, and the bullet flops around as a result. Most of the time, the pressure ring doesn't hurt anything but if there were a way to get rid of it without hurting accuracy in some other way, it should be done. The best way to minimize it is to match the core seater and point former dies very closely, more closely than you can do with a regular micrometer. You can also make the bullets slightly oversized and tapered, so the dies really eject easily, and then push the bullet through a ring die that irons the sides perfectly straight: now you've got a factory bullet! That's the way it's done. But that also tends toward a loose fit between jacket and core: the core pushes in and stays there, while the jacket springs back a tiny bit and loosens its grip on the core. | |||
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If you bond the core (using Corbin Core Bond flux and melting the lead core into the jacket for a permanent adhesion), you can draw down the shank of the bullet without any springback effect. But all this is not necessary for target shooting and barely necessary for anything else so long as the ring is only slightly 0.001 inch or less) larger than the rest of the shank. If you have any problem with the bullet in a short necked case, then this is worth some consideration. The main thing is, don't be suckered into thinking that you must have this mysterious feature in order to have a top-quality benchrest bullet. It's just how they come out, no design required or intended, and rather than admit it, many bullet makers in the past have turned it into a "feature". This is rather like the software bug that the technical support person claims is actually a feature: it's supposed to work that way, didn't you know? (Good thing software companies don't design cars. Cars might have become 100 times cheaper and get 200 miles to the gallon if they followed the improvements made in computers, but I'm not sure I'd want to drive one that crashed four times a day!) The Myth of Copper FoulingHere's another myth that needs to be shot down: copper fouls your bore, and brass is too hard on it, so you have to use a mysterious metal called "gilding metal" that only the factories have. In the first place, gilding metal is 95% copper and 5% zinc, whereas the brass most people refer to is 70% copper and 30% zinc. Copper is normally 99.95% copper and a trace of silver or other elements, sometimes phosphorus, sometimes arsenic. You can have any of them for the going price, any time you like. Corbin stocks various kinds of bullet materials and can get others if you order the minimum run. Our jacket drawing equipment can use any of them (we may have to "tweak" it for a particular material, though). The factories normally use either gilding metal or commercial bronze for bullet jacket material. Commercial bronze is really not bronze at all. It is another kind of brass, made with 10% zinc and 90% copper. It is cheaper than gilding metal, slightly tougher and can be made harder. Any of these metals can be used to make good jackets. None of them necessarily has to foul the bore any more than the others. Pure copper, properly annealed, makes a fine jacket material but it is a little more "sticky" in the punch press dies and harder to draw to deep cups, so it is seldom used in high speed mass production. A little zinc makes the material easier to draw, but more brittle when it strikes the target. When it comes to a choice between helping the mass producer produce the product, or making the product work better for you, guess which way it goes! (To be fair, the price you pay is based on how fast the jacket can be produced and the price of the metal used, and the mass market is by definition interested in the best price.) Why do people think copper fouls more than gilding metal, then? I wondered about that for a long time, since we are involved with shooting lots of bullets made with copper and have not noticed any unusual fouling problems. (We get into all kinds of calibers, from .12 to 25mm. We've shot .50's made from everything you | |||
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can imagine, and fouling isn't any worse with copper.) I think a big part of it is the finish of the material used to make the bullets, and the treatment it gets during the process. Copper tubing is a traditional material for making bullets. It tends to have a slightly soft, powdery surface after it is annealed. Annealing with gas heat, or in an oxygen atmosphere, will oxidize the surface and cause a reddish or blackish oxide to form. These tend to be flaky and loose. When the copper is drawn down and shaped into a jacket, it will harden slightly but the surface may not be burnished enough to get rid of the porous layer. I think this layer is what comes off in the bores. Nearly all metals will leave something of themselves in the bore, but we are talking about fouling bad enough so that it is a problem, an exceptional amount of fouling. And with properly drawn and polished bullets, I have not seen any significant problem. With the highly finished copper strip that we use for making drawn bullet jackets, there is no problem worth consideration. Some of the rumor probably comes from the fact that people who do this sort of experimental work with bullets are more curious and inspect their guns more carefully than people who just buy factory bullets, and they notice even a small amount of fouling sooner. Some of it comes from the loose, porous finish that experimenters may get on their torch-annealed copper tubing jackets. So, use annealed copper instead of annealing it with a torch, or polish the jackets so that the outer surface is removed down to the hard underlying metal. Don't worry about it unless you actually experience a problem, which you probably won't. The Myth of Mysterious Rites of SwagingI've heard all these tales about how you have to let the bullets "rest" overnight before you shoot them, or how you have to swage cores and then put them in a jar and give them a day to "normalize" (whatever that means) before putting them into the jackets. Hardened lead alloys often change hardness over a period of time after having been subjected to stress, such as swaging, but if you are interested in accuracy you probably use pure lead wire (which has no such time-related hardness change). Most of this is purely in the mind of the person who believes it, and came about either because someone else said it, or because the person happened to shoot a great group one day after doing something of the kind and from that day forth will always give the ritual credit. I wonder if a hunter who dropped his rifle and had it go off and by sheer luck shot a deer with that stray bullet would henceforth go into the woods and toss his loaded rifle on a rock? I suppose we all know people who got lucky one time with totally inappropriate equipment or techniques, and without any further testing just assumed that the thing they did incorrectly was responsible for the good fortune of that day. Likewise, bad results are sometimes blamed on coincidental precursors. A statistic says that 80% of all people killed in car wrecks ate carrots during the previous | |||
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twelve months. So, does this mean that eating carrots causes you to get killed in a car crash? If you don't eat carrots, do you thus avoid such a fate? If you think so, maybe it is time for a refresher course in syllogisms. The Myth of Weight Tolerance Versus AccuracyOnce Friday I made a pile of bullets and wanted to shoot a good group so much that I spent all afternoon weighing and sorting them into two piles. The first pile had almost no weight variation that I could measure: they were right on. The other pile had the other bullets, which could vary as much as three grains plus or minus from my desired weight. After supper, I went back out to the bench and I carefully loaded cartridges for my heavy barrel .222 Remington on a nice Sako action, weighing every charge, and seating those bullets with the greatest of care. I was ready for Saturday's match. Saturday was a great success, and my group was as small as I could have hoped. I was now positive that absolute bullet weight control was the secret of small groups. Upon my triumphant return home, the first thing I noticed was the pile of bullets on my loading bench. It looked suspiciously small. Weighing a few, then a few more, it finally dawned upon me that I had loaded the rejects and shot them, instead of the selected ones. Come to think of it, there were a lot of loaded rounds! So I guess a six grain range of weight variation didn't make all that much difference in group size, after all. If a bullet is unbalanced, so that one side is heavier than the other, it will tend to spiral in flight and will land at different points around its axis of flight. That much is well proven and has been known for years. If the difference in weight between two bullets is caused by a bullet jacket that is thicker on one side (eccentric jacket walls) or if it is caused by an air pocket or void within the core of one bullet which is off-center, then the weight variation is a way of telling us about eccentric construction. Note that we don't know which of the two bullets is built incorrectly. With air pockets, the lighter bullet is probably the bad one, but with eccentric jacket walls, we don't really know if the heavy bullet has a thicker wall on one side, or if the lighter one has a thinner wall on one side. If the lighter bullet has a thinner wall but it is concentric, then provided we had five more like it, we could shoot just as good a group as we could with a concentric, thicker-wall jacket. If we had bullets with air pockets that were perfectly centered, such as you get with a hollow base or hollow point that is correctly swaged, then there is also no problem with eccentric weight or balance. Mixing bullets that have eccentric weight variations into a group that has none will increase the group size. Mixing thin walled concentric jackets with thicker ones can change the group size only because the friction of the jackets as they pass through the bore may be different, so the powder burns a little differently, and the velocity may vary. This can cause the bullets to drop more or less depending on their velocity. The variation due only to difference in weight, meaning the gravitational drop, is so slight at 100 yards on a few grains (such as 2% or so of | |||
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the bullet's weight) that you can disregard it. You may as well talk about the effects of an airplane flying over and its gravitational pull shifting the bullet impact as the weight variation in a 2% or less situation. If you make your own bullets, and you have jackets that not only weigh the same but have walls that are the same on all sides, and you seat the lead cores to the same pressure so there is no loose core and no air pockets, then you will be able to ignore weight variations of less than 1% of total weight for any kind of shooting, and below 2% for anything but top level benchrest competition. Any weight variation in this range would be simply more or less core, concentric to the bullet center line, and would have no serious or noticeable effect on group size. If you have the same weight variation and it can be shown that the cause is eccentric walls or anything else that causes the weight to be shifted in an eccentric manner, then you will probably notice an increase in group size. So, weight variation is not an absolute measure of quality, but it is an indicator of a possible problem. Eccentric bullets are easy to make by putting a known weight of nylon string down one side of the jacket before swaging in the core—you can control the weight and position of the variation this way. We find the groups of bullets made with concentric weight variation (more or less core weight) are within the average size for the control bullets, whereas the eccentrics tend to fall outside in proportion to the amount of eccentricity. My point is that weight is not some absolute number that tells you "good" or "bad" about a bullet. After all, a 2 grain plus or minus variation on a 50 grain .224 is plus or minus 4% of the total weight and may have some noticeable effect, whereas the same variation on a 500 grain .458 bullet is only 0.4% and is below the limit of accuracy of most electronic meters and chronographs, and is unlikely to have any affect that can be measured. Get out the instruction manual for any high precision digital scale, and you will probably find a "specifications" section that tells you the accuracy of the scale is from 1% to 5% of full scale reading, plus or minus the final digit. That is, if you are using a scale that goes to 500 grains, and the scale has an accuracy rating of 1% of full scale reading, that means the scale itself cannot tell the difference, reliably, between 495 and 505 grains! Not only that, but if the scale reads out to 0.01 grains, the last digit can be anything from 0 to 2 and still be within the range of accuracy guaranteed. Years ago, I established and ran a precision calibration laboratory as part of an electronics company that I had founded. We needed to certify accuracy of commercial and law enforcement radio transmitters to a certain accuracy, and sign our names to the tests on forms that would stand up in court in case of any problems with radio interference or licensing issues. Digital equipment was just starting to become affordable outside of the military, and we used the latest products from Hewlett-Packard and Tektronics, which were the best available. I was somewhat taken aback to learn that much cheaper equipment was advertised as having far greater precision, until I read the fine print and found that readout accuracy was being touted, not instrument precision. | |||
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Most people wouldn't know the difference, and would be fooled by this bit of deceptive advertising (which the major brands avoided). The digital readout is "accurate" to whatever last digit is offered, but connecting a readout with 0.0001 mile final digits to your car odometer cable certainly does not give you distance measuring to that fine level! All the tolerances and inaccuracies in turning the cable, sliding the tires, play in the gears, and so much more, would make that kind of readout accuracy a joke as far as precision of measurement. But it is still a good way for a company to sell cheap instruments to people who do not read the fine print! Even medium-priced digital micrometers sometimes tout read-out accuracy without mentioning actual instrument precision and repeatability. As a rule of thumb, strive for a maximum of 1% plus or minus weight variation in your best target bullets, and don't worry if you make hunting or defense bullets with a 2% variation. To get this figure, divide the difference between the heaviest bullet and the lightest bullet by the average bullet weight, and multiply by 100. The average bullet weight is the total of all weights divided by the number of bullets that you weighed. You can hold the tolerance to about 1/2% if you take extra care with consistent timing on the core swaging operation, and sort all your bullet jackets into similar weights before seating the cores. It only matters to the people who buy your bullets, because the one fairly accurate tool most handloaders own is a powder scale. No matter that it reads to about 1% of full scale, plus or minus. If your only tool is a hammer, every problem looks like a nail. If the only thing a person can measure with high accuracy is weight, then weight becomes the answer to every problem. Only, it isn't. At worst, it can be an indicator of other problems. The Myth of the Infallible MicrometerOne last example is the myth of the infallible micrometer. I think that at least once a month we hear from someone with the world's most accurate micrometer. That remarkable tool certainly gets around. Since the advent of digital electronic readouts of reasonable price, and the availability of micrometers and calipers with stated accuracy of either 0.0005 or 0.0001 inches (or sometimes 50 millionths, or whatever the ad writers feel like writing that week) there have been more than a few people who call to note that they expect to order a bullet that measures some ridiculously precise figure and wonder if we'll guarantee it. In the first place, Corbin makes the most precise bullet swages you can buy because we have put literally decades into building the only full-time, full-line bullet swaging equipment and die-works in the world, and you can't run one without the best measuring instruments. Each of our diamond lapping machines has a gauge mounted on it that cost several thousands of dollars, and is tested and set with a setting fixture that is periodically sent in for NBS calibration. The setting fixture alone costs more than most people would pay for their second car. The diamond probes that fit into the precision bore gauges cost several hundred dollars, and each one only covers a narrow range such as .204 to .210 inches, so we have thousands more in all these little diamond probe sets. | |||
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I am not reciting all this to impress anyone with what we spend on measuring tools, so much as to make this point: if there were anything better that was appropriate to this application, we'd buy it. That's our business. We have to know the limits and uses of precision measuring tools to survive. Those salesmen who call on Corbin certainly are more than anxious to sell us the latest and best technology, and they keep us appraised of it. Precision measurement isn't something we only read about in an old copy of Machine Tool magazine at the dentist's office. I also don't mean to imply that we know it all and no one could possibly measure anything better. I'm sure that at NASA or Sandia Labs or Cal-Tech there are tools of greater precision than we need or can afford. But what I do mean to point out is that someone with a digital micrometer that costs a hundred bucks or so isn't even close to the state of the art in measurement precision, and if this high priced equipment we use is only guaranteed to give plus or minus 50 millionths of an inch precision, you can darn well bet that the micrometer isn't going to actually give you anything like an absolute precision of plus or minus a half thousandth inch, which is 500 millionths. So, how can the ads in the machine tool catalogs say that the readout is accurate to 0.00001 inches or whatever they claim? Easy: they are talking about the readout. The digital readout is the thing that displays the numbers. If it says a given number, you can bet it means exactly that number, to the last digit it can display plus or minus one digit (since any digital tool has no finer division than 0 or 1 on its last number displayed, you never know for sure if the last number is half way between 0 and 1). But the trick—the secret, if you will—is in that wording. The readout accuracy has nothing to do with the instrument accuracy. You can connect a digital readout to anything, and the numbers will click off just fine, but they mean nothing more than the mechanical limit permitted by the actual instrument itself. Digital readout on a moderately priced instrument is a way to fool gullible buyers into thinking they bought the world's most accurate tool for a few dollars, while the "uninformed" laboratories continue to spend thousands to get the same kind of accuracy. It's the stuff headlines in supermarket checkout magazines are built from: "Man Survives Fall From Space Shuttle: Doctors Baffled". It's human nature to want to think that all the experts are wrong, because it gives the average fellow's ego a little boost. Sometimes the experts are wrong, of course, in some particular circumstance where their theory turned out to be off the mark. But, really, if it were possible to get dependable accuracy in the tenths of a thousandth inch with cheap tools, why would anyone in business waste money on anything else? I will never convince the person who is so proud of his new digital mike that he can't repeatedly and accurately tell what the diameter of a bullet is to five places, and probably not to four. The limit of accuracy of a lead-screw micrometer, which nearly all of them are unless you buy laser or magnetic track instruments (for thousands of dollars) is the physical accuracy of the mechanical screw thread itself, not the digital readout. This cannot honestly be guaranteed to be better than 0.0005 inches in the very finest of instruments, (such as the Starrett "Last Word" bench mike) and more likely is only accurate to 0.001 inches. Of | |||
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course they read to zillionths of an inch (well, at least 0.0001 inches) but being able to display a tiny number does not mean the tool really sees it repeatedly or even sees it at all. For all practical purposes, a micrometer you can hold in your hand will give you the nearest thousandth plus or minus about half a thousandth. So if you specify a bullet of 0.308 inches plus or minus 0.0005 inches, you have some chance of telling it is between 0.3085 and 0.3075 inches. If you buy a gauge block with guaranteed traceable dimension of 0.3080 inches plus or minus 0.0001 inches, you can set your mike as a comparator to see if your bullet is .3081 to .3079 inches. But you can't tell if you have a .30805 or a .30795 inch bullet. A screw thread measuring system just won't repeat any closer than that. All it can do is give you a readout where the numbers themselves are guaranteed to be whatever the ad says, not that they represent what the measured part actually is. That is how many precision tool brands are sold to the public today. The difference between readout and instrument precision is just complex enough so that some people don't care to understand it. It's much easier to believe you bought the precision of a $5,000 lab tool for $150. What matters is that the bullets land in the same hole, or as close to it as possible, and there is no way yet devised to determine if they will do that before shooting them! Bullets that are undersized to the bore by even half a thousandth may show signs of lower accuracy, whereas bullets that are a thousandth oversized from this ideal usually shoot as well as the "right" size bullet. But we don't really know in advance what is "right" because it depends on your particular barrel. We do know that in general, if you want maximum accuracy, you should strive for a tolerance range of minus zero, plus one thousandths of an inch from the groove-to-groove depth. You may not find this is "right" for every gun or load, but it is a good starting point. | |||
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4. Tubing JacketsBefore you can make a jacketed bullet, you need the jacket. The jacket wall thickness, length, and size determines the dimensions and sometimes even the number and type of other dies you will be using. The issue of what jacket you plan to use comes first, assuming you are using a jacket of course. Not all swaged bullets need a jacket. We will discuss paper-patched, lead, and other types later. You can buy some sizes and lengths of ready-made jackets (the cups or empty skins for the bullets). Corbin offers the high precision Versatile Benchrest VBTM jackets in popular rifle calibers, and nearly all standard calibers of handgun jackets. Bullet jackets are from .001 to .005 inches smaller than the caliber, so they can be expanded upward when you insert and seat the lead core. Because of the limited size of the market and the high cost of making and stocking good quality jackets, you can't always buy the calibers, lengths, and thicknesses you want to use. There are good alternatives to buying them. You can make your own, or you can buy something that is available and draw it down to make a smaller diameter, greater or less length (by pinch trimming), and thinner or thicker wall (by design of the punch to die clearance). Commercially made bullet jackets normally contain from 5% to 10% zinc, with the balance of the alloy being copper. The 5% zinc alloy is called "gilding metal", and the 10% zinc alloy is called "commercial bronze", even though it isn't a bronze at all (bronzes are tin-copper alloys). The advantage of the zinc is that it makes the jackets easier to draw into deep tubes, starting with flat strip, without breaking through at the end or wrinkling. But for shooting purposes, pure copper tends to hold together better on impact and has about the same level of fouling if the surface finish is equally good. Corbin makes two different systems to form your own bullet jackets, one system using tubing, and one using flat strip. Tubing dies cost less and fit more kinds of presses, but strip jackets have the accuracy edge and can be made with greater control over the wall tapers and thickness. Corbin offers deep-drawing grade copper strip in 5-pound bundles of cut sections (typically 2-foot pieces), and in 50-pound pancake coils with a 16-inch center, which fit on our automatic uncoiler for automatic feeding. We also offer supplies of copper tubing in 1/4-inch, 5/16- inch, 3/8-inch, and 1/2-inch diameter from stock, and nearly any diameter on special order. All calibers from .224 to .512 can be made with the stock sizes. Jacketed shotgun slugs can be made with 3/4-inch tubing, and 1-inch Gatling or 4-bore (.998) bullets can be made with 1-inch tubing. We do not stock these larger sizes but by the time the dies are ready, we would have a special order ready for you. For big game hunting, the tubing jacket may have the edge since it is easier to build thicker walled, tougher jackets with tubing (after all, the deep drawing operation is done for you in tubing and all you have to do is round over one end and adjust the diameter in a draw die). Jacket drawing from strip can be done easily in a hand press only for the shorter jacket lengths, because punching out a disk and | |||
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turning it into a cup requires a lot of power early in the stroke. Hand presses generate almost all their power at the end of the stroke. Hydraulic presses are used for rifle jacket lengths, in order to get full power at the start of the stroke. Copper Tubing Jacket Maker Sets (CTJM-1-S, and -H)You can make jackets from copper tubing (or almost any other metal, but copper, aluminum, brass, and mild steel are the most practical things to use, and of these, copper works best for most shooting needs). To do this, you could use copper water tubing (yes, the same kind used to hook up wash basins), boiler tubing, or refrigeration tubing. Corbin has precision drawing grade tubing available also, if you want "good stuff" for testing. The cost of new tubing generally means that you won't save money over buying jackets if the jacket you want is already available on the market. But most large caliber jackets for rifles, or heavy walled jackets of any sort, are simply not available unless you make them, so the cost of the jacket is secondary to whether or not you want a better bullet! If you can get a reasonably good quality surplus tubing from contractors or plumbers, and the wall thickness variation is not too great, construction sites and contractors might be a low-cost source. Regardless of the size or type, you would cut the tubing to length, deburr one end, put the piece over a precision punch and round the end over in the proper diameter end-rounding die (looks like a blunt point forming die), anneal the tube, draw it to smaller diameter, and then flatten the end with a special punch in your normal core seat die. All the tools you need to form the cut tubing pieces are included in the CTJM-1 tubing jacket maker, with the exception of the tubing saw to cut the tubing to length, and the proper core seating die to flatten the end of the tubing (or to form the boattail base). The core seating die (or boattail base former die) is part of the bullet swage set, so it is normally assumed that you have this die already. If you only want to make the jackets, and do not have the bullet swage die, tell us so that we can recommend the proper die to finish the jacket and add this to your package. Generally, if you want to make a tubing jacket it is because you also want to make the bullet. It would be redundant to charge you for two of the same dies, one to complete the base and the same one again to seat the lead core. But sometimes a person only wishes to make and sell jackets, not finished bullets. If this is the case, we need to know it. You can't finish the jacket without one of the dies used in the normal bullet swaging set, and that die is not normally included in the CTJM-1 set. The tubing jacket maker set will include whatever additional components are needed in order to seat the core into the jacket. For example, if you order the tubing jacket maker for .458 caliber, we will provide a proper size core seating punch to fit the jacket for a given weight of flat base bullet. However, if you plan to make a rebated boattail bullet, you might need to purchase one additional punch, an adjustable length core seating punch. This is a shouldered punch, which presses against the end of a given length of jacket and keeps it from extruding forward while the lead is being seated. Sometimes a RBT design will cause the | |||
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copper tubing to extrude forward, which not only elongates the jacket but stretches and thins it at the base, where it may separate within the die. Using the adjustable length core seating punch holds the jacket in place and prevents this from happening. Tubing Jacket Advantages Over Drawn JacketsThe advantages are (1) the tooling is lower cost, (2) the number of operations is relatively small and easy to learn, (3) tubing is fairly low cost in modest quantities compared to buying large rolls of strip material, and (4) the process makes excellent bullets for big game shooting. In a Corbin hydraulic-powered press such as the CHP-1 Hydro-press, or CSP-2H Hydro Junior, using the H family of high pressure dies, you can completely close the base so no hole appears. In the -S family of hand press dies, which fit the Corbin S-Press CSP-1, or when using an -H die in the Mega-Mite CSP-2 hand press, you usually cannot generate enough pressure to completely close the base, so a tiny hole remains, but it is far smaller than most military open base bullets and causes no problem. Tubing jackets are not just pieces of tube shaped into a bullet: they are almost identical to a normal closed-base jacket. Generally, they have thicker walls with no taper toward the front. You can make almost any reasonable length and wall thickness, if you use the correct press and dies. In each diameter, we stock one wall thickness, which varies with the diameter from .028 to .035-inch. Tubing jackets are most often used with hunting bullet designs, and nearly all commercial bullet makers today use Corbin Core Bond to create a bullet that will not shed its core, and can be shot "inside out" without losing much of its total weight. Core Bond is inexpensive, fast, and works much better in actual big game hunting than a partitioned design. The entire core is secured to the jacket, rather than just protecting half of the core. In my eclectic bullet collection, I have a bonded tubing jacket bullet that William McBride (founder of Star Custom Bullets) brought back from South Africa. It had been shot at a charging Cape Buffalo's head, penetrating the thick horn and skull (probably more than six inches of solid horn and bone). It killed the animal with this difficult brain shot, and the 0.065-inch thick brass jacket was turned inside out from the impact but still retained nearly 100% of the bonded lead core. He also brought me a full metal jacket military bullet that was formed into a U-shape from being shot into a Cape Buffalo. The bullet came back out the same side. Either it or another one like it struck one of the South African professional hunters in the leg (and in typical fashion, the jolly fellow insisted on stopping at a bar before going to the hospital!). I have dozens of other examples of amazing and possibly lifesaving performances from bonded core bullets using our Core Bond process, compared with other designs which failed. There is no doubt in my mind that, given the choice, every bullet I fired at a dangerous game animal would be a bonded core design. | |||
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Disadvantages of tubing jackets:1. The walls are straight, rather than tapered, so that without special operations the jacket will not be the "controlled expansion" type. 2. Tubing jackets larger than .257 caliber generally are not practical to make below .030 wall thickness (sometimes you can get .025 wall tubing, but it is harder to find and doesn't always form, in every caliber or shape, without buckling). 3. It is not practical to build precision benchrest grade bullets using readily available tubing. This is not to say tubing jackets are "inaccurate", but only that a deep drawn jacket can be made with closer tolerances given the materials available on the market today. Tubing jacket bullets can, and have, set match records. But they probably will never set high level competitive benchrest records. On the other hand, they certainly do bring home a lot of big game every year where the thinner and more brittle drawn jackets fail and let it get away! 4. Tubing jacket makers do not lend themselves to automatic production as easily as strip jacket makers. The initial step in making a tubing jacket is to cut a piece of tubing to a specific length. From this point on, it is handled as an individual component. Strip can be fed into a stacked or progressive die system that allows some of the operations to be done to the jacket in a continuous feed procedure, as the strip itself provides some of the conveyance of the forming jacket. On the other hand, there are less steps involved in making tubing jackets than in forming strip into a jacket. Copper Tubing Jacket Maker sets:The CTJM-1-S (Copper Tubing Jacket Maker, type -S) uses 1-inch diameter dies, and fits the S-Press (CSP-1) or the CSP-1H Hydro-Mite. This set can make jackets up to 1.3 inches long, although you must move the punch holder back and forth to load longer pieces and form them, or use the optional FPH-QC-S quick change punch holder. The wall thickness is limited to 0.035 inches (the standard type L copper tubing normally has 0.028 to .035 inch thick walls). Only "pure" (not alloyed or brass) copper tubing is recommended. Jackets can be made in .22 to .458 caliber in this die family. In theory, you could also make smaller calibers from tubing, but it is cheaper and easier to make them from fired .22 cases. At this time, tubing is available from over 200 primary sources in the USA alone, but almost all the available sizes are 1/2 inch, 3/8 inch, 5/16 inch and 1/4 inch O.D. without paying for custom drawn production runs. These can be used to make all calibers in the range mentioned The CTJM-1-H (Copper Tubing Jacket Maker, type -H) uses 1.5 inch diameter dies, and fits the CSP-2 Mega-Mite press, the CSP-2H Hydro Junior, and the CHP1 Corbin Hydro-Press. There is almost no limit to the kind, thickness, and length of material you can form in these dies. Mild steel, copper, brass, aluminum—all are candidates for a set of tooling to make good jackets. However, you cannot interchange them with abandon. A set of dies developed for the characteristics of one metal, one wall thickness and diameter of tubing will not necessarily work with different material or dimensions. | |||
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You can order tubing made from nearly any material, but unless it is commonly available from the mills, and stocked by the distributors, you may pay a hefty premium for the use of such materials. Corbin stocks copper tubing in the proper grades, tolerances, anneals, and diameters to make nearly any caliber within our standard range. Unless you really have a strong desire to dive into deeper waters, and do not mind that it will cost extra for both the material and possibly for the development of correct dimensioned tooling that is nonstandard, it is best to stay with proven materials and dimensions. Changing jacket lengths:You can change the length of a tubing jacket, if you also purchase an additional punch per length. The end rounding punch has a turned-down section that is just shorter than the desired length by half the diameter of the tubing, so that enough metal protrudes to be rolled over into a base within the first die. Normally you can use the same end flattening punch for a modest change in length, if it is longer than the punch tip. The whole idea of these punches is that enough unsupported tubing projects past their end to roll over into an angle or curve (in the end rounding die) and then flatten by pressing firmly in the core seating die (without a core). If your jacket projects a little more past the end than the sample sent with the punch, it will probably work anyway, until it gets long enough so that a lot of jacket is unsupported and collapses inward on itself when you try to round the open end. But if the jacket is even a little too short, the punch will come up against the end of the die and there won't be any jacket there to be rounded. Thus, you have wider base openings, incomplete closures, and might even damage the die or punch trying to get the base to close up. The right length to cut the piece of tubing is marked on the side of the end-rounding punch. You want the cut tube to rest on the punch shoulder, be supported by the reduced diameter tip up to about half a caliber that projects beyond the punch end. You are going to fold half a caliber per side to close up the base. The length of the cut tubing is critical to within about 0.01 inches for a given punch. An alternative to buying specific length end-rounding punches is to purchase one adjustable length punch. The adjustable length punches can be set so that the shoulder section moves, like the barrel of a micrometer, and allows more or less of the tip to project beyond it. The pressure is tremendous, stress on the parts is high, and the punch has to be made very strong if it is to last. An adjustable punch will cost more than a solid one-piece punch. The cost advantage is twofold. First, if you want three or more lengths of tubing, the adjustable punch will usually pay for itself over buying individual punches. Second, if you don't know for sure what length you want, but only have a rough idea based on approximate weight and amount of exposed lead or open tip, then the adjustable punch avoids mistakes and lets you use whatever length eventually proves to be best for your ideas and weights of bullet. | |||
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Changing Tubing Dimensions:A CTJM-1 tubing jacket maker set is designed for a specific diameter and wall thickness of tubing. The length is easy to adjust by using different end rounding punches (within reason). The actual tubing diameter controls the size of the dies, and the wall thickness of that diameter of tubing controls the diameter of the punches. Therefore, changing tubing diameter means getting a different tubing jacket maker set, and changing the wall thickness means changing the punches with possible exception of the punch that draws down the jacket to actual caliber requirement (sometimes this punch will work with thinner walls than the original jacket design). Note also that if you change the diameter of tubing, or the wall thickness, you will probably need different components from the separate bullet swage set. The core swage die accepts a specific size of lead wire and expands it so it fits properly into a given jacket. If you change the jacket internal diameter, the same core may no longer fit inside. This would mean getting a different core swage die. If the wire that you used before is now too large to fit the new core swage die, then you will also need to obtain smaller wire diameter. Also, the core seating punch probably will not fit a different diameter of jacket I.D. since it must be a pressure-sealing fit to the jacket. Changing wall thickness almost always requires a new core seating punch for the core seat die. You can see that going from a .030 to a .050 jacket wall thickness could require different lead wire, different core swaging die, and different core seating punch. Going the other direction, you may be able to get by with just a larger diameter core seating punch, because the smaller core probably will still fit into the jacket well enough. If, on the other hand, you were to change jacket materials from a .050 to a .030 wall thickness, there is no doubt you would need new smaller diameter lead wire, core swage die, and core seating punch, in addition to the end rounding punch, jacket drawing punch, and end flattening punch. If you have multiple lengths or adjustable length punches for the .050 tubing, you may wish to replace them all to have the same length capabilities for the new .030 tubing. In order to build the new components, we will need the entire set here. This is especially true if you obtain your own tubing, since it may react differently than ours to the same pressures and dimensions of tooling. A development fee usually applies because of the amount of time it takes to build and test different punch diameters and to develop the information we need with tubing different from that we have thoroughly examined for years. Normally this is two hours at current shop rate. The two most common problems clients have using tubing jacket makers is failure to use the same material that was used to design the tools, and failure to follow directions about length and annealing steps. The problems often show up further down the processing line, instead of immediately (at least to the inexperienced jacket maker). Bullets may stick in the point forming die, and the bullet maker is ready to condemn the swage die when in reality the entire problem is a skipped annealing step when the jacket was being formed. Jackets may wrinkle, | |||
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deform, crack at the base, or stick fast to the end flattening punch, and the problem is simply that the operator believes his tubing, obtained locally, is equivalent to the tubing used to develop the die set when it is far different in some respect. Even if the dimensions are the same, the hardness or grain structure of the metal may be different enough to cause problems during precision redrawing and base forming. When we build a jacket maker set, it is best if we start with the material you plan to use. If you change materials, we can add punches (so you build a wider range of working supplies) or modify your existing punches (probably not as cost effective, since it takes close to the same labor cost to change them as it does to make new ones). Selecting the right tubing:The standard sizes of tubing that are available, and which we stock for resale, are 1/2 inch O.D., 3/8 inch O.D., 5/16 inch O.D., and 1/4 inch O.D. We can also make custom diameters. They are more expensive than the standard sizes but we can draw them for you. The wall thicknesses are normally .028 or .035 depending on the diameter and standard tubing industry practice. We can obtain .050 and .065 or close to these diameters in the 3/8 and 1/2 inch sizes, on special order. We can also custom order anything you want that a copper tubing mill will make, but it may be subject to minimum quantity and must be prepaid. You are probably well advised to buy it for yourself and make your own best deal, then send us sample material to build the tools, once you step outside of the sizes and thicknesses that are popular enough for us to stock. I'll be glad to act as a buyer agent for you, but judging from past experience, a person who hasn't been shopping for custom tubing tends to rapidly change from vertical to horizontal orientation upon learning the price... and it is less stressful for me to be the one hearing about it from you, than conversely. All that having been said, people do buy custom tubing now and then, and although it is normally higher than what we stock, if it does the job better than anything else, and you are satisfied with the performance (or can sell the bullets for a reasonable profit) then obviously the tubing price isn't too much. In each caliber, the closest larger diameter of tubing is selected as the starting point. The 1/2 inch tubing is used to make all calibers from .512 down to just above .375 (for instance, the .400 caliber). Both rifle and handgun calibers can be made, although you need end rounding punches for each length. The first step, rounding the tubing end, is the same for all of the calibers that a given diameter of tubing can make. It uses the same end rounding die. For example, if you wanted to make both a .458 rifle jacket and a .429 pistol jacket, you could start with exactly the same .458 CTJM-1 die set, because both of them use 1/2 inch diameter tubing. You would need two different end rounding punches, assuming the .429 was a short pistol jacket and the .458 was a longer rifle jacket. Otherwise, if the length is the same, and you are using the same diameter and wall thickness of tubing, then the same end rounding die and punch can be used for both. | |||
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If you plan to get your own tubing somewhere else, we must have at least six feet of it on hand before we can start your order. We will cut it into pieces and test the tooling. The length and diameter, whether the tubing sticks or releases from the punches, the concentricity and evenness all depend on the temper, grain, alloy, tolerances, wall thickness, and diameter of your tubing. Plumbing is not especially precise in these factors. If you get a large quantity at one time, it will probably be consistent enough to make good bullets, but if you change suppliers there is no guarantee that the same nominal sizes you get will be anywhere near identical. The jacket maker punches may need some adjustment, or different punches need to be made, in case you change vendors or your vendor changes specifications. Corbin's tubing is higher cost than some of the tubing you will find in the hardware stores, but not by a great deal. We are very strict with our specifications and order large lots of high quality tubing just for bullet making. We recommend that, unless you have a good source of tubing in mind, you use our standard tubing to get started. We can help you obtain larger quantities when your needs outgrow a few dozen feet at a time, but until then, the odds are good that you won't find much better pricing. My recommendation is that you establish prices for your custom bullets that allow you to make a profit even with the higher cost material, purchased initially in small quantity. Then, by the time you can afford the larger mill orders, you'll have already guaranteed a higher margin and your success will be just that much greater. The range of calibers for each size of tubing
To cut copper tubing cleanly and accurately, at a good production rate, Corbin builds a power tubing cutter saw (SAW-1). We also make a version for continuous lengths (no limit to the cut length on either side of the blade) called the SAW-2. A standard, roll-type tubing cutter usually rolls the end so much it won't fit over a punch. You can also use either a lathe, or a metal cutting blade in a saw. Some of the more successful methods include a fine tooth metal cutting blade in a chop saw, table saw, miter box saw, jig saw, or band saw. A home-built stop, consisting of nothing more elaborate than a block of wood clamped to the saw table, will give | |||
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you reasonably accurate lengths. The number of teeth per inch should be from 32 to 40 on a hacksaw blade. The rule of thumb is "three teeth in the material at all times". Copper is a little "sticky" so you may wish to use a blade with a special tooth set or with a reverse rake on the teeth. There are some low cost modified circular chop saws available that are supposed to be made for tubing, but I have tried them and they leave much to be desired from the standpoint of precision, clean cut, or safety. If I thought they were any good, I would simply buy and resell them rather than build our own. To get a good clean cut without vibration and burning, we use a high speed steel blade that has been cyrogenically treated and dry film lube coated. The blades have a rake that lets them cut copper smoothly, and no set to the teeth so you get a minimum amount of waste with each cut. To reduce the risk of kickback and for other safety concerns, we use a 3-inch diameter blade and secure it to a ball bearing shaft supported at both ends, driven by a toothed rubber drive belt, in the manner of a tool post grinder. The precision spindle assembly reduces wobble and drift to nearly zero. On the continuous length model, we use two such spindles so the tubing can clear the drive assembly and be infinitely long. On the standard bullet-makers' model, you can cut up to about 3 inch long pieces, more than sufficient for any reasonable bullet that doesn't require a mobile platform gun! We also have tubing in 2 foot lengths, easy to mail or ship anywhere in the world. You can save some labor cost by chopping these up yourself. Tubing normally comes in either 20 foot pieces in big boxes of 200 to 500 pounds each, or in coils (annealed tubing). We use hard drawn or 3/4-hard, as it is called, because it is easy to handle in a lathe for cutting. How to make tubing jackets:First, you cut a supply of tubing to the length specified on the end rounding punch. If it says "1-1/4" on the side of the punch, that is the length to cut the tubing. It will make shorter jackets because the end will be rolled over. But it may also become longer in the process of drawing down to size, so you can't really tell exactly how long the jacket will be until you have made a few with a given material.
Step 1, End Rounding: Make sure the cut tubes will slip over the end rounding punch. They may fit snugly, but if they can't be forced on by hand, it is probably due to a burr or rolled edge from the cutting operation. This will need to be removed using a countersink or a chamfering tool. Jackets cut with the SAW-1 normally are burr-free unless the blade has become worn out. (Blade life can be greatly extended by making sure a light oil or tool coolant is used on the felt pad that rubs the sides of the blade, inside the guard, and is frequently refreshed). To round the end of the tubing, first install the die marked "J" (for jacket making die) in the ram of your press. This die has an ejection punch, similar to a point forming die. It fact, it is a modified version of a point forming die. The | |||
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internal punch needs to be "trapped" by the stop pin in the S-Press. To easily do this, remove the internal punch from the die and grasp it by the tip of the ejection pin. Hold the punch so that you can see about how far down the hole or slot in the punch head has to be, within the ram, in order to put the stop pin into it. (Older -M type dies have a slotted punch that uses the short stop pin, current dies use a hole through the punch and a long stop pin.) I like to hold the pin between my thumb and forefinger on the outside of the press, and slide it so that the hole in the head lines up with the stop pin with my finger tips just level with the top of the ram. Then without changing my grip, I move the pin into the ram, lower it until my fingertip touches the ram top, and insert the stop pin. With very little jiggling up and down or turning, I can always get the stop pin to pass through the hole this way. If the internal punch (or, if you prefer, ejection pin punch) is secured, you can pull it and it won't come out of the press ram. Now, align the hole in the threaded end of the die with the punch tip, slide the die down, and screw it into the ram. The punch is now centered by the hole in the die, and is secure within the ram by means of the stop pin. Insert the external end rounding punch into the punch holder in the top of the press. If you are using the -H dies and larger presses, then a retraction pin goes through the hole in the punch, and the knockout bar goes under the punch head, through the slot in the ram. All swage dies (not draw dies) work this way. Some do not require the retraction pin, but the end rounding die does. Lubricate the inside of the jacket with a swab, using Corbin Swage Lube. Wipe a little of the same lube on the outside. You can use your fingertips for this. The amount isn't critical, as long as you have some present. Some people lubricate the outside of the top punch (the external punch). This really isn't as good. When you push the tube over the punch, the snug fit probably will shove all the lube up and fail to get inside the tube at all. Then the tube may try to stick on the punch. A swab saturated with swage lube is a quick and easy way to get plenty of lube inside the tube, where it will do some good. Adjust the floating punch holder so that the punch is rather high in the press, and allows the ram to go all the way up without any contact inside the die. With the ram all the way up, lower the punch holder until you can't turn it by hand because the jacket is against the end of the die cavity. Lower the ram slightly, and give the punch holder a slight turn, perhaps a quarter to an eighth of a rotation, toward the die. Then raise the ram. Repeat this adjustment process until you feel some resistance. Lower the die and inspect the jacket. You have gone far enough when the end of the jacket is rolled over so it makes a hole slightly smaller than the diameter of the ejection punch. If there is enough length to the jacket, it will be possible to just start to form a little "pipe" on the end of the jacket, where the jacket tries to go up the ejection pin hole. That is nearly perfect adjustment. Lower the ram, and you should be able to turn the jacket by hand and slide it off the punch. If it sticks on the punch and cannot be removed with only mild force, by hand, then it means the tubing wall is too thick for the punch diameter or you did not lubricate the tube properly. The latter is easy to fix, the former means you need a different punch or different jacket material. | |||
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Step 2, Annealing: You must anneal the tubing jacket after you have formed the rounded end and before drawing it down to correct diameter. If you fail to heat the jacket red hot and let it cool (annealing it), then you will have problems with cracking, sticking on punches, uneven or difficult forming. A regular propane torch is all it takes. Just sit a few jackets on a couple of fire bricks, arranged in an "L" shape so the flame is reflected back, and heat them by playing the flame directly on the jackets, one by one. Corbin offers a ceramic block "kit" for heat treating and annealing, consisting of two low thermal density ceramic blocks and a template for drilling a pattern of 32 holes, to support the tubing jackets for annealing and for bonding cores. The soft ceramic material is easy to drill with a pocket knife or a wood bit (not a new one unless you plan to resharpen it). One block can be used as a reflector to direct heat to the opposite side of the jackets. All it takes is a few seconds to heat them and let them cool for a few minutes before further handling. A great many of the problems that some bullet makers have with tubing jackets and bullets comes from skipping the annealing stage. For whatever reason—maybe because it takes extra work—they assume the step is unnecessary. Wrong! Skip it and you will have problems with tubing that sticks in the dies or on the punches, bullets coming out the wrong diameter, or bullets that come out the wrong length! Maybe you will get away without annealing in some rare case, but by and large, it is a required step that affects the rest of the operation severely if skipped. We also offer electronic-control, electric heating furnaces with digital readout. The HTO2 Heat Treatment Oven runs on 120 volts or, optionally, 240 volts, and can safely generate 2000 degrees F. and hold the temperature within a few degrees. All you need to anneal the tubing is about 1400 degrees F. for a few seconds. Just a visible red glow is enough. No need to keep it hot past that. You must anneal before attempting to draw down the jacket material. The only exception to this is with rimfire jacket cases, because of the head unfolding. In this case only, you must anneal after drawing, never before drawing. Annealing a rimfire jacket before drawing it can cause the drawing punches to break, if the soft thin jacket tries to bunch up around the punch. But copper tubing is tough and thick, and needs to be annealed before you do any more to it so it won't become too brittle. I thought I should mention this exception, so you don't get confused later when we reverse this procedure in making free jackets from fired .22 cases. Softened copper tubing expands better and generally is less likely to fragment on impact. It also picks up a scale that comes off in the bore, unless you tumble or vibrate the bullets in a polishing media to remove it. This scale may be what causes some kinds of custom bullets to "foul" worse than a gilding metal jacket. To eliminate this soft surface scaling or powdery finish on the tubing jacket, we make the BPK-1 Bullet Polisher Kit. It is a kit consisting of a vibrator motor prewired with thermal cutout, line cord and switch, a mounting bracket and anti-vibration hardware, instructions and a package of polishing media. Mounting this motor to the bottom of a coffee can or bucket is the usual procedure, with the | |||
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container suspended from a shelf bracket or a door spring hooked to some kind of hanger. Vibratory polishers tend to move the media around and carry the bullets in it, instead of rolling the bullets against each other. You do not need to polish the jackets yet. Wait until they are finished. When you do polish them, it is best to use walnut shell without any additional abrasive. Abrasives used to polish bullets will embed themselves in the surface of the jacket, and be carried to the bore, where they tend to "lap" the bore and thus cause unnecessary wear on the rifling. Lapping is not always desirable! Once the bore surface has been polished, further lapping is just wearing it out. I mention this because some people have suggested that abrasives embedded in bullets could be used as "fire lapping" treatment. Great idea, but wait until I start selling replacement barrels before you try it! It's a little like saying "If a little wear is good, a lot of wear is better!" Better for the guy waiting to sell you another barrel, that is. Lapping is just controlled wearing away of the high points. Tooling chatter makes high points and low points, and lapping wears away the high points so they come closer to matching the low points. But rifling is the ultimate high point in your bore, and continued lapping is just wearing that away until it matches the groove depth and you have a somewhat larger bore shotgun. Geeez...you'd think this was obvious but believe me, not everyone gets it. Where was I? Oh, yeah, I was getting to the point of copper tubing bullets and fouling. It bears repeating, since I probably mentioned it in other places: copper tubing doesn't foul your bore any worse than factory bullets, unless the material was left in a poor surface condition. Now, I know, you have probably used tubing jacketed bullets before, and maybe you got some that had not been burnished or polished correctly (or at all). These bullets probably did leave some excess copper wash. So the end result is that you may have equated copper jackets with fouling. But it doesn't have to be that way. Just polish them with walnut shell or other non-embedding media (corncobs will work, much more slowly than walnut). This removes the loose, flaky surface finish, and gets you down to the work-hardened surface. It glides along on top of the rifling just fine, and leaves no more of itself behind than any decently finished gilding metal jacket.
Step 3. Drawing to Size: You now have a tubing-diameter "jacket" with one end rounded over but not flattened. The next step is to draw this original diameter jacket down to a size that fits into the core seating die. For this, a punch is used which screws into the press ram, instead of into the floating punch holder. The punch holder is removed from the press, and instead the JRD-1 jacket draw die is installed. In a hand press, this die is set relatively high, engaging at least two or more threads fully, but set to use the maximum leverage at the end of the stroke just as the jacket clears the constriction of the die. In a power press, this isn't so important, because there is full power all through the stroke. | |||
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In the S-Press, it is generally desirable to change the stroke into the long mode (move the pin that fastens the ram to the toggle arms so it moves in the widest arc). Be certain to remove the Stop Pin, in the front of the press, or else you will not be able to use the full stroke and may possibly shear off the stop pin if you try hard enough! The stop pin is only used for bullet swaging, in the short stroke. If you do not use the long stroke, you may not have enough ram travel to push the jacket through the draw die, or even to load another jacket onto the punch. With jacket drawing, you may or may not have to put any more lube inside the jacket. Play it by ear unless the instructions that come with the set say otherwise. If the jackets stick on the punch, lube them inside with a swab. But otherwise, skip it. It is a good idea to wipe a little lube on the outside of the jacket, since this part of the material will be in heavy contact with the die. Slip the jacket over the end of the punch, with the ram all the way down. Raise the ram and push the jacket through the die. If it doesn't pop out the top, use the next one to push it out. But generally, it is best to get out jacket all the way "free" even it if is still sitting in the top of the die. Drawing punches are somewhat long and of small diameter, so try not to ever side-load them by cocking the jacket sideways or running the jacket into the die face instead of into the hole. These things would be a result of hurrying too fast and not paying attention to the alignment. Drawing is straightforward: in the bottom, and out the top. The jacket should be easy to remove from the punch after drawing. If the jacket is reduced too much for the punch, it will pinch the punch and may pull the punch apart on the down stroke. This would be a matter of possibly selecting the wrong punch when you have several that look similar, or using a jacket with walls that are too thick... assuming of course that the die and punch and jacket combination worked when it was tested and shipped. Change any of the three, and it might not work. The jacket drawing step is the first point where you can add more calibers to an existing die set. There are two ways to do this. First, you can change the draw die, and get a different end flattening punch as well, and then use the reduced jacket in the new caliber core seating die. This method is the most likely to always work with all calibers. The second way is to go ahead and finish the jacket at the larger caliber, for which the set was built, and then draw down the finished jacket. This method still requires a draw die (with different dimensions) but does not require a new end flattening punch. And usually it works. But sometimes the base tries to unfold when a tubing jacket is drawn down too far, because the punch diameter supports only a small part of the jacket base while pushing against the resistance of the reducing die. (Someone in the back row yells out "Well, make the punch bigger!" about now, forgetting that the punch has to fit easily inside the jacket after it has been reduced, and thus if the difference in reduction is great, the punch will be relatively small...or else, relatively stuck! Never mind: he works for the government.) Within the normal range for a given diameter of tubing, you can simply add a JRD-1 jacket reducing die for the tubing, and a matching End Flattening ("E") die for your existing core seater die, and turn a CTJM-1 set into a different caliber, either smaller or larger than the original design. In some cases, you can finish the | |||
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jacket and then draw it to a smaller size (not larger) with a JRD-1. When deciding which way to go, it is wise to figure on the first method. Sometimes we can get the second way to work reliably, but not always.
Step 4. Finish the Base: Now you have a round-ended jacket, annealed, and drawn to the correct diameter to fit within a core seating die (or the BT-1 boattail forming die). The final step is to finish the base, either making it flat, or shaping it into a rebated boattail. The punch marked "E" is similar in appearance to the "J" punch (jacket maker or end rounding punch). It has a reduced diameter section from the tip back to a shoulder. However, it has a smaller diameter in both sections than the "J" punch. The end flattening punch presses against the base of the copper tube jacket, from the inside, and forces it against the internal core seat punch within the core seating die, flattening the base between the two punches. Or, in the case of a rebated boattail base, the end flattening punch is actually a boattail forming punch. It has an angle on the tip, matching the inside dimensions of the boattail shape. The rounded base is formed both with a flat and a boattail angle, in the BT-1 die. The rebated boattail is formed later, after the core has been seated into the jacket. Normally, only one "E" punch is required for a wide range of jacket lengths. The shoulder on this punch usually performs only the function of centering the punch within the die, and does not push on the end of the jacket. We are not shoving the jacket material by the bottom edge, because we now have the rounded end to push against. The exception is the shouldered punch, which is often made in adjustable style, and is used to stop the jacket from growing longer as a boattail base is formed. Some materials and calibers tend to extrude the tubing jacket forward as you form the boattail base. It can be severe enough to stretch the base angle to the breaking point, so that the base pops off the jacket. The shouldered punch prevents the jacket from moving or extruding forward and solves the problem. Remove the jacket reducing die and punch, and install the floating punch holder. If you are using the S-Press, shift the ram pin into the short stroke position again, and put the stop pin back in the press. If you forget the stop pin, the internal punch for the core seating die will drop down into the ram and you may have to pull the ram out and turn it over to drop the punch out. Speaking of removing the ram, remember that when you pull out the ram-to-toggle pin without the stop pin in the front of the press, nothing holds the ram but luck and friction. It is a good idea to insert the stop pin before removing the ram pin. That way, the ram can't drop out and land on your foot. With the normal core seating die, or the BT-1 boattail preforming die, in the press ram, the press back in short stroke position (hand press), and the "E" end flattening punch in the floating punch holder, lubricate the inside of the jacket and wipe a little lube on the outside as well, and put the jacket over the punch. Raise the ram, and then bring the punch holder down until contact is made between the jacket and the die. Adjust the punch holder so that the base just closes or forms the boattail shape with a flat base. This operation should take place at | |||
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the end of the stroke, using the best leverage, in a hand press. But stop adjusting closer and closer, once the base forms. If the base isn't totally closed, do not try to make it close further in this operation. It will not do so, and the attempt may break the die or bend the punch. If further closure is desired, it must be done by making the tubing slightly longer prior to the first step, and then creating more of a "pipe" on the end of the tubing jacket while rounding the end. Sometimes, in the boattail operation, the jacket may stretch or slip back and open up the base hole beyond what it was before flattening. In that case, an adjustable end flattening (or actually, boattail forming) punch may solve the problem. However, the hole in the base is much smaller than with military full jacket bullets, which are often fired in hot-running machine guns. If the lead doesn't "melt out" of these bullets, it surely will not in a civilian target or hunting gun. Also, if you calculate the amount of force on the exposed core area, versus the amount of force on the rest of the rolled-over jacket, you will find it runs better than 100 to 1 in favor of pushing the jacket rather than the core. The issue is whether the core can be "shot out" of a tubing jacket bullet. Of course, it can, if the force on the core is greater than the force accelerating the jacket. To make sure this cannot happen, tubing jacket bullets should either be bonded, or should use an ogive that wraps the jacket material around the nose so that looking at the bullet straight on, the jacket covers at least 1/2 of the total cross-sectional area. To put this potential problem in perspective, we've been making tubing jacket bullet sets for about 30 years, and our clients have made millions of tubing jacket bullets in that time. So far, we've had about...let's see, ummm...zero instances reported of a core being shot out of the tubing jacket. Looks like a fairly safe bet to say it isn't likely to happen. But still, it could, if you made a non-bonded bullet with a wide open, nearly cylindrical nose shape and not much of a roll-over at the base. Fortunately, there isn't much interest in that shape, in the calibers and styles that people typically want to use with tubing jackets. There is no step 5. You just finished the jacket. Now, regardless of whether it is a flat base or a boattail, you'll want to seat the lead core into it just as if it were a commercial flat base jacket. That is, swage the core, then seat the core in either the CS-1 core seater die (flat base), or the BT-1 boattail preform die. The reason for seating the core is to expand the jacket from internal lead pressure, and form a tight fit between the jacket and core. If you want to bond the core, it would be done now, prior to seating the core. But before you do anything else, clean the jacket of any internal lube. Swage lube inside the jacket will either unbalance the bullet, cause the core to slip when the bullet is fired, or burn into a film that prevents core bonding. Very hot water with a little detergent in it will remove the Corbin Swage Lube. Organic solvents like alcohol, benzene, acetone, and similar non-oily (not kerosene) solvents can be used. Slosh the jackets around in the hot water or solvent, and then let them dry. Lube on the outside is OK, but lube inside is not. The lead cores will also need to be cleaned before insertion into the jacket, whether or not they are to be bonded. To bond the core, drop the core into the jacket, add one or two drops of Corbin Core Bond, and then quickly heat the jacket until the lead melts. Let the core cool, and | |||
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then wash in hot water with a teaspoon of baking soda per quart. Spread the bonded cores/jackets out to dry before you seat the cores. I'll discuss core bonding in more detail later. | |||
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5. Drawn Strip JacketsA second form of jacket making uses flat strip instead of tubing. This is the method used by the mass producer of bullets. Strip material generally costs less per bullet than tubing, and lets you make exactly the wall thickness, wall taper, and length of jacket you desire. In a hand press, the jacket must be kept relatively short, generally under 3/4 inch. But in Corbin's CHP-1 Hydro-Press, you can make 20mm jackets, .50 BMG jackets, or jacketed 12-gauge shotgun slugs if you wish (as well as all the smaller calibers, and jacket walls thicknesses up to virtually solid material). I'm especially pleased with the work that we have done in bringing the costly high-speed production system down to an affordable, lower-volume operation. Until our years of work brought about the JMK- series of tools to make flat strip into quality bullet jackets, you would have been faced with rebuilding old transfer presses that cost at least twenty thousand dollars each, building progressive dies with a shuttle feed for another five to ten thousand dollars, and then buying all the feeder and handling equipment to make it work, plus hiring a die-maker to keep it operating and fix it when it failed. There was no affordable, turnkey package that you could just purchase. You had to design and build it yourself, or hire someone to do it. But now, with a considerably smaller investment, you can make every bit as good a jacket, usually better. More importantly, you can make these jackets in the specific way that will perform best, not just some way that lets them feed fast through an automatic machine. And, you can use ductile, pure copper if you wish, which is normally too sticky for the high speed punch presses: it tends to break out at the base as you slam it through a progressive die. This is the main reason why a five or ten percent zinc content is used in factory jackets. Adding zinc makes the material stronger so it can resist the force of drawing, and makes it a little harder and slicker so it won't stick quite as much on the punch or in the die. By using the relatively low impact of a slower-moving hydraulic ram, Corbin's system eliminates the problem of breaking out the bases with ductile copper material. You no longer have to use copper tubing to get the large mushroomed bullets that don't crack apart on impact. Changing calibers or operations is quick and simple in comparison to a punch press. Twenty minutes would be a long time to set up the Hydro-press for jacket making. Five minutes would be slow for changing calibers. Fifteen hours might possibly give you enough time to get a punch press retooled for another caliber, including the tedious testing and adjustment period. As with most things in life, there is a balance to be made. The punch press system costs as much as a new car and takes days to tool up, so you must make hundreds of thousands of the same part once you have it working. Otherwise, the set up time eats up all the benefit and there is no gain. Your cost per jacket would | |||
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be astronomical. But most shooters and custom bullet makers don't need to make more than twenty thousand to perhaps as many as a hundred thousand jackets a year. That would be a day or two in punch press production time. If you need millions of jackets, the cost and time involved with full automatic presses make good sense. If you need a more moderate quantity, it can't be justified. The Hydro-press can easily justify its own cost with the kind of quantities a custom bullet maker requires. Bear in mind that the goal of making custom bullets is, in fact, the custom feature. If the bullet you want is available from a mass producer and the price is reasonable, buy it. But if you want to fine tune some particular combination of features to make the best possible bullet for a certain purpose, then you need the kind of control over components that a jacket drawing system can give you. Copper StripCopper strip can be purchased from Corbin, or from over 200 copper mill outlets in the United States and Canada. Many of the large copper mills have outlets around the world. Names such as Olin and Revere share space in our "World Directory of Custom Bullet Makers" with the makers of precision brass, gilding metal, German Silver, bronze, and aluminum tubing and strip. You can find their addresses and write for a list of outlets close to you, or direct shipment terms and prices. Generally, for moderate size lots, our prices will be reasonable. But I would encourage you to shop around. Sometimes our prices are far better, during high copper market prices, because we stockpile when the market is low. Copper isn't a bad investment when you have reason to take delivery of the actual material. You just have to know the historical price swings and buy when it is cheaper, or buy futures options and sell them when it goes higher. Sometimes, if you find the market for copper is low, you can buy strip at a better price elsewhere. But generally, the minimum mill purchase will be too much for a lower-volume bullet maker to justify. We sell in five pound bundles or fifty pound coils, for example. Most mills are interested in 500 pound coils, and usually a truck or railcar load minimum. In most cases, if a bullet jacket is selling for eight cents, you can make it from strip for about five cents. But the custom bullet you can make from this jacket typically gets another two or three cents worth of lead added, and then sells for a dollar and a half! Typically you would make from 50 to 100 bullets an hour, depending on the complexity of the bullet. But let's say you could only manage to complete twenty bullets an hour. Your hourly cost is what you could pay to replace your own labor. Just for illustration, let us assume you could hire someone to push the buttons for six dollars an hour. Prices tend to move in relationship with wages over the years, so the example will hold true even if the numbers do not. The one hour labor costs you six dollars, and the material cost for twenty bullets is eight cents each, or one dollar and sixty cents. So the hour's production cost you seven dollars and sixty cents, and the average price a serious shooter will | |||
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pay for custom bullets is a dollar fifty each. That means thirty dollars for your hour's work. Subtract the seven sixty cost, and your profit is actually $22.40. The return on your investment is 294.74 percent! And you wonder why people become custom bullet makers? Are you getting anything close to 200 percent on your money now, sitting in a savings account or in mutual funds, insurance, or any other typical investment? You are the best investment you can ever make: bet on yourself and be a winner! You can use gilding metal (5 percent zinc) or commercial bronze (10 percent zinc) like the factories do, but you don't have to (and they do). These zinc alloys are a little harder, but they are also harder to obtain in small lots because they are binary alloys which can be made in a virtually unlimited number of alloy mixes, grain structures, and tempers. Copper is just one element, and it comes as annealed (dead soft), three-quarter hard, half-hard, and full hard drawn. It comes in a standard and a deep-drawing (non-earing) grade. The non-earing grade isn't completely free from the little lobes or ears that grow on the edge in a deep drawn tube (like a jacket), but the amount of this waste is minimal compared to standard strip used for flashing, welding transformer windings, and other non-drawing operations. An uneven edge is caused by tiny differences in grain or hardness which show up as greatly stretched differences in a deep drawn part. The more uniform the grain, the less earing will occur. The edges need to be finished, so that there is very little burr or waviness in the edge of the strip. If the edges are curled, as they might be when cut with shears or tin snips, the strip thickness appears to be much greater so it won't feed through the slot in the disk cutting die. If the edge is rough or wavy, it will be difficult to pull the strip through the guide slot. A die set is made for a certain width and thickness of strip, as well as a certain material. If we have plenty of your material, we can make special dies for it. Otherwise, we offer the dies made for our own material, and cannot recommend or guarantee operation with anything else. Fortunately, our material is a standard around the world, so you can get it from hundreds of other suppliers. When we design your dies, we will also calculate the correct thickness and width of copper to use for the jacket. You can also do this with a software program called "DC-CUPS", available from Corbin. This program can record specific jacket designs, including details on every step of drawing, and print out a production process giving all the parameters. You can calculate strip width and thickness for any jacket, and even design the jacket given a certain bullet weight, style, caliber and shape. The program works with both strip and tubing.
CU-5 (Copper Strip, 5-lb bundle): Corbin offers copper strip in two packages. First, you can purchase a five-pound bundle of strip, in pieces cut to 18 or 24 inch lengths. We provide our standard .030-thick deep drawing grade pure copper, in a 1 inch width. This is a very practical and versatile size, which can be used for Base-Guard disks, gas checks, half jackets, and all calibers of handgun jackets, and the smaller rifle jackets. | |||
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CU-50 (Copper Strip, 50-lb coil). The most economical weight is the 50 pound size, which we stock in several widths and thicknesses. These are flat, pancake coils with a large "eye" or center hole, which fit on the Corbin Strip Uncoiler machine (CSU-1) for automatic feed into the press. I should point out that the CSU-1 can be used with either the automatic feed die set, or the manual feed set. If you purchase large coils, you'll either need the CSU-1 or something like it to uncoil the strip without kinking it, or you will need to chop it into easily handled pieces. The whole idea of the continuous coil is to let you run the blanking and cupping stage in the "automatic" mode, which really means you keep an eye on it but it runs by itself until you have made the desired count of jacket cups. A counter on the Hydro-press lets you know how many pieces you have made. Jacket Maker Kits (JMK-1-S, -1-H, -2-H)Corbin makes all the tooling you need for any kind of jacket imaginable, from a .14 caliber to a 20mm cannon. The process can be done in a regular jacket-maker die set, or an automatic strip feed system that blanks and cups the strip at better than 600 per hour, no hand feeding required for the first stage. Both systems require handfeeding of the cups into the redrawing and pinch trimming (to exact length) stages. The demand worldwide for these sets has been overwhelming. As a consequence, we often have delivery times that can be over a year. This is not always the case, of course, but it has been in the past and may be again at times (whenever panic sets in because of some harsh new ammunition or firearms law). Find out whether we have anything available in stock, or whether our backlog of orders is extremely long, before you plan a business around the strip jacket making equipment, or schedule a trip to see it or take it back with you.
JMK-1-S (Jacket Making Kit for S-Press): Corbin hand presses make up to .7 inch long jackets from .030 inch thick strip. That covers most handgun jackets, and some smaller caliber rifle jackets like the shorter .22, 5mm, .17, and .14 calibers. It leaves out the larger rifle lengths of bullet jackets, which typically run from .75 to 1.3 inches in calibers below the .50 BMG. For these, you need the Hydro-press, or Hydro Junior. A hand press just doesn't have the starting pressure at the bottom of the stroke to punch and coin a blank of copper, then draw it into a deep cup longer than about 7/10 inch. Sorry: that's just physics. If people were made with 20 foot long arms and legs, then we could build hand presses with bigger strokes. The first stage is a blanking die. You pull the strip of copper through a slot, and work the press handle up and down to punch out little disks. The second stage is a cupping die, which turns the disk into a short, thick cup. The third stage redraws the cup to make it longer and thinner, and the final stage trims the cup, while giving it the final diameter. Detailed instructions are put with each set. The standard kit makes a .45 pistol jacket, from which you can draw other jackets by adding additional JRD-1-S jacket reducing die sets. Because it is necessary to blank | |||
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and cup the jacket at a larger diameter and shorter length than the final trim, we will, in most cases, have to pass through the step of making the cup close to .45 caliber at some early stage, even if you want a 9mm or .32 jacket. Rather than have a lot of different prices or charge what would cover the maximum number of draws for the set, we sell the set to make .45 caliber jackets, and then simply let you add one or more JRD-1-S draw dies and ET-2-S trim dies to produce various diameters and lengths. A .452 jacket can be reduced to .40 caliber or anything in between with one draw. To get down to .38 or 9mm caliber would require a second draw die (you can only reduce so much in a single draw). From .40 down to .354 or anything in between is one additional draw. To get from 9mm down to .30 or anything in between in another draw. And from .30 down to .224 or anything in between is another draw. If we try to push too big a jacket through too small a hole, the bottom just pops out. On the other hand, if you wanted to make .44 Magnum (.429) and .41 Magnum (.410) jackets, we would make the basic JMK-1-S in .452 and two additional draw dies, and you would go directly from .45 to .44, and .45 to .41. The draw dies have a "nest" or guide section, which is designed to align the jacket while it is at a certain initial diameter, and guide it evenly into the reducing section. If you were to make some .429 jackets and then try to reduce them to .41 in the .45 to .41 reducing die, the .429 jacket would not be properly guided and aligned, and you might be some lopsided jackets at .41 diameter. Each draw die is marked with a starting and ending diameter, and it means what it says. Likewise, if you decide to reduce a jacket with a different wall thickness, this could be a problem. For instance, if our JMK-1-S made a .452 jacket with a .015 inch thick wall, and a jacket reducing die was made to take these down to .400 diameter, the clearance between the punch and the die would be such that the thin wall jacket fit easily. But if you found some .452 jackets with a wall thickness of .020 inches, and tried to push them through, they might become stretched out excessively or even generate so much pressure that the die or punch could be damaged. Jacket making tools are precision devices. As long as they are used with the materials intended, they deliver excellent results.
JMK-1-H (Jacket Maker Kit, Manual Strip Feed): Hydraulic power presses, such as our Hydro-press, have full power from the bottom of the press stroke to the top. The JMK-1-H is designed for use on the CHP-1 or the CSP2H Hydraulic press. The CHP-1 is designed with electronic sensors that can accurately determine the stroke length and the pressure, and can interface with the CSU-1 Corbin Strip Uncoiler. You can set up both pressure and position stops, which will prevent the ram from bending the various punches and crushing the pressure pad springs used to hold flat strip so it will not fold as it is drawn into a cup shape. The CSP-2H does not have all the controls of the CSP-1 nor does it have automatic pressure transducers, but it does have position sensors, which allow it to be used safely with this manually-fed die set. | |||
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In the JMK-1-H kit, there are usually four stages, but the exact number depends on the length, thickness, caliber, and taper of the jacket wall. We can build almost anything for you, working backward from the jacket you want to get the proper strip width and thickness. The first stage is a blanking die. It cuts a disk from the strip of copper. You simply pull the strip through a slot in the die, as the ram goes up and down. Disks, like coins, are punched out. The second stage is a cupping die, which has a spring-loaded pressure pad around a punch. The disk is put into the die face, in a recess made to hold it. The pressure pad is run up against the disk, and it holds the disk by its edge while a punch travels up and draws the disk into the die, pulling it from under the pressure pad. This keeps it from folding or bending. A third stage redraws the short, thick cup into a longer, thinner jacket. This stage could be the final one, for short jackets. Or it might be repeated one or more times for longer and thinner ones. Until we know precisely what dimensions your jacket is to have, we cannot say how many steps it will take to make it. The last stage is a trim. The trim die is normally the ET-2-H, which is adjustable over a reasonable range of lengths. This means you can make just about any reasonable range of lengths from one set of tooling. We still would like to know the range of lengths or the main length that you want, so we can see if you will need additional trim dies to cover it. Each jacket maker kit is designed around one specific caliber, wall taper, and a specific material. The dies control diameter at each step, and the punches control the wall thickness and wall geometry such as taper or length of straight section. If you change these parameters, it means a change in the associated tooling. We would need a supply of the initial cups in order to change the rest of the set and to develop the correct dimensions for the punches and dies. Most of this work is experimental, in the sense that we need to actually draw your cups to see how best to configure the punches for any given stage. It is partly art and partly math. So, you can see that jacket drawing equipment is not easy to design and may be difficult to modify, or quite easy, depending on what kind of jacket dimensions it is originally made to produce, and what kind of modification you intend. Sometimes you can draw down an existing jacket to smaller calibers, longer lengths, and thinner walls just by adding a stage or two to the operation. This may result in two or more practical jackets from the same die set. But don't count on it in every case! If you initially budget one complete die set for each length, each caliber, and each wall taper or thickness, you may be pleasantly surprised to save money by using fewer tools to achieve a few of the different effects. But if you count on using one die set for a wide range of jackets, it might not be possible, and then your budget would be shot, your plans ruined and your dog might scorn you, too. We'll let you know any time we see a good way to save money by using any of our tools for multiple purposes, and ask if you want to change your order to accomplish that. As I said earlier, your success is what builds our future, too, and I'd rather take the long view and save you money now so you'll be a bigger success tomorrow and buy more equipment from us when you need to. | |||
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JMK-2-H (Jacket Maker Kit, Automatic Strip Feed) The Hydro-press has special plugs and screw holes made so that you can install this rather amazing system. It has a lubrication roller system to put lube on the strip, a roller-cam hitch-feeder, and an interesting kind of blanking and cupping die all combined into one unit. The jacket material is automatically fed in, lubricated, blanked into a coin, drawn into a thick, short cup, and carried out into your container, ready for redrawing to a longer, smaller diameter jacket. The entire assembly replaces the head (and in some designs, the ram) of the Hydro-press. You remove the rear cover of the press, unfasten two nuts that hold the press head and rods onto the base plate, unscrew the ram from the cylinder, and pull the head and guide rods off the press along with the ram (again, in some versions). Then you install a new head (and ram, if required), and put the hitch-feed mechanism on it according to directions that come with the system. The CSU-1 Corbin Strip Uncoiler is used with this system to provide a steady source of material without undue drag on the feed. The uncoiler is controlled by the amount of sag in the strip, which loops from the 50 pound coil to the press head over a seven foot distance. A separate sensor stand has upper and lower limit switches that detect when the strip is pulled snug. The upper limit switch then trips, turns on the uncoiler for a brief, quiet partial turn, feeding out a few more inches of strip. This lets the strip sag until it trips the lower limit switch, and stops the uncoiler. It's fun to watch this run, because it is almost silent and seems to anticipate the needs of the press. Without this device, you would have to devise some other way to keep the hitch feed from lifting or pulling more than a pound or two of resistance. Otherwise, you would not have reliable feeding, and the die or punch assembly might be damaged unless you cleared the partially cut disks before another stroke mashed the parts together. The press can also controlled by the strip feed, with a sensor that detects the metal's presence and shuts off the press when the strip begins to run out. The optional sensor package can also detect non-movement of the strip and stop the press if a jam occurs. The JMK-2-H consists of three separate parts that you can use to mix and match with other calibers in some cases. The automatic press head assembly can be used with any caliber or size of blanking and cupping die set. It is the hitch feed, strip lubricator, die holder, and all the other general machinery that makes the system work, except for caliber-specific dies themselves. The blanking and cupping die might also be used for several calibers, and can be changed separately from the head assembly. It is made for a certain width and thickness of material, which will be drawn down to make a certain caliber, taper, wall thickness, and length range of jacket. Each jacket has one blank diameter and width that maximizes the use of material. But often, there are other calibers you could make with it. A short, heavy walled jacket might be possible in a large caliber, such as .45 ACP, using the same strip that makes a longer, thinner, but smaller diameter caliber such as the .308 rifle. I can't publish a table here that shows what is possible, because all the various parameters make it too complex. When we make a jacket maker set, it is | |||
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designed for one specific jacket only. Then, after that is working fine, we try to figure out if there might be some other useful calibers in certain lengths and wall thicknesses that could be gotten with the same blanking and cupping die, by using different redrawing and trimming dies. You can purchase the DC-CUPS software program (for any MS-DOS or Windows compatible computer with a hard drive) to calculate all this and much more, including costs of jackets, and recording and printing the operation steps for making any jacket. The redrawing and pinch trimming dies are the same in the JMK-1-H and the JMK-2-H. In fact, you can add the automatic feeding die head assembly and the blanking and cupping die that fits it, to an existing JMK-1-H set, to create a new JMK-2-H set. That's the same as saying you can upgrade the manual jacket maker just by adding the head and first stage die assembly (which is a significant part of the total price for the auto-feed jacket-maker kit). You can also buy just the redrawing dies or final trim die, if your particular jacket set would be practical to convert into another caliber (we have to figure that out on a case by case basis). Generally speaking, you would want to plan for one complete JMK-2-H set for your style of jacket, and then just the dies (both the first stage and the redraw and trim dies) for any other jackets. If we get lucky, maybe some of the jackets can be made using the same original strip width and thickness, which means you don't need another first-stage die. I hope that isn't too badly explained. Just think of the pages I'd need to write to explain how the factory 12 station jacket maker press works! This one only has from three to six steps, typically four steps, depending on the length and thickness and caliber of jacket. Corbin publishes a manual called the Guide to Jacket Making which is incorporated into the larger book, World Directory of Custom Bullet Makers. If you are interested in manufacturing jackets from tubing or from copper strip, you would benefit from reading it. The World Directory also lists wholesale suppliers of copper and lead, custom bullet makers from around the world, and has a wealth of information about the commercial aspects of custom bullet making. When we build a jacket making kit, we send you full instructions and pictures of the set up and operation. You are also welcome to visit before we pack the equipment for shipment (which takes most of a day). If you can come to the die works when we have just finished building your jacket making outfit, and while it is still set up on either your new Hydro-Press or on a test press, then we can show you in person how to set it up and run it. You are always welcome to visit. | |||
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6. Base-Guard BulletsYou can swage bullets without jackets, using just the lead, or you can swage jacketed bullets, but there is a kind of hybrid design that reduces the cost and increases production speed while extending the usable velocity range beyond that of a lead bullet. In fact, this special design, called the "Base-Guard", can let you shoot pure, soft lead bullets at up to 1,400 feet per second without fouling the bore, without using any lubricant whatever, and even cleans fouling from your bore as you shoot! Years ago, the Harvey Prot-X-Bore bullet stirred up some mild interest because it made similar promises. The bullet was a plain lead pistol slug with a zinc washer swaged to the base. The lead would extrude through the hole in the washer, and form a rivet head by flowing into a larger diameter, shallow dome-shaped cavity in the face of the base punch. We made many of these die sets for clients, but I was never convinced the design worked as well as some people claimed. The National Rifle Association tested it at least twice and both articles concluded that there was no difference between using the zinc washer and shooting a plain lead bullet. Both fouled their bores. But people kept buying the zinc washers and dies, so someone must have had good luck. Shooters don't generally keep doing something that doesn't work, yet I was not having much luck with it. So, with the help of several relatively famous shooting friends, people who set world records and were serious about their bullets, I conducted a long series of experiments to find out whether the zinc base bullets really worked or not. I found out, after thousands of rounds, that zinc itself has little to do with the fouling or not fouling. Aluminum, sheet steel, brass, copper—all of these materials would work, or not work, equally well. It all depended on two factors. When both were right, the washer bases worked wonderfully, making it possible to eliminate the jacket and build bullets that kept the barrels clean, at very low cost and at high speed. When either one was absent, the idea was a miserable failure with fouling that just about plugged the bore! Here are the two factors. First, the washer or disk has to be precisely the diameter of the bullet. Even a ten thousandth of an inch undersized is too much. At the pressure developed by even the lower powered handguns, lead will flow back under the disk unless the disk fills the barrel to the very bottom of the rifling grooves. When I measured the zinc washers (which are stamped out of sheet zinc in a high speed punch press), I found variations of up to 0.002 inches! That is twenty times greater than the minimum required to work! But once in a while, I found a short run of zinc washers that actually measured a little oversized, or perhaps right on. Those worked, provided the other factor was present. | |||
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The second necessary design factor is that the washer must have both a sufficient thickness and strength to resist bending under the drag force on its edge as it speeds along the bore, and at the same time it must have a sharp, burnishing-tool kind of edge facing forward to seal and scrape fouling out. If the edge is rounded, or if the material is thin enough to bend backward under the stress of firing, the lead will flow under it, and be smeared along the bore, filling the rifling with fouling. But when the diameter is perfect and the edge is sharp, and facing forward, a thick enough disk will work wonderfully, making an astounding bullet that is cheap, fast, easy to build, and that works without the need for any lubrication, at least up to the speed where the material is bent back from drag and inertia and effectively quits presenting its scraper tool edge to the fouling. The metal did not matter. We used barn siding, tin cans, shim stock brass, and copper jacket material as well as zinc. In fact, copper seemed to work better. The main thing was the difficulty in holding such tight diameter tolerances on a low-cost part. The high precision disks were just too costly to make, but they worked fine. They worked better than a half jacket on handgun bullets and on .45-70 rifle bullets. So, the problem was how to make them almost perfect zero tolerance diameter and also how to form the sharp edge without a lot of expense. We realized that if the disk were cut slightly oversized and made cone shaped, the diameter would effectively be reduced so it would easily drop into the swage die. But when pressure flattened the conical disk again, it would grow back to original size! The die wall would stop the growth, and any extra material would be forced to extrude forward, into the soft lead bullet, just below the edge. The other side would be backed up by a hard steel punch, blocking any extrusion in that direction. We had the answer! Just make the disks conical and slightly over caliber before the cone shape is applied. Then, the cone will drop into the die, grow to full diameter plus a burnishing tool edge, and there will be absolutely zero tolerance between the diameter of the bullet (the lead part) and the diameter of the base disk! It could be no other way: both parts receive their final diameter from the swaging action, within the same die, at the same moment. A second benefit is that the disks work in a wider range of calibers. A disk made for the 9mm pistol would also work in a .357 Magnum, and a disk made for a .45 ACP would grow enough to fit a .458 or a .45-70 (which has a groove to groove diameter about 0.006 inches larger than the pistol). The .41 caliber disks worked fine in .40 caliber barrels. And they all worked amazingly well in nearly every gun, provided the bore was in good shape and the bullet diameter was either exactly groove to groove or slightly larger. One of the special advantages of using no lubricant is that there is no puff of lubricant smoke, which means that the Practical Pistol shooters don't have to try for double-taps while looking at an obscured sight picture on the second shot. When you are firing two shots that come so fast they sound like one, lubricant smoke can be a problem. | |||
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The big advantages of the Base-Guard are that you can make the bullet in one, or at most, two, strokes of the press, and the cost is almost the same as a cast bullet without the disadvantages of lubricant, extra handling, hard lead alloys, and rejects. I have made four hundred bullets in just under an hour, including cutting the lead wire, swaging the bullets and making the Base-Guards! Base-Guards are superior to gas checks and half jackets in three ways. First, they cost less, usually about half the price of gas checks and a fourth the price of half jackets. Second, they turn with the rifling on their central axle instead of being pinched against the bullet, so if the bullet slips in the rifling, the Base-Guard keeps tracking and seals the gas. Third, they scrape fouling out of the bore, instead of ironing over it again and again. Gas checks and half jackets rub more lead on the bore and then pass over it with the smooth side of the copper. Base-Guards are like a tool bit, presenting their sharp edge to the fouling and machining it off like a lathe bit. Try turning a lathe bit sideways to the work: that's how a gas check looks to the fouling plastered along your bore! If you use preformed Base-Guards, which we offer in bags of 1000 at a very low cost (barely more than the cost of material to make them), you can turn out up to 500 bullets an hour. Or, you can use .030 to .040 inch thick copper strip and punch out the Base-Guards yourself, using a BGK-1-R, BGK-1-S, or BGK1H Base-Guard kit. The BGK-1-R works in your reloading press (assuming it is similar to the RCBS Rockchucker). BGK-1-R (Base-Guard Kit, type -R)This tool is a threaded die with a slot cut more than half way across one end. The section below the slot is closely fitted to a punch. The punch screws into the press ram. You would use it by stroking the ram up and down only enough to move the punch past the slot and back down to let a piece of copper strip pass through. As you stroke the ram up and down this short distance, you would advance the copper strip through the slot, always making sure that you bring the last hole past the edge of the punch before the punch comes up and cuts out another Base-Guard disk. The disks begin to come out the top. BGK-1-S (Base-Guard Kit, type -S)The die screws into the press head from the bottom, up. This is just the opposite of most kinds of dies that fit the press head. The threads point UP, not down. The slotted end of the die faces the ram. The punch is never removed from the ram during operation, so there is no possibility of it striking the edge of the die and breaking the portion below the slot. | |||
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The press ram is stroked up and down just enough to push the punch through the strip and cleanly cut out a disk, then the ram is lowered to clear the punch from the hole in the strip, and the strip is pulled forward. Repeat this process until you are buried alive in as many Base Guard disks as you can ever shoot. Corbin sells the .030 X 1-inch wide copper strip in five pound bundles and 50 pound coils. BGK-1-H (Base-Guard Kit, Type -H)This die set works in any Corbin press designed for -H dies, such as the Hydro-Press or Mega-Mite. It is substantially the same design as the -S and -R sets, with dimensions and threads scaled up to fit the larger presses. The operation is the same: pull strip through the slot while the press is made to stroke up and down in short strokes, punching out disks which eventually emerge from the top. If you wish, we can build a feed chute for the die, so that cut pieces are fed by gravity down the sloped channel and into a waiting container. This is not a stock part, but it can be built with your die. Converting Dies to BG base:You can add the Base-Guard option to any of your existing sets of dies, just by ordering the appropriate base punch. The Base-Guard punch does no harm if you use it for lead or conventional jacketed bullets: the only difference is that your bullet will have a little round bump projecting from the very center of the base, which only serves to identify your bullet and has no other effect. Here is what you would need to order, if you want to add the Base-Guard capability to any set of dies: For any LSWC-1 set (Lead, Semi-Wadcutter single die), you would want (1) PUNCH-M (or -S, or -H depending on the die), Internal, BG, and specify the diameter. The BG base only works with a flat base. It is ineffective or worse with boattails, hollow bases, or paper patch (undersized) bullets. We have, however, made tooling to produce rebated boattail (RBT) lead bullets, with the BG disk formed at the rebate, using a much larger than standard hole in the disk. This would be a special order item. For any FJFB-3 set (Full-jacketed, Flat Base three-die set), you would want (1) PUNCH-M (or -R, -S, or -H), Internal Core Seat (CS), BG, plus (1) PUNCH-M (or -R, -S, or -H), External Point Form (PF), BG. Whenever you apply the Base-Guard in the core seater and then shape a smooth ogive in the point former, you must use a matching base punch for both dies, or the little rivet head will be smashed flat and made less effective at retaining the Base-Guard. | |||
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7. Draw DiesDrawing dies have a hole all the way through, and they fit into the press head. You push a jacket or a bullet through them, in one side and out the other, to make the part smaller in diameter. Since the die screws into the press head, there is really no difference in the 7/8-14 threaded die body for type -R or type -S sets. The only difference is the punch, because a reloading press (-R) uses a T-slot ram and Corbin presses use threaded rams (5/8-24 TPI for the S-Press). The -H dies utilize tougher materials that stand up under greater force and speed. Part of the reason they cost more is because of the additional time it takes to form and heat treat this material. You can adapt a -M or -R draw die to a Hydro-press, but it is not as economical as it may seem because of the possibility of breakage and less efficient use of the available stroke for alignment and guidance of the components. The JRD-1-S, -R, or -H is designed for home use and occasional use in making short production runs. For longer life in higher volume work, the JRD-2-S or -H is recommended. This version is made from even harder and tougher materials than the conventional design, which require more labor in machining and in the more elaborate heat treatment process. The choice of price ranges gives those who do not need the extended wear resistance a more economical choice for home or lighter duty production. Die life with any draw die or swage die is to some extent subjective: it depends on what you consider "worn out". A high precision benchrest bullet maker might consider a die worn out when the wall concentricity increases by 0.0001 inches, or the diameter of the jacket increases by 0.0002 inches. This might happen after 25,000 to 50,000 jackets have been drawn, or it might not happen until 100,000 or more have been drawn, depending on ambient conditions and use of lubricant. Dust, heat, and abrasive airborne materials in some locations can cut die life in half. On the other hand, a person making premium hunting bullets might find that even 0.0005 inch wall run-out or 0.001 inch jacket diameter change has no effect on the practical accuracy of the bullet. In fact, if the jacket fits into the core seating die easily enough, there is hardly any effect on final parameters no matter what the actual jacket size, since the bullet diameter is only slightly affected by big changes in jacket diameter prior to core seating. The jackets are always smaller than the bullet, before swaging. Whether a production JRD-2 die is an economical buy or not depends on how many draws one plans to make, how clean the jackets will be, whether proper lube is likely to be used, and how much variance can be allowed before one considers the die worn out. Generally, high volume operations, especially those using hired labor instead of doing it all themselves, and operations catering to extreme accuracy buffs, would be wise to get the commercial version of the tool. Everyone else will probably get a lifetime of use from the standard version, if the jackets are kept clean and properly lubricated. | |||
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Special high precision jacket draw dies can also be made, on special order, for benchrest jacket drawing. The tooling is designed differently and is more involved, to maintain higher wall concentricity than a standard jacket draw die. These dies are priced by quote, depending on your specifications, and are designated JRD-2-SC or JRD-2-HC. Their appearance may vary depending on how precisely one wishes to control the parameters. Type -R dies are only available in the standard design, because it is not practical to use a reloading press for high precision or high production work. A reloading press would be incredibly hard to use for production work (think hydraulics!) and to attempt to use one for high precision jacket drawing of the benchrest class would be an exercise in futility. It seems curious that people are willing to spend several thousands of dollars on "benchrest" swaging dies, and then use them in a reloading press, which has no bearings, no hardened ram, no hard chrome ground finish to help keep the ram from wearing out of alignment, and an alignment which, though adequate for reloading, is hardly in the class of an actual swaging press. (To be fair, some people do spend hundreds more dollars having a conventional case frame press re-bored for better alignment and put a different ram into it. But wouldn't it be cheaper and better to start with a press that had high precision and long life designed in, instead of tacked on?)
JRD-1 or JRD-2 type -R, -S, -H (Jacket Reducing Dies)You can produce special jackets by drawing down an existing larger caliber to produce a smaller diameter, longer jacket. This method is often used to make some of the less popular calibers, or to make heavy-walled .224 jackets by drawing down a .243 jacket. It is also used with a Corbin JMK-1-S jacket maker set to reduce the .45 caliber jacket which this kit initially produces, to other sizes. A .45 caliber jacket can (usually) be made into a .44, a .41, or a 40 in one stroke. A .44 can be made into a .41 or .40 caliber. A .40 (10mm) can be made into a 9mm or a .357 caliber. A .30 can be made into a .284, .270, .264, or .257 jacket. Each reduction makes the jacket longer, smaller in diameter, and tends to make the jacket wall somewhat thicker up to the limit of the base material itself, since it pulls base material into the wall area. Wall thickness can be controlled by the punch to die clearance, however. Drawing is the opposite of swaging. People sometimes ask about "swaging down" a bullet to make a smaller one. That is wrong. Making something get smaller is called "drawing", and it is done by pressing the jacket or bullet through an annular die (a "ring die", we call it). The part goes in one side and pops out the other, where it springs back slightly larger than the hole size. We need to have sample material to draw down if you want the parts to come out precisely, since different materials and lots will spring back a little different amount. Swaging always expands a smaller component to become larger. If you try to push a larger bullet into a closed swaging die with a hole even slightly | |||
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smaller than the bullet, you'll make it stick in the die. The material wants to spring back toward original size, so if it was originally larger than the hole, it will keep trying to grip the die walls. On the other hand, if you do it right and use a component smaller than the hole you are about to shove it into, it will go in easily, expand under pressure until it hits the die walls, and as soon as you relax the pressure, the component will spring back slightly toward its original smaller diameter, releasing its grip on the die walls. In a drawing die, you can apply a lot of pressure to the full diameter of the bullet, or to the inside diameter of the jacket, and push it right on through, even though it is trying to grip the die walls. In a swage die, especially a point forming die which relies on a tiny ejection pin, this isn't possible. Benchrest shooters often ask about concentricity of a drawn jacket. Since all jackets are drawn at some point, this isn't a unique issue with redrawing. Concentricity is measured in thousandths of inches of run-out, the difference in the jacket wall thickness as you measure around the jacket at any given distance from the end. A typical tubing jacket might have a run-out of 0.001 to 0.002 inches, which is fine for hunting applications but about 10 times greater than you would desire for benchrest shooting. With higher quality tubing, the run-out of the jacket is improved over ordinary plumbing, which can have a run-out greater than .003 inches. Still, ordinary plumbing has been used for decades to make good hunting bullets. The original Barnes bullets built by Fred Barnes used nothing more than plumbing copper tube for jackets, and Barnes was quite successful. I remember that Fred used to pull tubing through a home-built die by chaining a bar of steel to a tree, said bar of steel having a funnel-shaped hole in it, and then forcing the crushed down end of a piece of copper tubing through it, clamping the end of the copper tube to another chain tied to his car bumper, and pulling a 20 foot section of tubing through that "die" with his car! It was after World War II and things were tough! Successful people were resourceful. But the point is, it worked. How much better we have it today! —Precision equipment is available to use high grade tubing that you can get in a few days with a phone call to Corbin! Fred would have traded two cars for the convenience, not to mention the additional accuracy (of course, he's long departed this world, but I get the feeling that his spirit peeks down and chuckles with glee now and again). The run-out of a jacket drawn from flat strip starts with the cupping operation, and is caused by a number of factors. The first is the quality of the strip that you use. If it is thinner on one side, it will draw a jacket with more run-out than if it is closely matched in thickness across the width. Also, if the grain structure of the material is consistent, and properly aligned and sized, it will draw more evenly than, say, roofing copper or decorative copper sheets cut into strips. One a cup has been formed, it is drawn smaller in diameter, which puts the material volume into length. The thickness of the cup walls usually is reduced in the drawing, so that the base material remains about what it started in the strip, and the jacket walls can either taper or simply be drawn to a more or less straight wall of less thickness than the original material. Drawing a cup to smaller diameter means that the punch which must fit inside and push the cup through the die | |||
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has to fit inside after the cup has been reduced. Therefore, the punch will be smaller than the inside of the cup before it is reduced, and may not be perfectly centered. This is a major source of jacket wall eccentricity or run-out. To help solve the problem, Corbin jacket reducing dies feature a "nest", which is the term for a section of the die that accepts the original jacket diameter for a sufficient length to insure that the jacket is perfectly aligned with the smaller hole that will reduce it. The nest aligns the jacket before it starts into the actual draw. This greatly reduces the amount of run-out in the jacket walls. The punch still is able to wander slightly inside the cup even if the cup is aligned perfectly with the die, and it may force the material to draw slightly heavier on one side as a result. The effect is minimal with a nested die, but to further reduce run-out, the punch can be a special guided or sleeved design. One version we have used for this in the -H dies utilizes the built-in bearings and holes in the press head that are for the stripper device. Two threaded 0.250-inch diameter rods drop through these holes, and are stopped by a nut on the top of each. A steel plate joins the two rods on the bottom side, below the press head. A hole in the enter of this plate allows the draw punch to pass through. A steel button is placed around the punch, on top of the plate. This button is a very close fit to the punch, so the punch just slides through it. On the top side of the button, a thin shoulder is machined so that it slips inside the jacket and fits very closely. You press the jacket over the top of the button, so the raised shoulder fits inside. Now the jacket mouth is aligned on the button, and the button is aligned on the punch. The punch will contact the center of the jacket or cup, and cannot wander off to the side. In another version of the tool, a spring around the punch supports the shouldered button. The thin part of the button is not long enough to fit inside the smaller diameter of the die. It remains within the nest area during the draw. This optional high precision option is added to the draw die on special order. When it is included with the die, a letter "C" is appended to the catalog number, as in JRD-1-SC or JRD-2-HC. This "Custom" designation indicates that the die is a special purpose, custom version. For most purposes it is not necessary to add the benchrest alignment feature, but for the tightest wall thickness control it is a useful addition. There is no point in making these in type -R, since no serious benchrest jacket maker would use a reloading press (or a wine press, pants press, or printing press) instead of a real bullet swaging press. BRD-1-R, -S, -H (Bullet Reducing Dies)You can draw down existing bullets, but only within very small limits: if you try to reduce an existing bullet more than about .006 inches, the amount of lead you are moving becomes significant enough to materially spoil the accuracy and looks of the bullet, and the stresses in the jacket material will begin to cause serious "banana-shape" distortion. | |||
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This means making a 9mm (.355 inches) bullet from a .38 (.357 inches) slug is easy and practical, while making a .41 caliber from a .44 caliber (.429 inches) gives miserable results. A practical limit is making a .318 inch diameter 8mm bullet from the modern standard 8mm of .323 inch diameter. There is a huge difference between drawing a jacket, and drawing down a bullet. A jacket is just the empty cup. You put it over a punch, and shove it through the die by pressing on the inside of the base, so it is drawn over the sides of the punch. You can reduce a jacket by at least two or three times the wall thickness, easily. Don't confuse the .006 inch reduction limit for bullets with the vastly larger potential reduction for bullet jackets. Also, like most things in life, this rule isn't written in stone. Some few bullets with nice soft jackets and room for the lead to go into a hollow cavity or base can be reduced more than .006 inches But you are asking for trouble if you want to do that as a general rule. What might work sometimes on a particular experiment, may fail almost all the other times with other materials. This gets some people into trouble: just because something happens to work one time, they think it will work in every instance. Not just in bullet swaging, this is a common mistake. A fellow takes a big elk with a .243 target bullet, and from that day forth he is convinced that a 6mm is big enough for game the size of an elk, and that there isn't any problem using bullets constructed for target shooting, with their thin jackets and non-bonded cores, on noble game. Sure, you might do it once. If you are a great shot and a superb hunter, you might do it all the time, but I couldn't. The odds are overwhelmingly in favor of most people just wounding the animal and having it get away. In swaging, if something works that maybe shouldn't have, then that's a reason to carefully experiment and find out why. It's bad judgement to assume it will always work in every instance, especially if others who have spent years in the field are dubious. You may have found something new, but try it on several calibers, styles, and materials before you count on it always working. Drawing down bullets is certainly one area where you can find all kinds of exceptions that work, but only because the material, hardness, and style are just right in a particular instance. Corbin will make tools for you to your specifications, against our own advise and experience, provided you take responsibility if they don't work. If we design and recommend the tools, then of course we guarantee they will work. Draw dies for the Hydro-press (type -H dies) are more sophisticated and can produce results that may not be possible in a hand press. The long stroke and great power of the Hydro-press give us room to build special guide sections and ejecting punches that won't work on a hand press. In drawing, full power is generally required at the start of the stroke, not just at the end (as with most swaging operations). | |||
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Since nearly all the hand operated presses have about half an inch of extremely high pressure travel toward the end of the stroke, and progressively lower pressure as you retract the ram, it follows that drawing operations which may require high pressure over a longer travel than about 7/10 inch may not be practical in a hand press. Can you draw down a solid copper bullet or a full jacket military bullet? Probably. If you want to order a bullet reducing die, you really need to send us five or six samples of the same bullet that you plan to draw down. Then we can test the idea, and use your bullets to adjust the die so that it produces the correct diameter, given the amount of springback in your particular bullets. For some reason, there seems to be a general reluctance to send sample bullets. Maybe it is the desire to get the dies faster, not waiting for a chance to go get the bullets and ship them. Maybe it is a feeling that this is a waste of time and not necessary. Or maybe it is just to save the cost of shipping them. But for whatever reason, it isn't that unusual for someone to balk at the idea of sending samples to draw down. When that happens, we have no way to tell if your particular bullet will come out the same size as the ones we must then use to test and adjust the die. Also, we don't know if you are not telling us about a special base shape that might be distorted if we just make a normal flat base punch. In fact, we just have to go on blind faith that your bullets are actually close to what we can make or get easily here for testing. When you don't send samples, the only thing we can do is guarantee that the die is in fact a nice draw die that makes the size you said with the bullets we choose to use. We can't guarantee that the die will make the same size with your bullets. If it doesn't, then it is your problem. You can order another die and send samples this time, but the first die is still yours and can't be traded back in (because the next person who sends in sample bullets will want a die make properly to fit them, not your die). If you know this, accept it beforehand, and will be happy with the results even if there is a difference of up to .001 or so inches between what the die makes with our test samples and whatever bullet you choose to push through it, then we are happy to skip the samples. If you tell us that you want a draw die to reduce a Sierra .338 bullet down to .333, and instead of sending us the sample bullets, you send us the Sierra stock number, then you'll also have to send enough extra payment so that one of our die-makers can drive into town and shop for a box of those particular bullets, which is a minimum of about an hour plus the cost of the box of bullets. We will be glad to send the rest of the bullets along with your die, and of course the drawn samples used to make and test it. But that extra hour of the die-maker's wages might seem steep, and I agree. It is probably much cheaper for you to send us the sample bullets than for us to try and locate them. Still, whatever you want is fine, so long as the cost of doing it is acceptable. That is the bottom line for anything that is moral, legal and safe. Bullet drawing dies are used by screwing the die into the top of the press, and putting the punch into the press ram. The die should be set high in the press, when starting. Two or three threads of engagement are enough. Put the bullet on top of the punch and guide it into the die mouth. If the bullet does not draw down | |||
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or pass through the tight part of the die, lower the die until it does so at the end of the press stroke (for hand presses). In a power press, you can set the stroke length and position for your convenience, since you have enough power anywhere in the ram travel. For a hand press, the job becomes much easier when you use the very end of the stroke to get the hard work finished. In most cases, the bullet will need to pass through the tightest point in the die on one pass. It may not necessarily emerge from the top of the die, but it should be loose inside, not stuck halfway through the draw, before you insert another one. One bullet can "lift" another one up, but if you try to actually use one bullet to finish drawing another, it is likely that the nose will be damaged on the second bullet. Corbin Swage Lube is always a good idea, applied just by touching the lube and then rolling the bullet between your finger and thumb as you insert it. With special base shapes, you may need a special matching punch. For instance, a rebated or conventional boattail bullet may suffer some base damage and expansion if you push it through a draw die with a flat punch. A punch with a "socket" to accept the base of the bullet will still need to be smaller than the original bullet, since it must pass through the die. This means the angle has to be very close to the original bullet, or else the edge of the punch might press into the tail of the bullet and mar it. To expedite production, especially on the Hydro-Press, we can make a sleeved punch with a spring loaded collar. The spring goes around the punch, and the collar sits on top of the spring, helping to hold and guide the bullet into the die. In fact, the collar might be made so it fits into a recess in the die, pre-aligning the punch so its fragile edges will not be damaged by hitting the die face. This sort of work is available as custom jobs, usually quoted and not found in the price list, because we don't know in advance in every case just how much time and effort will be required to design and build a given solution. Typically, though, the additional cost of a custom punch is all it takes, which at this writing is slightly more than twice the cost of a standard punch. The difference is speed of use is quite remarkable. We can put a metal chute on top of the die, as well, to roll the bullets down into a bucket or other container, so you do not have to handle each one as it comes out of the die. All these things are overkill for the hobbyist, who is only doing a hundred bullets or less at one sitting, but they quickly make the difference to a custom bullet maker who is salvaging 50,000 pulled 50 BMG bullets and needs to process them as quickly and easily as possible. The cost of doing these things is not significant compared to the time they save in commercial applications, but the price of a good die without the speed features may already be right on the edge of what a hobbyist could justify. I understand. That is why we don't build everything possible into every product, but offer many of them as options for people who find them valuable, while keeping the basic tool prices as low as we can with high quality work and material. It is no problem to add features to a good tool. I've never regretted buying anything that was too good for what I was doing. All it did was cost a little more than I might have spent otherwise. But often I found later that there were other, new things it could do, and I was glad I spent a little more for it. | |||
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My wife bought me a very high resolution digital camera for a birthday present, and I seldom use more than its lower middle range of resolution, and not many of its special features. But every so often, I am glad it can deliver a high quality, big format photo, or do some trick that I have to break out the manual to accomplish, even if a much lower priced camera would do 90% of my work. Just having the option of doing more is comforting. I can add options to it that work right, whereas adding them to my lower priced cameras would be frustrating, since the basic tool itself would be too limited to really take advantage of things like sharp telephoto lenses, macro flash attachments and microscope adapters. The same is true with swaging tools. If they are built better than you probably need today, then tomorrow when you decide to try something more demanding, they will deliver. But it is frustrating to add features to tools that are working right at their limit, as with a poorly built die set or a reloading press used for swaging. (Have I mentioned that swaging presses do a much better job? Really? I must be getting forgetful in my old age, and starting to repeat things!) RFJM-22 -R, -S, -H (Rimfire Jacket Maker, 224 caliber)One of the most popular tools we've ever made is the Rimfire Jacket Maker set, which turns fired .22 cases into excellent jackets to make .22 centerfire bullets. You've probably read about this before. RCBS, Speer, Hornady and many other firms got their start by doing just this. You can do it today, and with the price of bullets, it is more popular than ever. Fired .22 short cases make great 40 grain Hornet jackets. Fired .22 long or long rifle cases make the standard .705 inch long 52 to 60 grain open tip or small lead tip bullets for all flavors of centerfire .22 cartridges, from the .222 to the .225. Some shooters don't realize that all modern .22 caliber centerfires, including the 5.56mm, actually use the same diameter barrel (a nominal .224 bullet size fits them all). The .22 high velocity loads such as the "Stinger" use a case slightly longer than the standard long rifle, which will produce a little heavier bullet. You can make 65 to 70 grain .224 bullets using these for jackets. The process is simple. You wash the fired cases to remove grit. I like to boil them in a mixture of water and some detergent, plus a little vinegar to help restore the shine. Then, I pour off the water, and spread the cases out on an old cookie sheet. I fire up the kitchen oven and heat the jackets quickly to drive off the water. Shortly, I have a tray full of clean, dry cases. I take them out, and put the jacket maker die in my press. The die itself is the same for both reloading presses and for our S-Press. The -R differs from the -S version only in the punch. In the reloading press, the punch has a T-slot head or button, like a shell-holder. In the -S version, to fit our S-press, the punch has a kind of die body attached that screws directly into the ram. The die screws into the press head in all versions. | |||
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Use a little Corbin Swage Lube on your fingertips and give the punch a quick wipe of lube, then pick up a case and put it over the punch tip. Adjust the die so it is very high in the press threads. Raise the ram carefully. The rim of the case should just barely start to go into the die as you reach the end of the ram stroke. Lower the die until this point of adjustment is reached, and then lower it just another quarter turn or less. Lower the ram, as necessary to adjust the die, and then raise the ram. Little by little, you should be finding the point where the rim is ironed out cleanly, leaving no ridge behind. Then continue to carefully adjust the die downward, until you can just push the jacket through the tightest part of the die and out the top with one smooth but powerful and rapid stroke. Do not operate the press with the die so low that it takes all your effort to push the cases through! This is not necessary and will only strain your bench mountings and your patience. A firm one hand push will do the job, in a single pass. These little jackets represent a lifetime of free components, so it is worth spending a little time to learn the fine points. Once you have drawn the jackets, you may have to anneal them. One fine point is that the annealing temperature can be critical. If you make a wide open tip or a large lead pointed bullet, you may not have to anneal at all. But if you try to make a small open tip bullet, or even a small lead tip, you may find that the end of the bullet folds over with a little flap of metal instead of drawing to a smooth curve. This is a sure sign that the jacket material is not annealed sufficiently. Actually, annealed may be the wrong word because that implies a dead soft condition. You can just soften the brass to a lesser degree, more of a stress relief heat treatment. If you overheat the cases, they will turn discolored and may become rough on the surface. You can always heat them a little more, but you cannot undo the damage from overheating. Some people use a tuna can floating in a molten lead pot to hold the cases for annealing. I like to use the self-cleaning oven, or a propane torch with one of those fishtail flame spreaders and just heat the cases until they are barely red in a dimly lighted room. It only takes a few seconds to get them that hot. You can do a small group of twenty or so at one time. You can try skipping this, but make one bullet all the way to completion before you seat all the lead cores in those jackets: you may find out that you need to heat a little more. If that happens, your seated cores make it harder to do (but not impossible). If you find that the jackets have circular rings in the shank area, like badly-made cannelures, this is a sure sign that you have overheated the cases to the point where they are rough and dead soft. Then they will not have enough strength to resist folding like an accordion against the pressure needed to shape the ogive or nose. This kind of folding usually happens in the point forming operation, as does the flap of metal that folds at the ogive when the jacket is too hard. Sounds tough, eh? Too soft, and the shank gets rings in it. Too hard, and the nose folds over. But there is quite a wide range between those extremes where the bullet forms very nicely, with barely any suggestion of the little fold lines you would see on all commercial spitzer bullets (less so on round noses) if they were not polished out in a tumbler before being boxed. The ogive curve on the spitzer shaped bullets brings the metal close at the tip and thickens it, and it tends to | |||
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develop lines that look like scratches but are actually folds. This is normal, but not commercially attractive. So, commercial bullets are polished to remove or burnish over this minor cosmetic flaw, and you don't see it. (If you inspect the bullets very closely, you may in fact see some remaining signs.) The Corbin RFJM-22 dies have gone through a number of versions over the years. At one time, we built a tube and disk ejector that slipped over the ram, to strip the jackets off the punch on the down stroke. Now, we make the punch long enough so you can find that point of adjustment to push the jacket all the way through the die at the end of the stroke, and we make the top of the die with a square, sharp junction between the edge of the hole and the die insert. When the jacket mouth passes through the die, the jacket springs back slightly toward original diameter. The jacket mouth becomes larger than the hole, so that when you pull the punch back, the top of the die pushes the jacket off the punch. Of course, it cannot do this if you do not push the jacket all the way through the die. The rimfire case starts with a diameter of about 0.225 or .0226 inches, which is too large because the jacket must be smaller than the finished bullet. To unfold the rim and draw it evenly into a smooth cylinder, as part of the jacket wall, we must reduce the jacket to about 0.219-0.220 inches. This happens to work out very well for a .224 jacket diameter. The punch diameter to fit inside a .22 rimfire case and accomplish this draw needs to be about 0.199-0.200 diameter. By the magic of subtraction, we can see that this leaves a difference of about 0.020 inches, which means that each wall of the jacket must be about 0.010 inches thick. Commercial bullet jackets for .224 caliber are usually made from strip that starts out 0.026 to 0.030 inches thick, with walls that taper forward to perhaps as little as 0.012-0.015 inches at the mouth. But the greater part of the jacket wall is more likely to be from 0.020 to 0.026 inches thick. This means that your free .22 rimfire jacket is about half as thick, in general, as the commercial bullet jacket. It is also made of a higher zinc content brass, having nearly 30% zinc as compared to the 5% to 10% zinc in the commercial bullet jacket. This means it is slightly harder but more brittle, as well as thinner. These factors result in an excellent varmint shooting bullet, with little or no ricochet odds (when the thin, brittle jacket hits the ground, it usually explodes or pops open into a four pointed "star" all the way to the base, even at modest speeds). But the speeds must be kept relatively modest, or else the thin jacket will come apart in flight. I usually recommend that you maintain a velocity of 3200 fps or less. Some people shoot them faster and get away with it. It probably depends on the depth and sharpness of the rifling in a given barrel, and whether it cuts into the thin jacket or irons the grooves without weakening the jacket even further. Making rimfire case jackets is one of those operations where I can honestly say that our smallest hydraulic power press does the best job (the big ones do OK, but they really are overkill). The CSP-1H Hydro-Mite press can push those jackets out all day long and never get tired. For decades, one of our clients has made a nice retirement income building 224 bullets with free rimfire cases, using a manual press. I've tried to get him to go to a power press, but he's happy with three manual presses. I mention this because it shows that you can make a business | |||
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doing everything the opposite of what I recommend and it still works for some people! I generally do not recommend a standard design of .224 bullet for a business, because there are plenty of mass produced .224 bullets that sell for a low price. But if your materials are free, and the price you get just pays your labor, then it must work. Probably by now the ancient fears about fouling, barrel wear, and accuracy have long been settled, and forgotten. I should mention them in case there is still someone, somewhere, who has the idea that fired .22 cases cause any problems in these areas. Yes, once, all these things were issues. The reason: mercuric priming. Fulminate of mercury was one of the earliest of rimfire priming compounds. It is easy to make and gives reliable ignition. But the mercury reacted with brass cases, and made them brittle. Therefore, it wasn't long before center-fire cases, which could be reloaded easily, were the cause of a demand for non-mercuric primers. Otherwise, the cases would be too brittle for reloading, and reloading is one of the major benefits for center-fire cases. But rimfire cases are almost impossible to reload. You'd have to somehow get the dent out where the firing pin hit the rim, or else that would be one spot where you'd get unreliable or no ignition the second time around. And you would have to figure out how to make a priming compound slurry and spin it into the rim again, evenly deposited in just the right amount. It could be done, but the expense and trouble just doesn't seem worth the result, not to mention the danger of blowing one's fingers off or worse, while mixing up priming compounds. So, rimfire cases are not reloaded by most shooters (in fact, I've only met one who even tried it). That meant mercuric priming gave no particular problem to shooters of rimfire cases. Who cares if they get brittle after being fired? They are thrown away or left on the ground, anyway. Except some few brave souls began to pick them up, and turn them into jackets for .224 center-fire bullets! Now you can see where the fouling, accuracy, and even barrel wear issues came about, right? Until the late 1960's, there were still mercuric primed .22 rimfire cases being made. Since then, issues with health (from the mercuric vapors mixed in the powder gas, fired in indoor ranges, where lots of kids learn to shoot with rimfire rifles) have largely gotten rid of any mercuric priming. Tin-based priming compounds replaced the mercury compounds. For decades, the problem has been buried, but not forgotten. People still remember and talk about the old days when fired .22 cases made into bullets used to flake off in the barrel, or come apart in midair for no particular reason. Just because it has not happened for thirty or forty years is no reason to let go of a good rumor! That takes care of the fouling and accuracy issues. A fired .22 cases made into a bullet is actually less likely to cause fouling than a commercial jacket. It has more zinc, which makes it harder, slicker, and tougher, and less likely to come off in the bore. Accuracy is well known by now. Some brave souls even won benchrest matches with fired .22 case bullets. If you select high grade brass and sort them into lots, fired from the same gun, such as those you might pick up at your indoor | |||
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target range after someone you know, or yourself, has finished a match, then you can get just as good a quality including jacket run-out as the best commercial jackets. Ely Club ammo used to be the best for quality rimfire case jackets. But flyers do happen when you pick up cases off the ground, and some were fired in different guns, some were dented more or less than others or even cut through by the firing pin, and some are different brands. The stress history of the metal will change it slightly, even if you anneal it. The firing pin dent, which is ironed out and virtually invisible in the final bullet, might be an issue with extreme accuracy, and certainly will be if it varies from one case to the next. Cases cut through by the firing pin probably will not shoot to the same point of impact as those not cut through. For all these reasons, I would not recommend going to the Nationals with winning in mind if you use .224 bullets made with fired .22 cases. But I would expect a good shooter with a winning rifle to do very well, in any case, and probably to win most of the local matches. Rimfire case bullets are much better than they might appear to the casual reader. In fact, they can be surprisingly good, better than many factory bullets. It depends on the care taken in making them, and the quality of the dies used to form the bullets. A clever and analytical reader might at this point say, "This is all very fine, but I think you skipped over the issue of barrel wear: the jackets may not be brittle any more, but you said they were harder and tougher than commercial jackets." Right you are. The additional zinc content makes the jacket harder by a modest amount. It is still far softer than the barrel, far softer than a steel jacketed military bullet. But it also is half the thickness, so it pushes inward much more easily than a commercial jacket. When the rifling (of about 0.004 inch height) pushes against the rimfire jacket, is meets the resistance of a mere 0.010 inch thick wall, instead of the typical 0.026 to 0.030 wall of a commercial jacket. Subtract the rifling land height from a commercial jacket wall, and you still have 0.022 to 0.026 inches of metal under the rifling groove in the jacket, supporting it and pushing it against the barrel. Subtract the 0.004 inch land from the 0.010 rimfire case jacket, and you have a mere 0.006 inches of support. The difference in metal toughness is not nearly enough to make up for this, and the rimfire jacket flexes under the rifling to a much greater degree with a resulting lower friction and wear rate. Not only that, but the coefficient of friction of the high zinc content alloy is lower than with the typical gilding metal or commercial bronze jacket (5% or 10% zinc/copper alloys are used for most bullets, with the "commercial bronze" being a total misnomer that is in standard usage anyway: there is no gold in gilding metal, no tin in commercial bronze because it is not bronze but just another brass ratio). That is, the metal surface is "slicker" and causes less heat and wear as a result. Bottom line: rimfire case jackets are easier on your barrel, just as accurate, and probably foul less, than commercial jackets. Their main drawback is that they are thin and therefore cannot be driven so fast. Likewise, their thinness makes them unsuitable for big game. But most of us are not that good a shot or a stalker to allow us to use a .224 for big game and still call ourselves good sportsmen. | |||
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(Some are, and I applaud them, but the first time they lose a deer or an elk that a medium or large bore rifle would have taken cleanly, they should have the good grace to quit using a small bore rifle.) Their advantage over commercial jackets is cost: they are free. If you want to make a good varmint bullet that blows up like it was going 4,000 fps when it hits at a mere 3,000 fps, then that is another advantage —not to mention how much fun it is to out-shoot your buddies, who paid good money for their bullets and refuse to believe that anything you can make from free materials could possibly work as well or better! | |||
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8. Making Lead CoresLead is the most commonly used core material for bullets. What is a core? We call the material that fills up the jacket a core, but even if you don't use a jacket, the piece of lead that will form the swaged bullet is also called a core. Swaging requires that you prepare the core so that it will fit inside the swage die. You can't shove a huge billet of lead into the die, of course, but you can melt the lead and cast it in a multi-cavity "core mould" to form the right diameter and length of ready-to-swage cores, or you can simply purchase lead wire. With Corbin power presses and optional extruder die, you can make your own lead wire. Lead Wire (LW-10)Lead wire in 10 pound spools, LW-10, is available from Corbin in sizes from .125 to .430 inch diameter. Lead wire is by far the most convenient and time saving way to produce bullets. It eliminates all of the risk from hot lead. All you do is chop the lead wire into the correct lengths using a tool called a "core cutter". Since Corbin lead wire is 99.995% pure, you can use it as a sample for hardness testing (Bhn 5.0). It is provided in single rolls, or in case lots of four rolls for a discounted price (provided the four are the same diameter). Lead wire comes in .125, .170, .185, .218, .247, .275, .312, .340, .365, .390, and .430 diameter. It is provided in pure form only, not as alloys. Alloyed lead can be cast, but it is more difficult to extrude. In most cases, there is no advantage to hard lead for swaging. Soft lead is more dense, expands better without breaking apart, and bonds very well to the jacket. Four cavity core mould (CM-4)If you prefer to cast lead cores, the CM-4 four-cavity core mould can be adjusted for any practical weight of core by setting the displacement of four pistons in their matching, honed steel cylinders. It is rather like a straight-line automobile engine: the sprue cutter is a long handle similar to the engine head; the four pistons slide up and down inside of matching cylinders to eject the cores as soon as you rotate the sprue cutter to one side; the cylinders are held firmly in a block with a long mounting handle, in the manner of a car's engine block. The pistons rest upon a "rest plate" which in turn is supported by two threaded rods, but loosely, so it can move up and down. There are two pair of nuts on each of the rods, which form a stop that adjusts the position of the rest plate in the down position. This sets the piston displacement, which in turn sets the weight of lead core you will make in each cylinder. The CM-4 core mould mounts to your bench with two screws so the pistons and cylinders hang over the edge. I like to mount it on a short piece of two by four wood, and clamp this wooden block in a bench vise so the mould is held parallel to | |||
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the floor. In fact, by mounting the mould with a common door hinge instead of directly to the bench top, the motion of opening the sprue cutter can also be used to tip the mould over so the cores fall out into a box. You do not need to cut the cores which are cast with a core mould, because core moulds are designed so that you can adjust the length of the core as it is cast. Core moulds let you take advantage of existing supplies of scrap lead, provided it isn't too hard for the kind of swage dies you have. Any hardness of lead can be swaged, but you need type -H dies for alloys over about Bhn 10-12 hardness to avoid die breakage. Generally there is no advantage to hard lead for swaging, because swaging gives you so many other ways to eliminate bore leading. The CM-4 core mould comes in standard diameters of .185, .210, .224, .247, .280, .312, .340, and .365 inches. Smaller diameters are not practical to cast (use lead wire or an extruder die). Larger diameters can be made with the CM-3 Magnum core mould. The weight is adjustable. Custom diameters can be made to order, for an additional amount reflecting the extra labor cost of making a special single production set.
Magnum core mould (CM-3):The CM-3 Magnum core mould is more than twice the size of the CM-4, and can make up to half-inch diameter lead cores. The stock sizes are .390 and .430 diameter, but other sizes can be made to order. Like the CM-3, the Magnum core mould is mounted to your work bench by two screws, and hangs over the edge. It is charged with hot lead from a dipper. If you use a bottom draw pot, use a ladle and fill the ladle from under the pot, like a mould, then transfer the hot lead to the top of the mould. Do not try to use the mould as a hand-held tool. It was not designed for this. It is much faster to operate when mounted. Precision Core Cutter (PCS-1):Corbin core cutters mount to your bench, so that the lead wire is fed straight down, into the top of the cutter. A stop screw is adjusted to stop the wire at the desired projection below the shear line of the cutter. This is what gives you the desired core weight (plus a little for final adjustment in the core swage die or LSWC-1 die—usually 2 to 5 grains more than desired weight is enough to assure a good final weight control). Core cutters quickly shear the lead as you feed it down into the device and move the handle back and forth with the other hand. Usually it is easiest to cut about eighteen inches of wire, or whatever amount will stand up straight in the air without sagging over to one side. Then insert this length into the cutter and let gravity feed it down as fast as you can chop off pieces. A gentle support with one hand is usually all it takes to give good feeding. You can also mount rolls of lead on a simple pipe stand, so they feed down into the core cutter and lengths can be pulled off quickly. | |||
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The PCS-1 core cutter is designed to use PCS-1D die inserts, which look very much like drill bushings. These half-inch diameter hardened steel dies come in pairs. One mounts in the top bar of the cutter, and the other mounts directly under it in the moving arm. The standard sizes are .125, .185, .218, .247, .312, .340, and .365 (size of wire that easily slips through the hole, not the hole size). Each cutter comes with one set of dies for a given caliber of your choice, and you can add other standard sizes at low cost, or order custom made sizes at a reasonable price. If no size is specified, we will send whatever size we feel is appropriate based on our best guess of what you plan to do with it, usually based on the caliber of your other orders. Magnum core cutter (PCS-2):For cutting lead wire diameters larger than .365 inches, the PCS-2 Magnum Core Cutter is recommended. It is nearly three times the size of the PCS-1, and uses specially made individual hardened die inserts, PCS-2D, for each range of wire sizes up to 0.5 inches. This larger cutter can also handle sizes down to .185 inches but the minimum length of core is half an inch, because this is the thickness of the steel frame holding the dies. Thus, for lighter weight cores in the .224 or smaller caliber, and for light cores in 9mm and .38 caliber, the PCS-2 cannot be used. If the core can be at least 0.5 inches long, it works very nicely and is highly recommended because of its great strength and leverage. But if you need cores that might be shorter than 0.5 inches, the PCS-1 is the correct choice provided that the core diameter can be .365 inches or less. Stock sizes of dies are .365, .390, and .430. If you do not specify the diameter of die, we will send either .390 or .430, because these are the most popular for the large cutters. Dies can be custom made in any diameter. Lead Extruder Die (LED-1):The CHP-1 Hydro-Press and the CSP-2H Hydro Junior can be used to extrude lead wire in virtually any diameter. Only pure, soft lead can be extruded with this die set. The die is actually part of a kit that includes two billet moulds (for casting soft lead into cylinders that fit inside the extruder die) and a mould base, the die, three sizes of die inserts for different wire sizes, the extruder punch and a lock nut. The die screws into the top of the press, replacing the floating punch holder. The punch screws into the press ram. It is designed to be easily removed and replaced, to facilitate loading the lead billets up into the die. First, mount the mould base on a sturdy bench. Then push one of the billet tubes over the base, and pour hot lead into the tube. Wait until the mould cools slightly, then pick it up with a padded glove or other heat-resistant material, and give it a rapid shake to slide the lead out. As the lead cools it will shrink away from the billet tube and come out easily. | |||
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You can set the lead-filled tube aside if the lead won't slide out yet, and fill the second tube. By the time you remove the second tube, the first one will probably be cool enough for the lead to come out. Place the empty tube back on the base and continue filling and rotating tubes until you have made enough. After the lead has cooled enough to handle safely, you can then spread a thin film of Corbin Swage Lube on the surface of the cylinder, and push the lead cylinder up into the bottom of the extruder die. Replace the slide-out punch, and align it with the die (the lead will probably rest on the punch end). With the proper diameter of die insert in the top of the die body, and the retainer bushing screwed firmly down against the die insert, start the ram moving upward. The punch should smoothly enter the die mouth and start to compress the lead. The pressure should be turned up until the lead starts to extrude from the top of the die. Usually this takes 1,800 to 2,000 psi on the gauge. Do not place any part of your body over the top of the die. Lead may be expelled with great force if any air is trapped in the die. When the lead wire starts to move, it will heat the die insert, and this will in turn cause the lead to move even faster. In a second or so, the lead will spurt out rapidly and will come out very hot. Do not touch it without using a glove. The entire billet should extrude in a few seconds. When the lead is extruded, lower the ram. Loosen the retainer in the top of the die, and remove it. You should be able to pull the die insert out of the die body by grasping the lead wire and pulling up. Push the lead back through the die just far enough to allow you to clip off the enlarged flange of lead remaining. Then reload the die and extrude another length of wire. Do not try to join the wires together by loading before the last billet is cleared from the die. It will make a bad joint that comes apart later. You can specify any three diameters to come with your extruder, from our standard sizes. Or you can order a custom diameter of LED-1D extruder die. Additional billet mould tubes can also be ordered for higher production. If you want to extrude hard alloys, we can build a custom extruder with a smaller bore, which generates higher pressure with the same ram thrust. Some alloys, however, are just too hard to extrude reliably. We will need a test sample before we know if your alloy will extrude. Core accuracy (weight control):There is no difference in the accuracy of bullets made with cast or wire cores, if you process the cores with either a core swage die or the LSWC-1 style of die (both have bleed holes to adjust the core weight precisely). In theory, lead wire would be slightly more precise because it has been extruded at high pressure and probably does not contain any air bubbles or voids, but the core swaging operation takes care of that in any case. If you do not use a core swage or LSWC-1 die to adjust the core weight, then your core variation should be less than 2% of the total bullet weight with careful casting or cutting technique. Bear in mind that percentage of total bullet weight is what matters, not absolute weight difference. Five grains makes no practical dif | |||
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ference in a 500 grain bullet, but it is very significant in a 50 grain bullet. Swaged cores typically are held to less than 1% of total bullet weight, and perfectionists achieve less than 0.5% tolerances. This could be any amount of grains, of course. With nearly any set of swage dies, the first die should be a CSW-1 core swage. This die extrudes a small amount of lead through bleed holes in the die, leaving a fixed volume which you can set with the punch holder (the distance between punch ends controls the volume, and thus the weight, of the core). The core swage only works if you go to the end of the stroke each time, so that a fixed distance is established between the top and bottom punch. This in turn established a fixed volume within the die. Any additional volume of lead is extruded through the bleed holes. Holding the pressure for a constant amount of time at the end of the stroke also helps make more accurate weights. Double swaging adds a tiny bit more precision to the weight control process, but is usually overkill except for perfectionists (you know who you are!). In a power press, the top of the stroke can be set by an electronic sensor, which shuts off the fluid power flow when it sees the ram guide plate. This is a convenient way to adjust the press for the shortest stroke (ram travel) that will do the job, making the job go faster than if you used the entire stroke. But there is a slight variance in the final stopping point, due to differences in the trip point of the sensor, ambient temperature changes that affect both the electronics and the hydraulics, inertia in the hydraulic system, and other physical causes. To eliminate these sources of weight error, you can either use the entire stroke and stop the cylinder against the end of its housing (a positive, unchanging position) and use the pressure reversing mode to control the press stroke, or you can get the Positive Stop Punch Holder, FPH-2-H. This punch holder is made of hardened steel, drilled all the way through the center. The punch drops in from the top, and rests on a thick ledge at the bottom of the hole. A long, hardened steel threaded rod is then screwed into the top of the holder. The position of this rod controls how far the external punch can travel back up in the holder. The punch holder is then adjusted so that the face of the swage die actually contacts it, and stops the ram movement in the upward direction. The punch holder is designed to withstand all the force that the press can generate. By stopping the ram this way, there is nearly perfect consistency in the volume left in the die at the end of the stroke, and thus nearly perfect core weight. So why don't we supply this holder instead of the regular one? It is much slower to load the punch, and for most purposes, you do not need this degree of weight control. But, if you do need it, the optional FPH-2-H will deliver. Core size (diameter):Because there are differences in jacket walls depending on how you make or where you acquire the jacket, it isn't possible to absolutely specify a proper diameter for each caliber. The rule of thumb is that the lead wire or cast lead core should drop easily into the jacket, to the bottom. If it contacts the jacket wall before that point, then air can be trapped behind the core. If you seat the core you can compress the air to 30,000 psi, and it may be trapped in the base, but I've seen | |||
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cores pop out of the jackets with considerable force after the seated cores and jackets have been left on the bench for a few minutes, especially if the sun happens to fall on them through a nearby window! The right size of lead wire or cast core is that which fits easily by hand into the core swage die (CSW-1) or the LSWC-1 (for lead bullets) and yet isn't too long and thin to fit completely into the die prior to swaging. The right size of core swage is whatever makes a core that drops into your jacket all the way. So you can see that the core size, for jacketed bullets, fits the core swage, and the output of the core swage fits the jacket. In general, if you use the jackets most often available for these calibers, here is a table of core sizes, core swages, and calibers that would work, assuming normal or thinner than normal jackets (extra thick jackets require smaller cores):
CALIBER WIRE SIZE SWAGED CORE SIZE .142 .100 .105 .172 .125 .130 .204 .170 .173 .224 .185 .191 .243 .185 .191-201 .251- 257 .185 .191-220 .265- 277 .218 .220-224 .284 .218 .230-235 .308-338 .247 .249-257 .355-375 .312 .318-257 .400-412 .340 .350-370 .429-458 .365 .370-380 .475-505 .390 .400-420 .511-998 .430 .435-550
Please bear in mind that actual lead core diameters depend on the jacket wall thickness, so that you might need the next standard smaller size of wire if the jacket wall is thicker. Likewise, if you plan to make lead bullets without a jacket, then use the lead wire size that is at least .005 inches smaller than the caliber. For instance, a .452 or a .458 lead bullet would use .430 wire, but a .429 lead bullet would need to use the .390 size instead. Lead wire larger than .430 is too difficult to coil, so it is either supplied in straight lengths or you would use a core mould. In fact, when the required core is larger than .430 the cost factor per bullet favors casting your own cores. When the core is below .218 inch diameter the cost factor favors lead wire instead of casting. The convenience and time saving of lead wire is a strong consideration regardless of diameter and cost per bullet. If you want to make a paper-patched .45-70 bullet, and your bullet diameter with the patch applied is to be .458 inches, using 0.0025 inch thick paper, this would require a bullet of .448 inch diameter before patching. Why? Paper patching material is generally wrapped around the bullet twice, so the edges just come together on the second wrap. Looking at a cross section of the bullet, then, you would have the bullet diameter, plus four thicknesses of | |||
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paper. Generally you would want the total diameter to fit into the bottom of your rifle grooves. A .45-70 bore generally has a groove-to-groove depth of .458 inches and a .450 inch bore hole, for .004 inches of rifling per side. Subtract four times the paper thickness from the barrel's groove-to-groove diameter, and this gives you the correct bullet diameter to make. In this example, .458 less 4 times .0025 gives us .458 .010 or .448 inches for the bullet. You can use .390 lead wire, since this is the largest practical coiled diameter available. But if you were to have an extruder made, or a core mould, it would be even better to use .440 to .445 inch diameter cores. Any diameter that fits into the die nicely and is not too long, at the weight you desire, to be enclosed completely in the die before any pressure is applied, will work. The upper limit of core diameter is whatever fits easily into either the jacket, or the die (for lead bullets). The lower limit is whatever just fits completely in the die without sticking out the die mouth, and allows at least one caliber of length for inserting the external punch before any pressure is created. If you use too long and thin a core, it will contact the external punch before the punch can be aligned at least a full caliber depth in the die. This can cause the punch to be tipped or bent when you apply pressure to compress the core. Any core diameter between these two extremes works, but the closer the core is to finished diameter, the less folding and wrinkling takes place and the less work it is to compress it smoothly and evenly. Core lubricationWhen a core is swaged, it is first lubricated with Corbin Swage Lube, simply by applying a drop to your fingertips and rolling the core back and forth once or twice as you pick it up. No detailed ritual is required. A thin film of lube transferred to the lead surface is sufficient. If you want to lubricate a large quantity, put half a teaspoon of Corbin Swage Lube inside a clean tumbler and load it with as many cores as your tumbler will spin without overloading it. Then turn it on and let them tumble for half an hour, or until all the cores are evenly lubricated. The film of lube greatly reduces swaging pressure, helps insure long die life and eliminates lead fouling of the die and punches. Once you have swaged the cores, the lubrication must come off before you put them into jackets. Corbin Swage Lube will wash off by boiling the cores in a pot of hot water with a little strong detergent added. In fact, just the hot water works reasonably well. I like to use boiling water, because the heat quickly drys the cores once you pour them out onto an old towel to dry. You don't want them to sit around very long with moisture, because they will tend to oxidize, and this prevents a good core to jacket fit. Swaging lubricant is not the same as bullet lubricant. Swaging lube acts as a high pressure film between the die and the bullet, reducing friction and lowering the pressure needed to form the part. It is not designed for use under high temperature, and it is designed to be easily removed in solvents or water. It is clean, and is normally quite safe to handle (in rare cases someone may be allergic to the castor oil or lanolin components). Corbin Swage Lube is made from medical grade compounds designed for cosmetics. | |||
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Swage Lube forms a hard lacquer film when heated to annealing temperatures for copper jackets, however. This film prevents Corbin Core Bond from working, so be sure to wash off the lube from any bullet jacket and core which are intended to be bonded using the Corbin Core Bond process. Core bonding is a process of melting the lead, within a jacket, in the presence of the liquid Core Bond. The Core Bond lowers the surface tension of the melted lead so that it can easily penetrate into the copper jacket, forming an actual alloy that is shallow but stronger than solder or glue by a considerable margin. The advantage of the diffusion junction between the lead and jacket is that there is a gradient of tensile strength created, instead of a sharp junction between the 1000 psi lead and the 18,000 to 22,000 psi jacket material. A sharp junction, such as exists under a layer of solder or glue, acts as a point of concentration for sudden stress. When the bullet strikes, a tremendous amount of stress is created within the bullet in a very short amount of time. The force is channelled to areas where there is a big difference in tensile strength, and tends to separate them. When the tensile strength of the materials flows through a gradient, becoming different over a distance rather than suddenly, the force of impact can flow with it, and cause less concentration at that point. The bottom line is that a bonded core bullet can usually be shot inside out and still retain nearly all of the core, whereas glued and soldered or plain unbonded bullets often separate at the junction of the core and jacket. Microphotographs taken of bonded jackets, under a scanning electron microscope, show atoms of lead within a one to two micron depth beyond the inner surface of the jacket wall. You don't get that with any kind of glue or other surface adherent bonding. That is the technical reason behind the fact that 90% of the world's custom bullet makers who build hunting bullets use our bonded core process. It is fast, low cost, and it works better than the alternatives. | |||
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9. Swaging with a Reloading PressSome Corbin dies are designated type -R. This stands for "Reloading Press", and means that the die set was designed to fit into a regular single-station, slotted ram reloader with standard 7/8-14 threads. Any of our tools that have the -R suffix are meant for use in a reloading press. The dies screw into the press head, like a reloading press die. The external punch snaps into the slotted ram like a shell holder. Why would you want to use dies modified for use in a reloading press, when swaging presses are so much faster and more versatile? The reason is economic: if you already have a reloading press, and don't wish to make benchrest quality bullets but will settle for a reasonably good bullet (about equal to or slightly superior to standard factory bullets), then you might want to use the -R dies. Disadvantages of using a reloading press1) The pressure required for swaging larger calibers places a severe burden on the unhardened screw-stock rams used in most reloading presses, which can cause undue wear and distortion of the ram. Most reloading presses are not equipped with any bearings, so the pivot pins, ram, and other moving parts are placed under high frictional forces when harder alloys or larger calibers are swaged. Therefore, Corbin reloading press dies are built only for use with pure soft lead cores. If you use alloy lead, the pressure will be considerably higher, and could break the die or damage the press. 2) A reloading press has no built-in floating alignment, and in fact is generally quite sloppy compared to the alignment of an actual swaging press. This is fine for reloading because there is no real need for high precision alignment: the shell holder and fit of the cartridge case both are so sloppy that there is no gain in making the press highly aligned between head and ram. But in swaging, better bullets result from precise alignment of the press head and ram. The forces are considerably higher, so that a little off-center torque can make a difference in punch life and bullet quality. The lack of high alignment precision means that certain styles, such as the rebated boattail, are not available for the reloading press. 3) A reloading press has no built-in way to eject the bullet from the swage die. You need to use a small plastic mallet and tap the plunger provided with the swage die, to knock out the bullet (and catch it with your other hand). Actual swaging presses have automatic built-in ejection when used with dies designed to fit the ram, and are considerably faster to operate. 4) A reloading press has less than half the leverage of any Corbin swaging press, since it must use about four inches of ram travel. Swaging only requires about two inches, for most of the calibers and styles that can be made by hand. | |||
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Therefore, by simple physics we can double the force with the same amount of handle travel. This makes swaging with a real swaging press far easier (less than half the effort required). 5) A reloading press does not generally have any bearings, so they tend to wear and become quite loose under heavy loads. Corbin swaging presses such as the S-Press or the Mega-Mite travel on needle bearings with the rams guided in long oil-impregnated bushings. This extends the life and lowers the friction, which in turn reduces your effort for a given amount of thrust output. Most loading presses have sufficiently heavy frames but rather weak, soft screw-stock rams and pins which are sometimes reduced to half their visible diameter inside the hole, as safety links, to prevent damage to the rest of the press. Corbin swaging presses use full-diameter, hardened alloy steel links which turn inside high-pressure bearings. The swaging press can be physically smaller and yet still be considerably stronger, especially those which built from alloy steels. The S-Press, for instance, uses 130,000 PSI steel, whereas the most popular large reloading presses advertise "35,000 PSI tensile strength" for their cast iron frames. Available tooling for reloading pressesOne type of -R die comes in any standard caliber from .224 to .540 inch diameter for soft lead, semi-wadcutter style bullets (that is, bullets which have their noses made entirely from lead, and which have a small step or shoulder between the nose and the shank). These dies are called the "Pro-Swage" dies. They are only made in the design of a core seater, not point form, lead tip, core swage, or lead semi-wadcutter. You can get flat base, cup base, dished base, or hollow base styles, or the Corbin "Base-Guard" base. The internal nose-forming punch is available in Keith, 3/4-E (a typical pistol round nose shape), 1-E (a typical Winchester or Sharps rifle nose shape), target wadcutter, button-nose wadcutter, hollow point (which is then followed by another punch to get both the HP cavity shape and the nose curve shape), auto-loader (a sort of bell-shaped round nose that feeds nicely in most autoloaders), and conical. We also build -R dies in two, three, or four die sets to make jacketed rifle or handgun style bullets. The two die set normally consists of a CS-1-R core seating die, and a matching PF-1-R point former. The three die set adds a CSW-1-R core swage die for more precise lead core weights. The four die set adds a LT-1-R lead tip forming die for a professionally finished lead tip. These are available in the following calibers, in the 6-S ogive shape: .224, .243. They are also available in 3/4-E ogive shape (handgun or carbine style) in these calibers: .251, .308, .312, .314, .355, .357. Please note that you can make a .30 caliber rifle bullet in these dies, but only up to about 150 grains total weight, and only with the various wadcutter, semi-wadcutter, or round nosed ogive shapes. This is ideal for carbines and handguns, but isn't suitable for long range match competition. For that you need to step up to one of Corbin's swaging presses and the dies to fit it. If you use type -S dies, there is no difference in die cost. The only difference is the swaging press, and it makes | |||
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so much difference that you will surely thank me later if I am able to convince you not to try making the longer, more pointed bullets with a reloading press. Every tool and process has its practical limits. I know that other people have made designs that I would not recommend, and some may even be trying it as you read this. I suppose the thing to do is scan through the old gun magazines and look at all the outfits who used to make swaging dies. You'll see Corbin tools, of course, but you'll also see a number of other brands offering those designs which are absent in our line. Try to find those other firms today. They are not in business now, you say? Really! And they made the designs that Corbin does not recommend? Perhaps there is something to be learned from that. There will always be a few new comers touting the same reinvented square wheel, who will shine in the spotlight of publicity and win a few converts, then suddenly disappear when enough of their work comes back to bite them. It is always sad to see someone fail in business—which is why I am happy after talking to my clients (with their 98% plus success rate). There is always a tiny but fairly steady trickle of challenging phone calls and letters from people who have glowing stories about the use of design ideas that we long ago ruled out as a reliable good value to our clients. Honestly, after decades of patiently explaining why they are not good ideas in spite of the fact that Cousin Joey had great luck with one or some temporarily famous shooter or mechanic is getting rave reviews from some niche of the shooting fraternity at the moment, I really don't care to spend any time debating it. There will always be dark corners where long term value and scientific fact is excluded by blind exuberance. A goodly number of these ideas revolve around using a reloading press in some way that is technically possible, but not a good long term value. The lure of getting by cheaper is strong enough to overpower good reasoning, sometimes. I am not doubting that some of the ideas work, at least from time to time, in specific situations, when run by very careful operators. But the reason we do not offer them, and would prefer not to be "talked into" making special exceptions, is that there is a better way. Better might mean more cost effective, giving you the same or better value, as with using solid carbide versus a high carbide die steel in non-automated presses. Better might mean less likely to stick, jam, or break if a person gets forgetful or careless about lubrication, alignment or pressure, as with our standard ejection pin sizes. Or, better could mean equal in final result but standardized for replacement parts, service, and knowledge accumulated to help you with various situations. Sometimes, better means it actually works every time, consistently, and has enough history behind the design to warranty the product, even if there seems to be a cheaper alternative or one with fewer steps. Still, we do a lot of custom work, and take each request on its own merits. Nearly all of these are better done with the -S or -H dies and presses, however. | |||
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Reloading presses suitable for swagingFor the fired .22 long rifle cases drawn to make .224 or .243 bullets, you can use almost anything that will accept the dies and the punches. The little RCBS Junior press was one we used to demonstrate swaging at gun shows, in the old days. It doesn't take a big press to swage smaller caliber bullets. You can use Rockchuckers or Pacific Multi-Powers or C-H Champions, of course. They are sturdy, standard design presses. Any press with a single station head and ram, which accepts standard RCBS-type button shell holders, and has a 7/8-14 threaded top, with a physical layout similar to the Rockchucker, should be fine. The ones you can't use are those which have special mechanical shell holder devices instead of a slotted ram, or those which have a handle that swings over the top of the press, like the Bonanza Co-Ax press (the handle parks itself right over the die, where you need to tap on the swaging die's knockout rod to push the bullet out of the die). I prefer not to use turret or progressive presses because of inherent alignment and strength problems. Swaging puts a lot of strain on that pivot! Aluminum and light duty reloading presses may be usable for smaller caliber swaging, but are not ideal for it. The popular Dillon progressive reloading presses are not made for bullet swaging, and could be damaged if you try. Most progressive or multi-station presses are best used for their intended purpose, not swaging. This is in no way a criticism of the press. Most presses that sell in good volume over a long time period are good, solid presses, or else people would soon find out and quit buying them. The lightweight Lee presses are very sturdy and entirely suitable for their intended jobs. But swaging places unusual forces on the top of the ram, and on the pivot pins, links, and toggle. Designs that work just fine for reloading may not last or provide enough alignment and rigidity for swaging. I wish it could be otherwise, because it would simplify my work considerably if I didn't have to design and build swaging presses, and could just concentrate on making the tools and dies. We are of the same mind when it comes to making the equipment as affordable as possible: I could interest even more shooters if bullets could be swaged with a wine cork press or a garlic press! Unfortunately, neither of these presses is suitable for reloading or swaging, and many reloading presses are not suitable for swaging (although with minor changes any of them could press garlic). Types of dies suitable for a reloading pressCorbin makes virtually every sort of bullet and jacket reducing die in the range of .224 to .458 in the -R type (such as the BRD-1-R to turn a .357 into a 9mm, or the JRD-1-R to draw a .452 jacket into a longer, heavier jacket for a .40-65 bullet). These are discussed under the "Draw Dies" chapter. We also make type -R draw dies to turn fired .22 rimfire cases into .224 or .243 caliber jackets, and to turn fired shotgun primers into .25 pistol jackets or partitions for use in .30 caliber jackets. | |||
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Gas checks can be punched and drawn from flat copper strip (.030-thickness, 1-inch wide strip is available from Corbin). The tool to accomplish this is called the Gas Check Maker, or GCM-1-R. It consists of two dies, a blanking die that punches out a round circle of copper, called the disc or coin, and a cupping die that turns this disk in to a short-sided cup and finishes the gas check. I can make this die set for a reloading press, but it works better (less effort, more precision) in our S-Press. Although gas checks are useful for cast bullets, the Base Guard is even better for swaged bullets. It does everything that the gas check is supposed to do in protecting the bullet base, and in addition, helps to keep your barrel clean by actually scraping fouling out of the bore with each shot. The Base Guard is made from the same material as a gas check, but takes only one stroke in a single die. In a reloading press, you can use the BGK-1-R Base Guard Kit. This is a single die and punch, with a slot in the side of the die through which you pass the inch-wide strip of copper while you stroke the press up and down in a short stroke. The punch never actually leaves the die, but simply drops below the slot so you can move the copper strip. Then you raise the punch and poke out a new disk, with a hole through the exact enter. This small hole allows lead to be extruded through during the swaging process, to form a rivet head, holding the gas check in place but allowing it to turn with the rifling (unlike a gas check, which is clamped to the bullet so that if the bullet "skids", so does the gas check). Bullet jackets can be trimmed to exact (and adjustable) length using the ET-1-R die set. This is an "Expand/Trim" type of die, which pushes the existing jacket up into a 7/8-14 threaded die that has an adjustable stop screw in the top. The jacket contacts the end of the stop screw, and is held from moving any further, while the punch (in the press ram) continues upward. The punch is made with two diameters, joined by a relatively sharp angle. The smaller diameter, on the tip, is of relatively short length and represents the minimum length of trim possible. The shoulder does the work. When the jacket comes to a stop and the punch continues upward, the shoulder is forced into the jacket mouth and expands the jacket until the shoulder finally reaches the die mouth. The jacket is pinched between the mouth of the die and the shoulder of the punch, and is cut through. Since you can set the length anywhere you wish, nearly any length of jacket can be cut shorter. The trimmed jacket "tube", which is expanded to a larger diameter, is either stripped off the punch by a tube and disk around the punch, or in some designs the jacket may be split and simply fall off by itself. Actual bullet swage dies include the PRO-1-R Pro-Swage design, and the -R type swage dies that make up the two, three, and four die sets for spitzer and round nosed rifle and handgun bullets of the ogival type (no shoulder). The Pro-Swage DieThe Pro-Swage is normally used for paper-patched bullets in rifle calibers, so we supply it with a cup base and a 1-E round nose ogive punch for rifle calibers unless you specify something different. A popular use of the PRO-1-R is for centerfire pistol and blackpowder rifle Base-Guard bullets. Generally, a pistol swage set would | |||
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be supplied with a Keith SWC nose style and a BG base style unless you specify something else. The Base-Guard base punch can be used without a Base-Guard disk. It simply creates a small rivet head in the exact center of the bullet base, which hurts nothing (and serves to identify your bullet among others recovered later). A die designed to make lead bullets may also be used with gas checks. Base-Guards are much more effective at keeping the bore clean, however. Once you've used Base-Guards, it's doubtful you'd ever go back to gas checks. If you wanted to use the same die for gas checks, half jackets, or three-quarter jackets, you can do it without any change in tooling. If you don't want the little bump on the bullet base that results from using the BG punch, just order a flat, cup, or dish base punch and use it instead. The PRO-1-R die itself is threaded 7/8-14, so that it fits the reloading press top. The upper half of the die is screwed onto this hardened 7/8-14 body in a semipermanent way (held with a thread locking compound). The top of the die is threaded for an adjustable bushing that can be removed to replace the internal punch, which is held captive within the die body by this bushing. A knockout rod in the top of the die pushes the internal punch down (using a plastic mallet or length of wood as a hammer) to drive out the swaged bullet. The internal punch is usually the nose (we can make it the base if you prefer, but you have to keep track of it for future punch orders and make sure to specify "internal" punch). Other -R type bullet swage diesThe -R type core swage die (CSW-1-R) is actually made the same as a core seating die, without bleed holes in the die itself. The diameter is smaller than the same caliber of core seating die, of course, so that a lead core can be swaged to fit inside the jacket, which in turn fits inside the core seating die (CS-1-R). Lead weight is adjusted by using an external punch with a hole through the center, so that lead can be extruded through it. The lead goes into the ram slot, just like a spent primer, except that it may remain attached to the core like a thin lead wire antenna. This is easily snipped off with a pen knife or nail clippers. The reason that a -R type core swage does not have bleed holes in the die itself, as the -S and -H dies do, is because of the geometry of the typical reloading press. Unlike a swaging press, which has a ram stroke that stops considerably short of the press head, leaving room for the die, a reloading press ram is made to stop just below the press top. In order to use the end of the stroke (both for maximum power and also as the positive stopping point necessary to establish constant weight from one core to the next), the -R die cannot be adjusted so that the die extends below the press head. The die is positioned in the middle of the press threads, in fact, so putting bleed holes in the side of the die would spurt lead directly into the threads! Decades ago, I made core swage dies with angled ports and reduced lower diameter to clear the threads and extrude lead at about 45-degrees to the bore, but the dies were not successful in the long run. Using hard lead has never been recommended with -R dies, but it positively blew these angled port dies to bits | |||
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(although nothing flew around, since the pressure was instantly relieved when the die fell apart). The -R core swage die works reasonably well, but it does require an extra step of snipping off the single wire extrusion. Core swages used in our swaging presses automatically shear off the extrusions on the down stroke. The -R core seating die (CS-1-R) is nearly the same design as the core swage, except the bore is larger and the external punch either makes a lead nose and fits the die bore, or makes an open tip and fits inside a certain wall thickness of jacket. All of the -R dies are 5/8-24 thread and have a 5/8-inch body, which screws into a black 7/8-14 thread adapter. This adapter is bored nearly through the other end, but the hole stops short of going all the way. A quarter-inch diameter hole does go through, and takes the ejector rod which is tapped firmly to eject the component. The internal punch is captive within the adapter, and can be changed by unscrewing the die from the holder. The -R point forming die (PF-1-R) uses a music wire coil spring to keep the ejection pin pushed to the top position within the adapter body. Ejection pins are typically .081 inch diameter for these dies, which are made in .224 and .243 caliber in 6-S ogive shape. Other calibers, ejection pin sizes, and ogive shapes are custom items (which usually are best made for a swaging press in -S or -H type). The -R lead tip forming die (LT-1-R) is nearly identical to the CS-1-R core seating die, except that the bullet goes into it facing upward, tip toward the die. The internal punch has a cavity shaped like the bullet tip, and reshapes the lead to make a sharper end than can be made with the .081-inch diameter ejection pin in the point forming die. Those four dies can be combined to make two-die sets (CS-1-R and PF-1-R) as with our standard .224 and .243 bullet making kits, a three-die set by adding the CSW-1-R core swage, or a four-die set by adding the LT-1-R to make nice sharp lead tips. The CSW-1-R and CS-1-R can be used as a pair, also, to make semi-wadcutter bullets. However, the PRO-1-R die can do the same thing by using a weight-adjusting punch (with a hole through it) to set the exact core weight and then changing to a nose punch to create the actual nose shape. General instruction for swaging in a reloading pressSome folk have complained that there was no simple, 1-2-3 instruction for swaging bullets, and they didn't want to read a lot of details about how to do it right. For those who might feel this way, here are the simple 1-2-3 instructions for making a lead rifle or pistol SWC type bullet of any nose or base shape using the PRO-1-R or CS-1-R die:
1. Cut or cast cores to desired weight, and lubricate them with Corbin Swage Lube. A little lube on your fingertips will be all you need. 2. Put the die in the press head and the bottom punch in the press ram, and then put a lubricated lead core in the die. 3. Adjust the die so you form a finished bullet at the end of the stroke, with the press ram all the way up just as the bullet forms completely. Make as many bullets as you need once you have the die adjusted. | |||
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And for jacketed bullets made in a core seater and point forming die (ogival shape, no shoulder), the most basic operation skips the core swage die and uses a cast or cut core directly in the jacket: 1. Cast or cut the core to the desired weight (bullet weight minus the jacket weight) and put the clean, unlubricated core into the jacket. Lubricate the jacket lightly with Corbin Swage Lube, and put it into the core seating die. 2. Use a core seating punch that snugly seals the jacket and press gently to expand the lead inside the jacket, until the jacket expands and contacts the die walls evenly. The jacket and core must stay up in the die when you lower the press ram. Eject the seated core and jacket by tapping on the knockout rod placed in the top of the die. 3. Remove the core seating die after you have seated a quantity of cores in the jackets, and replace it with the point forming die (which has a spring-loaded internal punch you can feel by pushing the knockout rod by hand). 4. With the point forming die high in the press threads, place the open jacket and core mouth upward, open end facing the die, into the die cavity. Use the largest diameter punch in the set, which just fits into the die, to push on the closed base of the jacket. Raise the ram all the way or until you encounter resistance. 5. If you do not encounter any resistance with the ram at the top of its stroke, turn the die to lower it until you cannot turn it any further by hand. If you do feel some resistance, lower the ram and inspect the bullet to see if the ogive has formed. If not, or if you felt no resistance, lower the ram slightly and give the die another 1/4 turn lower. Raise the ram, then lower it and knock out the bullet. 6. Examine the bullet, and if the tip is not yet closed down to the size of the ejection pin (.081 inches in most dies), continue to lower the die in small increments and re-form the tip until it reaches this point. If you go too far, the bullet will acquire a little pipe on the tip from extruding the jacket up the ejection pin hole. Just short of this, you have finished!
Detailed swaging instructions for a reloading pressFor those of you who would like to know both why and how to do it right, here are the details and the reasons behind them:
Remove any shell holder from your reloading press, and clean out the slotted ram with a swab to remove any accumulated primer residue and shavings. These can prevent alignment of the swaging punch and die. Snap the reloading press punch into the ram (like a shell holder). Don't try to use a shell holder in addition! Screw the die into the top of the press just a few turns. Don't try to set up as you would a reloading press die (against the end of the ram). Just barely get it started. We want to use the top of the stroke for a positive stopping point, and adjust the die up and down to get the right pressure and nose shape, so we have to start with the die too high, and slowly bring it down while making our initial adjustment. | |||
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Cut the lead wire, or cast scrap lead cores to the right weight. If you are using a core swage die, add about five grains to the desired final weight. For jacketed bullets, put the jacket in the scale pan, cut a piece of lead wire and adjust the length so that the total weight (jacket and core) are a few grains more than you desire for the finished bullet. Without a core swage die, the total of bullet jacket and core is the finished weight. Open a bottle of Corbin Swage Lube. Put a tiny bit of lube on your finger tip, and when you pick up the lead core, give the core a turn between your thumb and finger tip. That's all the lubricant you need. (If you are using a core swage die, that is.) Put the core into the mouth of the core swage die, then carefully raise the ram of the press until you can remove your finger and let the punch hold the core. Gently raise the ram all the way. If the punch is stopped before you get to the end of the press stroke, raise the die slightly. If you are not using a core swage die, then put a clean, unlubricated core into the jacket, lube the OD of the jacket, and put it into the core seat die. Follow exactly the same adjustment procedure. With the ram of the press as high as it can go, lower the die (screw it down, toward the ram) until you can't turn it by hand any further. You've just pushed the lead core up against the end of the internal and external punches. It is important to understand why you are doing this initial adjustment: it is to use the end of the press stroke, where you have maximum power, and to provide a consistent point of reference so all your cores will be made exactly the same. If you stop short of the press top, then the distance between the top and bottom punches is arbitrary and will change from stroke to stroke. This leaves different amounts of volume within the die on each stroke, so naturally you don't get the same bullet weight in a core swage, or amount of closure in a point form die. Lower the handle of the press very slightly, and turn the die about half a turn closer to the ram, then raise the ram again. When you feel a slight resistance on the handle, lower the ram all the way and inspect the core (or seated core, or finished bullet, depending on the die you are using). To eject the bullet, put the knockout rod into the top of the die and tap it firmly with a plastic mallet. When the lead forms completely (square ends, sharp edges, full diameter of the die with parallel sides), you have found the correct adjustment. If, during this process, you feel that the pressure is too great (too much force on the handle—you should not feel more than about what it takes to seat a bullet or expand the mouth of a cartridge case), stop and inspect the lead. Perhaps it is much harder than you thought. Only pure, soft lead is really suitable for reloading press swage dies. If lead spurts around the punch, you are using too small a punch diameter for the operation. Lock down the locking rings on the die, and proceed to swage all the cores you wish. Use care to insure that the punch tip goes into the die and doesn't strike the edge. (Make sure it doesn't pinch your finger, either: that hurts!) When swaging lead cores in a reloading press, it is important that each stroke is exactly the same distance, so you leave the same volume or spacing between the top and bottom punches inside the die. The extra lead will be extruded through a hole in the bottom punch. | |||
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With a core swage die, or a "bleed-off" punch used in a PRO-1-R die, you will note that there is a little "antenna" or bleed-off of lead on the end of each lead cylinder. Snip these off with a pocked knife or nail clippers. If you don't get this bleed-off, your cores may vary in weight. A core swage can only remove extra lead—it can't add more. That means your cores must be cut, or cast, heavy enough so that all the variation is smaller than the amount of extra lead you left to swage off. Clean the lubricant from the cores, if you intend to put them into jackets next. For lead bullets, you don't need to clean them yet. To remove the lubricant, you can slosh the bullets around in a can of organic solvent such as acetone, or Corbin's Cleaning Solvent. Or you can wash them in hot water with a little detergent added. Either way, roll them on adsorbent cloth or paper towel to dry them. To make a Keith semi-wadcutter (a variety of truncated conical bullet), you would select the CS-1-R or the PRO-1-R die and a nose punch of the desired shape. If you want a hollow base, cup base, flat base, or a Base-Guard base, select the punch having the face that is machined to transfer that shape to the bullet. The punch trapped inside the die body is the internal punch. The punch that snaps into the ram slot is the external punch. Both can be changed, to change the base or nose shape. Place the cleaned cores into jackets. Just set them in the jackets. You want to avoid getting any lubricant inside, since it will just keep the core from pressing firmly against the jacket wall. Then, put a drop of lube on your fingertip, and pick up the jacket (with core inside). Put the jacket into the die, so that the lead faces the nose forming punch. Please note that the lead core must drop into the jacket easily without stopping against the die wall (needs to fit to the bottom). If you try to mash the lead into the jacket when it doesn't fit correctly, you'll trap air below it, and it could pop the core out again later! Not all diameters of cores for a given caliber will fit into all the jackets that could be available for that caliber: jackets can have different wall thicknesses, and require different core sizes. Swage as described previously for making the cores. One difference: if you are using a jacket and an external punch that forms a semi-wadcutter or a lead tip bullet, the length (and thus the weight) of the lead core must be such that the lead will be at least as long as the jacket after the core is fully seated. If you try to use too light a core for the jacket length, and a punch that requires lead to fill its cavity, the punch will push against the edge of the jacket and wrinkle the jacket. You could damage the punch. Please note also that you only need as much pressure as it takes to expand the jacket to fully touch the die ID. Using more pressure than it takes to expand the jacket overstresses the die and could lead to breakage of the die. Just use the minimum effort required to get the jacketed bullet to fill out properly and become the proper diameter. This should require very little effort in smaller calibers, with increasing effort as you get above .308 and into the large pistol or paper-patched rifle calibers. Proceed carefully so you do not break the die from excess pressure. | |||
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Lead cores expand and become shorter as you seat them: you need sufficient length of lead so that there will be material to fill the cavity in the external punch tip. If you are using a hollow point punch, use it first to extrude lead forward, and then shape the lead with the second punch. If the hollow point is uneven, try flattening the lead core first with a flat punch, then use the hollow point punch, and finally use the Keith or other semi-wadcutter punch. If you are making a BG (Base-Guard) style of base, you might wish to pre-form the bullet without the copper disk first, then put the disk into the die with the peak of the cone-shaped disk facing the lead. Push the bullet back into the die against the BG disk, so that the lead flows through the hole in the disk and forms a rivet head in the small depression in the center of the base punch. You can try forming the BG disk onto the bullet in one stroke, and it will probably work if the end of your lead core is flat enough. Typical cut cores have an angle, which may make it harder to get a good, straight alignment of the BG disk. Pre-shaping them solves that problem nicely.
You may be done at this point, if you are making semi-wadcutter style bullets (which includes paper-patched rifle bullets or any other type having the SWC shoulder). If so, congratulations! Wipe the lube off the bullets and you are ready to load them. If not, it means you have one or two more steps to perform to make a smooth ogive bullet or to form one with a small lead tip. To form a smooth ogive, lead tip bullet, you need to make a seated core with exposed lead beyond the jacket. If you want a smooth ogive, open tip bullet, then you need to use a punch that fits inside the jacket, rather than just inside the die. The core is made shorter than the jacket. We call this the "open tip" style. A "hollow point" is something else: you make a HP bullet by pushing a punch with a conical projection into the lead core, so that a hole is pressed in the lead. The core can be down inside the jacket at the time (making an open tip hollow point) or it can extend beyond the jacket (making a lead tip hollow point). Press the core down so it fills up the jacket, then stop pressing. Remove the core seating die, and replace it with the point form die (PF1R). With the point form die in place, and a full-diameter base punch in the press ram (which just slides into the point form die by hand with very little tolerance), put a small amount of lubricant on your fingertip and roll the seated core and jacket between your thumb and forefinger. Put the seated core and jacket into the point forming die, so that the lead faces up (toward the die). Gently push the punch in behind the bullet and adjust the die position so that you feel only a light resistance when swaging at the end of the stroke. Eject and examine the bullet. If there is a pipe or extension on the end of the bullet, it means that you have the die just a bit too low. Turn it counterclockwise very slightly. If the bullet won't eject or has a large, rough and unfinished looking tip, it means you have not pushed it far enough into the die. There is a position where you will get maximum tip closure before the lead flows up the ejection pin hole. You can find it by trial and error. (Hint: save a good bullet to use as a setting gauge next time. Put the bullet in the die, raise the punch and ram, and screw the die down until it stops.) | |||
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To make a smooth flat tip on your bullet, just turn it over, push it backward into the die, and gently bump it on the nose with the base punch. It doesn't take much pressure. You can make any size of flat point this way. If you are making a handgun bullet, you have finished. Wipe off the lube, and load it. If you are making a lead tip rifle bullet, you may need to go to one more die: the lead tip forming die. To finish a lead tip rifle bullet, remove the point forming die and install the lead tip forming die. You'll notice that the lead tip is deformed and mushroomed by the force of ejection. The secret of making a good lead tip bullet is to leave plenty of lead: your core needs to be longer than the jacket and you need to make sure you don't close the jacket down so small that it leaves no room for a strong stem of lead joining the tip with the main body of the core. The wall thickness of the jacket, at the tip of the bullet, can use up a considerable distance across the total tip distance. The jacket walls need to be far apart at the tip, so that a strong stem of lead comes up between them and holds the tip in place. Push the bullet up into the lead tip forming die and let the internal punch reshape and shear off any extra lead extruded from the tip. If you press very hard, a ring will be impressed in the ogive section. Find that delicate point where you just shave off the extra lead and leave no mark on the jacket. It works very nicely. Paper-Patched Lead BulletsIf you want to make a paper-patched bullet, just install the PRO-1-R Pro-swage, cut or cast some lead cores of the right weight, and swage them using the gentle, increasing pressure method until you get the right shape. Typically, if you had 0.0025 inch thick paper, you'd want the bullet to fill the grooves at .458 inch diameter with two complete wraps. That means you'd take .458 and subtract four times .0025 (two wraps, but doubled because it is on both sides of the bullet) and make the bullet .448- inches in diameter (before patching). The only difference between a paper-patched bullet swage die, and one for making a bullet that will be dip-lubed or grooved and lubricated, is the diameter of the swage. Most paper-patched bullets also use a cup base shape, so you can tuck the twisted end of the paper patch into it, but that is entirely up to you. The formula for determining die size (D) for any caliber of paper-patched bullet when you know the barrel's diameter across the grooves (G) and the thickness of the paper (T) is: D = G - 4T If you know the bore size (B) and depth of rifling (R), and paper thickness (T) that you have available, then you can calculate bullet size (and die diameter D) this way: D = B + 2R -4T You can purchase one swage die and a bullet grooving tool (similar to a cannelure tool but with wider grooves for lead bullets) for lubricated full size bullets, and get a bullet reducing die for making paper patched bullets out of these, but the cost is just about the same as getting a second die. Also, you can try something interesting with two dies of different diameter that are made for paper | |||
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patching and for shooting directly as swaged: you can wrap the smaller bullet with teflon pipe tape and swage it upward in size in the second die! This gives you the proper size bullet with a teflon jacket swaged into place. Of course, if you shoot in a match you'll need to check the rules first. You can try this with paper, too, by using a slightly thinner paper than the smaller die was originally designed to use, so the paper-patched bullet will fit easily into the second die and pressure will shorten and expand the bullet, rather than scraping the paper off as you try to insert it. You actually have the ability to make several kinds of bullets with two diameters of the same shape bullet, rather than just the two styles. Swaging lends itself to experimentation and combinations that create new ideas, so long as you remember that anything going into a swage die should be smaller than the die bore. Never swage down, just like you never draw up. Always swage larger, with the odd exception of the dual diameter sizer die which combines drawing and swaging in one tool (and has its limits, as you can read in the section that discusses this exception to the first rule of swaging). Full-jacket Open Base (military style) BulletsJust put the bullet jacket in the point forming die, with the open end facing the die mouth. Push a piece of lead core into the jacket with a punch that fits inside the jacket mouth. The seated core should be just below the jacket mouth, perhaps one eighth or less of an inch. Don't try to make too sharp a point, because the jacket will just break through if you do. Eject the bullet. You'll have formed the ogive on the normal base end of the jacket. (Having a flat ended jacket makes no difference: the pressure will expand and reshape the end just as if the copper were a balloon skin.) But to finish this bullet, you must do something else: you must roll the open end of the jacket over the core. If you leave the base open, when the bullet is fired the muzzle gas pressure will peel the jacket away from the core and the bullet will be very inaccurate. It might even cut ragged asterisks in the target instead of round holes, from having the jacket expanded so much that it splits at the base. To get the muzzle gas to help you keep the jacket folded tightly on the bullet, reverse the bullet and put the open end into the point forming die. Gently push on the bullet nose with your punch. The curved die wall will move the edges of the open jacket slightly inward. Eject the bullet again, turn it over once more, and push it back into the die. Now, you have an angle applied to the open base. The pressure of pushing the bullet back into the die nose first, one final time while using a flat punch will flatten this angle, folding the jacket over the core. Gas pressure on the base of the bullet will help hold it shut, not tear it apart. For this to work, the empty projecting jacket needs to be just the right length. Too long, and you get a buckle or wrinkled line around the base. Too short, and the lead spurts out and smears over the base. Just right, and you get perfect military style bases. This means you either have to adjust the jacket length or adjust the bullet weight slightly to get the right ratio of core to jacket. The jacket length can be adjusted with an ET-1-R jacket trim die. | |||
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Let me summarize this quickly: 1) seat the core in the jacket using the point forming die, to form a full metal tip and open base, 2) turn the bullet over and push it backward into the point forming die with a flat base punch to gently roll the open end into a slight boattail shape, 3) turn the bullet over again and push it nose first into the point form die with a flat punch to securely flatten the jacket edge over the core. If you want to do this more precisely, we can provide a "FMJ Base-Turning" punch that has a concave face, in order to help make a better fold prior to using the final flat punch. This inserts a step between 2 and 3, where you apply this sharp fold point with the FMJ punch. Changing the Nose and Base ShapeWith semi-wadcutter and wadcutter styles, the nose shape is controlled by the punch you select. With smooth ogive bullets (those without a step between the shank and the nose), the ogive is controlled by the particular point forming die that finishes the bullet. To change nose shapes with a bullet that uses a point forming die, you need a different shape of point forming die. That is the PF-1-R. If the bullet is finished in an PRO-1-R or a CS-1-R die, then all you need is a different nose punch. It is important to understand this, because it makes a big difference in planning and ordering. Point forming dies cost about six times more than a punch, so if you can use a bullet with a little shoulder and a lead nose instead of having a smooth curve without a shoulder between ogive and shank, you'll save money on tooling. If you need the smooth ogive shape, then the matched pair (core seater and point former) is the only way to do it. Spare punches can be purchased in standard shapes of flat base, dish base, cup base, hollow base, or Base-Guard base. Nose punches can be purchased in conical, Keith (semi-wadcutter, truncated conical), 3/4-E pistol round nose, target wadcutter, button nose wadcutter, hollow point (a universal HP punch that works in conjunction with any other punch), open tip, or 1-E rifle round nose. Other custom shapes can be specified (with dimensioned sketch or sample) at extra cost for the additional shop time and tooling. Open tip core seating punches must be made the correct diameter to fit into whatever jacket you plan to use. If you order a set for use with a rimfire jacket, and then try to use a commercial jacket, you'll find the core seating punch is too large and will dig into the commercial jacket wall. If you order a core seating punch to fit any specific jacket, either specify one of ours to fit, or send us three or four samples so we can match the average size to the punch. This is very important. If you try to use the wrong punch diameter, lead can spurt out around the punch, the pressure won't develop to expand the jacket, and you can get undersized or tapered bullets as a result. | |||
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Boattail and Partitioned DesignsThose are best done in swaging presses, not in a reloading press. But you can simulate a boattail by pushing a bullet backward into a point forming die, thus applying a slope or angle to the base. Then form the nose in the same die by reversing the bullet. Because it takes less force to shape the open end of the jacket than to change the base shape (on most jacket, the base is thicker), the same pressure will create a nose without materially removing the base angle. This doesn't work for all bullet styles and calibers, but you can try it. To make a good partition style bullet, use another jacket small enough to fit inside, and short enough to fill just a little more than half the larger jacket's length. Or, in the .224 and .243 calibers, use fired primers as heavy walls between two short pieces of lead core! A .243 jacket makes a good partition in a .30 caliber jacket, and a short .30 jacket fits inside a .358 or .38 jacket. You can seat a core in the smaller jacket first, with lead exposed, then put the lead end down, into the larger jacket, and seat the assembly like a core to expand it in the larger jacket. Top that with a short piece of lead core, and finish as usual. Fired .22 Case JacketsMaking bullet jackets for .224 and .243 caliber bullets from the spent cases of fired .22 ammunition is, even after all these years, a very popular way to make free bullets that perform as well, sometimes better, than the ones you buy. Corbin builds the RFJM-22R Rimfire Jacket-maker to gently unfold and redraw the rimfire case, making it into a jacket that looks for all the world as if it were intended to be that way. Bullets made with a rimfire case for a jacket have much more explosive expansion than those made with conventional jackets. Friction is lower in the bore, so your rifled barrels last longer. Fouling is less, partly because of the higher zinc content of cartridge brass and partly because the thin jackets need to be loaded to lower velocity to avoid coming apart in the air. The performance of fired .22 cases used for jacketed bullets is outstanding. The price is right (free). About 1976, Wolfe Publishing's "Handloader" magazine published an article wherein Rick Jamison (currently with "Shooting Times" magazine) made some rimfire jacket bullets and shot them from a benchrest rifle. The groups obtained were in the 0.200 inch category, and the same gun and loads used with Sierra match bullets got slightly larger groups, and slightly smaller groups with certain of the custom swaged benchrest bullets using commercial jackets. The point is, rimfire jacket bullets are at least as accurate as the ones you buy, produce less fouling, are easier on your gun's bore, and cost you nothing. Their only drawback is the need to load them to lower velocity because they are very thin and explosive. At 3200 feet per second, a rimfire jacketed .224 or .243 bullet performs more violently than a conventional bullet driven to over 4,000 feet per second! Your varmint hunting expeditions are safer with them, because there is | |||
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almost never a ricochet: once these bullets touch the ground, they disintegrate. (See the chapter on jacket drawing for instructions on the use of the RFJM-22 and RFJM-6M dies.) Briefly, rimfire jackets are made by lubricating and pushing cleaned .22 Long Rifle, Long, or Short cases through the proper die, using a punch which fits inside the jacket. The point of adjustment is somewhat critical: too high in the press and you can't finish pushing the jacket through, so the next one may jam into it, and too low in the press requires way too much effort, even to the point where you could pry the press off your bench. (Rick Jamison actually broke his reloading bench, so if you did not understand the importance of correct die adjustment, you are in good company!) When you find that exact position where the force required is leveraged by the press and quite manageable by the operator, and the jacket goes all the way past the tightest point in the die, you can process hundreds of jackets per hour as fast as you can push them through. After drawing, they need to be annealed or softened, so that the tips won't fold over when you form the ogive. If you use enough lead to support the ogive fully and do not bring it to a small point, you can skip this. But if the bullet you want to make gets a triangular flap of metal folded over at the nose, then you need to anneal the rest of the jackets. This can be done by heating them briefly with a propane torch, just long enough to bring them to a slight red glow in a dimly lighted room. No quenching, no lengthy heating is required. A few seconds will do it. Corbin offers a heat treatment block kit, consisting of two high temperature ceramic blocks and a drill template that you can tape over one of them. Use a regular wood "spade" bit to drill a series of holes matching the template, and you have an efficient way to heat treat jackets or bond cores. One block holds the jackets and reflects the heat evenly around them, and the other block is propped up behind the first one to act as a backstop and further reflect heat from the back side. I highly recommend this procedure, because it is cheap and easy, and very fast. Open Tip, Lead Tip, and Hollow PointFor open tipped bullets, you need to use a punch that slips inside the jacket (and a core length short enough to allow this). For lead tipped bullets, you need to use a punch that fills the die bore, not the jacket I.D., or else seat the lead core very close to the end of the jacket. When the ogive is formed on the bullet, the lead will move forward and extrude from the open end if there is enough lead. A lead tipped bullet expands more quickly than an open tipped bullet, since the jacket is left with a larger opening. The jacket opening controls the expansion far more effectively than the amount of lead exposed. A hollow point, on the other hand, may expand faster or not, depending on what it hits and whether the initial contact plugs up the cavity and turns the bullet into an effective solid nose. To make a hollow point bullet, you would seat the core using a punch that had a conical projection on the tip. This forces a hole into the lead, perfectly centered. This punch can fit either the die bore (for making lead tip hollow points) | |||
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or it can fit the jacket I.D. (for making open tip hollow points). You can see why it is important that you use the terms "open tip" and "hollow point" correctly, since they require different equipment. You can have an O.T.H.P. or a L.T.H.P. but you cannot, by definition, have a L.T.O.P. or an O.P.L.T. (same thing stated another way). This is because O.P. means open point, lead core shorter than the jacket. L.T. means lead tip, lead core longer than the jacket. It can't be both at the same time. But it can be shorter than the jacket with a hole poked into it, just as it can be longer than the jacket with a hole poked into it. The hole is the H.P. It's not that hard to learn and it can save you mis-shipped items and delays while the terms are restated correctly the second time around! The problem is that many other bullet makers tend to mix up the terms. They do not need to be clear about it, since they are not selling you any tooling to make your own bullets. If Speer calls an open tip bullet a hollow point, it hardly makes any difference to you or to them. We have to be more precise. | |||
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10. Bullet Swaging PressesCorbin builds several models of bullet swaging presses. The presses each have a range of capabilities, and dies of a size that match those capabilities. Some of our older literature refers to the Silver Press (CSP-3), or the Mity Mite press. These are discontinued, horizontal ram cast-frame models, which accepted a small diameter of die called the type -M. The -M dies used 5/8-24 threads, same as our -S dies, but had a body of 3/4-inch instead of 1-inch. The -M dies can be made on special order to fit older Corbin presses. More recent literature and published articles and advertising, especially during from about 1995 to 2002, referred to the Series II press. This had the catalog number of CSP-1, and was replaced by our current S-Press, which looks similar. The Series II was built entirely of steel, and except for the first version, had needle bearings in the links. It used a stop pin and ejection system similar to the Silver Press, which in turn required a slotted punch head on the ejection punches. The stop pin was supported with a hardened bushing pressed into the front of the frame, but did not extend through the ram. The ram was slotted only on one side. Today, Corbin builds two hand-powered presses, the S-Press (CSP-1) and the Mega-Mite (CSP-2). The S-Press uses type -S dies, which have the 1-inch main body with a 5/8-24 threaded shank, providing a wide shoulder to adsorb axial force against the top of the ram (instead of passing the stress through the threads). The S-Press also uses a ram slotted through both sides, and a long stop pin that passes completely through the ram. The punch heads for -S type ejection punches have a hole through them, rather than a slot. They are also larger in diameter than earlier -S or -M internal punch heads. Older -M and -S dies can still be used in the S-Press, however, by using a short stop pin with it. Current production internal punches have a punch head too large to fit into the older presses, however. This is easily fixed by sending in your older press for an upgrade, which will bring it up to current standards for less than half the price of a new press. The Mega-Mite uses type -H dies, same as our larger power presses. The -H dies have threads of 1-12 (1 inch diameter, 12 turns per inch) on their shank, and have a 1.50-inch diameter main body. It is suggested when you want to make bullets larger, longer, or from harder material than can be reasonably swaged in the S-Press, or when you want to move toward a power press but would like to start with less investment (the dies interchange with the larger power presses). Corbin builds three models of power presses, which operate from either 115 volt 60 Hz single phase power (standard household supply in the USA), or from 220-240 volt 50 or 60 Hz single phase power (optional, for export to other countries). The three power presses are the Hydro-Mite (CSP-1H), which uses -S dies and is bench mounted with separate controls and power unit; Hydro-Junior, which is a self-contained cabinet model press using -H dies; and the Hydro-Press, a self-contained cabinet model with automatic timing, stroke control, and interfaces for automatic feed of copper strip for jacket making operations. | |||
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Advantages of a swaging press
In addition to the press itself, the Corbin -S dies give you further reason to use this advanced swaging system. Since Corbin pioneered the semi-custom manufacturing method for swaging, where standard presses and die dimensions within broad families allow us to make large "blank parts" runs, and then finish the cavities and punches as your orders are entered, instead of "reinventing" each particular set of tooling from scratch with every new design of bullet, it has become practical to manufacture custom calibers, shapes and designs of bullet swages without paying huge prices. | |||
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This is practical with all Corbin presses, because we can control the tolerances and dimensions of the entire swaging system and are not at the mercy of dozens of different press manufacturers, each with their own ideas of tolerances and dimensions for ram slots, press heads, ram travel, ram diameters and leverage systems. Certain standard lengths of dies and punches handle all the various calibers from .123 to .998 diameter in all practical lengths of bullets. Thus, we can manufacture huge "runs" of die blanks in the appropriate lengths, matched to the standard punch blank lengths, and achieve great cost savings over making all these one at a time. When your order for a special benchrest .243 with a 14-caliber secant ogive and an 8 degree boattail comes in, we know right away that all we have to do is reach into the bin of 2 inch long die blanks and pull out three of these, knurled and threaded, center-drilled and ready for the die cavities. We know for certain that we can use internal punch blanks manufactured while the machines were set up for a week's total production of nothing but these blanks. They'll fit perfectly, once we diamond lap, heat treat and hand fit them to their die cavities. In other words, you save hundreds, perhaps thousands of dollars in some cases, and get the same quality of die, compared to fiddling with someone else's press and coming up with a unique set of dies just to fit it, or compared to making low volume, single-unit custom parts from scratch on every order (as most of the bullet swage die firms have done in the past). One final reason to get a Corbin Press instead of trying to buy custom reloading press dies is that the price of the press and a complete set of dies to fit it, is usually less than half the cost of any comparable quality alternative. Those who make "benchrest" swage dies generally charge from $1500 to $3500 for a set of just the dies. They probably fit your reloading press, since few die-makers today build actual bullet swaging presses. But look at how much money you'd save by getting a press designed for precision bullet making, instead of buying the efforts of a die-maker who is attempting to design around the limitations of a reloading press! S-Press, CSP-1This is the most popular press today, because it not only accepts the original type -M dies, but also uses 1 inch diameter type -S die (same threaded shank size, 5/8-24 tpi) in the ram. The S-Press is a vertical design, with the floating punch holder in the press head, which uses the same 7/8-14 thread as conventional reloading dies. An adapter converts the ram to hold regular button shell holders, and arbor press anvil inserts are available for the punch holder and the ram, for use with benchrest reloading dies. The S-Press looks like a Roman numeral II from the front. It is machined from steel, not cast iron, so it is smaller and lighter than iron presses, which have less tensile strength and half the power. The ram linkage can be quickly set for 4-inch or 2-inch stroke (reloading, or swaging). A set of four needle bearings in the links provides smooth operation. Bearings also surround the ram. | |||
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Bullets from .123 to .458 caliber, with a length limit of 1.3 inches, are well within the range of most small arms calibers, and are also within the capability of the S-Press. The advantage of the S-Press over conventional reloading presses is the greater strength (up to 130,000 PSI versus 35,000 PSI), higher leverage due to the full 180 degree arc of the handle travel and dual stroke length, more sophisticated engineering (all moving contact points use bearings, including the ram, which is surrounded by two inch-long bearings mounted in a precision honed cylinder), and capability to do reloading. The CSP-1 press comes with a FPH-1-S floating punch holder and a reloading adapter (to hold standard RCBS shell holders in the ram, extend the ram height, and provide a port for spent primers to drop into the primer catcher tray, also provided). A stop pin, mounted in the front of the press, pulls out so you can use a long reloading stroke, and pushes back in so you can use it to stop the downward movement of swaging punches and cause automatic bullet ejection on the down stroke. The long stroke is set by removing a retainer pin (which looks a little like a hand grenade pin) from the link, pushing the steel pin out of the ram and toggle, and moving the ram to a second set of holes in the toggle, then pushing the pin back in and replacing the retainer pin. This is easily done by hand: just wiggle the toggle and ram a bit as you push out or push in the pivot pin to help get it lined up in the ram bearing. The CSP-1 press would be the right choice if you plan to make bullets from .123 to .458 diameter, in lengths of 1.3 or less inches, with a core material that is no harder than Bhn 12 (and this should become less as the point becomes sharper and the diameter becomes larger, so that a spitzer .458 would probably need to be no harder than Bhn 6 to Bhn 8) in the type -S dies. With harder alloys, the guiding factor is your tolerance for being careful, and the odds of breaking the die doing experiments. If you might use a little wheelweight alloy from time to time, might get in a hurry sometimes and throw the handle pretty quickly when swaging, or want to play around with some techniques that no one may have tried yet, then the type -H dies and the larger CSP-2 press is a much better choice. If you want a caliber over .458, or a length of bullet over 1.3 inches, or a hardness of material over Bhn 12 (such as a steady diet of wheel weight alloys or linotype) then you want type -H dies and the larger presses that use them. All the wishful thinking and rationalizations in the world won't make you any happier later, when you break the die, no matter how much work it was to get the person on the phone to agree with you, eventually, that maybe, yes, you might be able to get away with the less expensive equipment for jobs it wasn't designed to do. You might also bag an elephant with a .22 long rifle, but I'm not going to stand in that elephant's path while you try it. Sometimes a person will spend a hour on the phone trying to wheedle an admission that something might work, so they can save a few dollars and buy an inappropriate tool based on this "advice", and then later on, when it finally breaks from continued abuse, they can whine about it and try to get another one free (which will also break eventually). | |||
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Please! Give me a break, not the die. The -S dies do a great job for the materials and dimensions for which they were designed, and that is what they are warantied to do. Anything else that works is just pushing the envelope, and you might get away with it, but if it breaks, you still own both parts. The larger -H dies and presses are made because there are situations where they are required for reliable operation, not just to make unnecessary larger sales. I'll be the first one to tell you that you don't need something larger, if the smaller one will be perfectly fine. Usually, getting a larger than necessary hand press isn't a good idea because you work harder than necessary operating it. A power press is a delight to use even if you don't really need it for the job, on the other hand. Mounting the CSP-1 PressThe S-Press mounts directly to your loading bench, or you can purchase the optional CSP-B Bench Stand. This sturdy steel stand puts the press about a foot higher than your bench top, so you can look directly into the area where the external punch enters the die, and so you gain some extra leverage on the handle. The Bench Stand has a shelf to hold spare parts and dies and a thick steel reinforcing plate that mounts under the top section. The press is held slightly forward, over the bench edge, to keep the handle from striking the front of your bench. Using the Bench Stand gives you room both under the stand and on the shelf, so you wind up having more storage room than before, instead of decreasing your bench space. But the main reason I like it is that most reloading benches are the right height for reloading, where you want to look down into the case during operations, and with swaging it is better to look straight at the die during the swaging stroke, so you can watch the punch and die come together. Corbin also offers the CSP-S Floor Stand, which is a heavy steel assembly using a vertical post like a drill press to support an inch-thick mounting plate so you can view the operation from a standing or shop stool seated position. The same floor stand fits both the CSP-1 and CSP-2 presses. We drill and tap two sets of bolt hole patterns, just in case you want to use the other press. The Floor Stand needs no mounting: it has a deck on which you stand, and your own weight is sufficient to stabilize the operation. This makes it ideal for rented spaces where you cannot put holes in the floor or build in a sturdy bench. It also makes the press somewhat portable, since you can slide the bench stand around to get it out of the way when you are not using the press. The floor stand is heavy enough so it has to be shipped by truck. If you order it with the other items, it usually doesn't cost any more to ship them all in the same carton. Changing the Stroke LengthThe CSP-1 press has two stroke "modes" or settings. The short stroke is two inches of ram travel, and the long stroke is four inches. For bullet swaging, where the die screws into the press ram, you want to use the short stroke and the stop pin should be in place in the front of the press. But for jacket or bullet drawing, and for reloading operations where the die goes into the press head (top), you | |||
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want to remove the stop pin and use the long stroke. The ram position at the end of the stroke is designed to match the reloading adapter height and the use of shell holders or drawing punch base lengths, so that you can get the proper position of the die at the end of the press stroke. When changing the stroke length, I like to position the ram so that I can insert the stop pin before I remove the pin that holds the ram to the toggle. Nothing keeps the ram in the press, once you have removed the ram to toggle pin, other than the stop pin, so you want to keep on hand on it to prevent it from sliding out of the press and falling on the floor (or your foot!) or else make sure the stop pin holds it in place until the ram to toggle pin is back in place. Don't forget to remove the stop pin in the long stroke mode, though. Otherwise you will wonder why you can only move the handle through part of its travel! The CSP-1 has a special feature not present on most reloading presses, and that is the offset toggle arms that straddle the ram, allowing for a full 180-degree rotation of the toggle. This can add another 20 to 25% effective leverage to the press, even in the same stroke mode as a conventional reloading press. Many popular reloading presses have a 135-degree handle arc, which limits the amount of leverage (a ratio of distance times the degrees of travel for the handle, divided by the distance moved by the ram). By increasing the "input" travel for the same amount of "output" travel, ram tonnage is increased for any specific integral of travel, since the press leverage is designed around a log-function power curve. For instance, for a 1 inch arc movement of the handle at a given point in ram travel, you might get a 1,000 times multiplier of force, whereas the next 1 inch movement of handle would get a 10,000 times multiplier of force, approaching near infinite force as the ram movement approaches zero for the same 1-inch arc travel at the end of the stroke. But I don't want to put anyone to sleep just yet, so let's skip the math. Mega-Mite Press, CSP-2 ModelThe Mega-Mite is a huge version of the CSP-1 S-Press, weighing over 75 pounds and having a dual stroke of 3 and 6 inches. The press also uses needle bearing links—much larger ones than the CSP-1 model—and a huge hardened steel ram guided at the top by a bearing-aligned steel plate which runs up and down on two massive hardened and ground guide rods. The Mega-Mite uses type -H dies, and can be used with the reloading adapter kit. The press head is removable, as it is in the S-Press, but uses a 1.5 inch 12 tpi threaded plate for the FPH-1-H punch holder. The ram accepts 1 inch 12 tpi threaded dies or punches, rather than the 5/8-24 tpi of the S-Press (-S) dies. The standard type -H die is made with a 1.5 inch outside diameter. Custom -HC dies can be ordered with 2 inch, 2.5 inch, or even 3 inch diameters where appropriate for the pressure. The same dies which fit the powerful Corbin Hydro-Press also fit into the Mega-Mite press. This does not mean every die set of type -H will work in the Mega-Mite, because there are some calibers and materials that require much greater pressure to form. For example, the Mega-Mite press has no problem accepting any | |||
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lead hardness, but you cannot exert enough force to swage finned 12-gauge shotgun slugs (although this can easily be done in the Corbin Hydro-Press using the same dies). Also, the stroke length and power cycle affect some designs of bullets: you can swage a soft lead .600 Nitro bullet in the Mega-Mite, but you can not make the same caliber with a spitzer nose, or with a hard lead core, even though the press and dies can make long spitzer noses in smaller calibers, and even though the dies can handle harder lead without breaking. The pressure in a hand press is primarily generated at the end of the stroke, so if you have bullets that form the nose in the last half inch of travel, then you probably have plenty of force during the last half inch to do it. If you made a .500 A.E. pistol bullet, the blunt nose and short length means you can use the end of the stroke, and thus apply force during the maximum power portion of the ram travel. That design of .50 caliber bullet can be swaged in the Mega-Mite press, provided you don't also try to use hard lead or a very thick jacket (over .035 inches for the walls, in copper). You might have trouble making an Ultra Low Drag nosed .50 BMG bullet because that calls for a long, heavy slug with a nose that is longer than half an inch, and will require considerable force early in the stroke. You might do it by adjusting the top punch up and down so you get a couple of swings at it, first forming it half way and then adjusting the punch down and forming it the rest of the way. But that is too much work for me. I'd rather get the Hydraulic press. With the most blunt nosed, soft lead bullets, a .720 caliber short bullet (under 1.5 inches) can probably be swaged, as can smaller ones. Lead wire extruders designed for the hydraulic presses will not work in the Mega-Mite. Practical lead extrusion takes full power from the start of the stroke, not just at the end. No matter how large you make the press, if it uses practical leverage a normal human being can operate, it probably will have about the same amount of final tonnage and power cycle. This means about half an inch of the final travel will give you 90 percent of the power. Making everything larger does not give you more leverage. All it gives you is a stronger tool, not a more powerful tool. Some people have a problem understanding the difference, and a few of them even make and sell presses with rather wishful thinking expressed in their specifications. Press Design ConsiderationsBear in mind that power output is just a simple physics equation: at any point in the stroke cycle, the instantaneous power available (or leverage to apply the power) is the force you can apply to the end of the handle multiplied by the ratio of how far the handle will travel (in an arc) to move the ram a given distance. This is an ideal differential calculus problem, but it can also be thought of logically without higher math. Lets say that you want to move the ram up another 1/10 of an inch (.1 inches). How far does the end of the handle travel to get that amount of ram movement? | |||
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With a press linked through a swinging toggle, you have a compound lever system that constantly changes the ratio of movement. As the handle approaches the middle of its stroke, you might move the end of the handle in a 1 inch arc to get 0.1 inches of ram travel. That is a ratio of 10 to 1. If you pushed fifty pounds on the handle, you would generate five hundred pounds of thrust on the ram. But as the ram gets to the end of its travel, the handle might swing another four inches while the ram only moved up 0.1 inches. At that point, you have a 40 to 1 ratio, so pressing the same 50 pounds on the end of the handle gives the ram a thrust of 2,000 pounds. If you need 2,000 pounds of thrust in order to start forming a long ogive, you may not have it early enough in the stroke cycle and there isn't a lot that can be done about it in a practical hand press. If you make the handle longer, eventually you reach a point where you can't reach the handle! With the Mega-Mite (and S-Press), we've maximized the arc length in two ways. First, we make the longest practical handle that can still be conveniently reached at both ends of the stroke. Second, and more important, we designed the toggle so it fits around the ram at the end of the stroke. This allows a full 180-degree arc, so you can input more handle movement with the same length of handle. Most reloading presses can only swing an arc of about 135 degrees. Thus, with a three-foot long handle, you can input force through a distance of 9.425 feet (length of the arc of half a circle with a radius of three feet) on a Corbin press, but only 7.069 feet if you put the same length handle on most reloading presses. The reloading press has a total ram travel of about four inches, as it must to handle rifle cartridge reloading. Four inches is 1/3 of a foot. The overall leverage ratio is 7.069 divided by 0.333 or 21.2. This doesn't mean you have a 21.2 mechanical gain through the entire stroke, of course, because the specific ratio depends on where you are in the stroke. But it gives you a nice comparison figure for overall performance. This assumes the use of a 3-foot handle, to make the comparison fair. Actually, most reloading presses have much shorter handles and so their leverage is even less. In the Corbin press, the ram travels 3 inches in the CSP-2 press. That is 1/4 of a foot. The overall leverage ratio or mechanical advantage for the press is 9.425 divided by .250, or 37.7. That is 16.5 more than the reloading press, or expressed as a percentage of improvement, the Corbin press has 178% of the leverage of a reloading press, assuming the reloading press were to be equipped with the same handle. In reality, it probably has close to twice the power since reloading presses have typically shorter handles. Building the press twice as large would not change this ratio, and would not change the power at all. It would only make the press larger and stronger. If the handle was moved in a bigger arc but the ram went a longer distance, by the same ratio, then no power is gained. We're using power to mean mechanical advantage, which isn't strictly true but amounts to the same thing for our comparison. Besides, if the press were made twice as large, you'd need to climb on a ladder and grab the handle, and then jump off to swing it through its full arc! | |||
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Making everything except the handle larger or longer would actually decrease the leverage. The Mega-Mite design is at the limit of practical power for a hand press, unless you want to add a crank and gears instead of a handle, so that the cumulative distance you move the crank gives you more input stroke for the same ram movement. An arbor press is a step toward a crank and gears (using a single drive rack and pinion gear). But the better answer is hydraulics. Adding gears and making you spin them for each stroke is too much like making ice cream with a hand-cranked freezer! If you have done that, you know how long it takes to get good results. Of course, electric motors do the job today. But adding an electric motor to a mechanical gear press has its own problems, which I discuss in detail in the chapters on mechanical press design in the book "Power Swaging". I won't repeat it all here. Roller Side-Bar Handle, CSP-2SHThe Mega-Mite press can be provided with either the long swaging handle or a shorter handle with a side-bar grip. For reloading and swaging operations that do not require maximum leverage, the short handle is convenient and easy to use. It reduces the amount of movement you must make with your arm on every stroke, at the expense of a lower mechanical advantage. Those who use the short handle are enthusiastic advocates. But some operations, such as long bullet draws or tubing jacket end-forming operations, or very large calibers, require all the leverage you can get in a hand press. For these jobs, the long handle (CSP-2LH) is required. Specify whether you want the short or long handle with the press. The other is always available as an option. Handles are easy to change. Most people who have the short handle also purchase the long one. Floor Stand, CSP-SThe Mega-Mite press is available with the same CSP-S Floor Stand as the S-Press. There is a separate set of bolt hole patterns in the top mounting plate of this stand, so you can use the same stand for either press (but not both at the same time). The CSP-2 Mega-Mite press, without stand, can be shipped by United Parcel or by Air Freight. It is not mailable by standard U.S. Postal Service. It can also be delivered by truck, and if accompanied by the stand then truck or Air Freight are the only practical delivery methods.Using the Knock-Out Bars The Mega-Mite comes with a set of knockout bars instead of using a steel pin passing through the ram to stop the movement of the internal punch and cause ejection from the die on the down stroke. The bars are hardened and ground steel. They are different heights, but the same length and width. The bars slip through a slot in the press ram, below a large steel spring surrounding the ram. The spring presses down on the top of this bar, and the internal punch rests on the bar. The correct bar to use is the one that, together with the length of the internal punch, brings the internal punch to the mouth of the die at the end of the down stroke. Internal punches come in different lengths. Longer punches are used for lighter or shorter bullets. Middle range lengths of bullets take | |||
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a middle length of punch, and the heavier bullets, which are generally longer, take the shortest punch. The knockout bar which makes up the difference in punch length is the one to use with any given punch. You can easily tell if you are using the right combination of knockout bar and punch: the face of the punch should come even to the end of the die on ejection (fully lowered ram position). If not, just change the knockout bar until it does. The ram needs to be raised so you can get the bar under the spring. Using the Retraction Pin and SpringSome type -H punches have a quarter inch diameter hole through the head, so that you can put a steel pin through the hole. The big spring around the ram goes on top of this quarter-inch diameter pin. The purpose of the pin is to let the big spring push down against the pin, which in turn pulls the internal punch down, keeping it out of the die cavity until you lower the ram to eject the bullet. Not every -H punch uses this "retraction pin" or has a hole for it. Those operations which use the bullet or core to push the internal punch down do not normally require spring retraction. But point forming dies, boattail forming dies, and certain other dies require that the internal punch be pulled down by something other than the insertion of the bullet components. In the case of a point forming die, the ejection pin (which is the internal punch) cannot be inside the open end of the jacket while it is being formed into a point (or else the pin would be trapped inside the jacket tip). The spring pulls down on the retraction pin, which in turn pulls down the internal punch, and thus keeps the wire pin portion of the punch out of the main die cavity until you need it for ejection. Reloading Adapter Kit, RLA-1-HThe CSP-2 Mega-Mite press is a very capable reloading press when used with the appropriate adapter bushing and ram extender/shell holder adapter. It can accept .50 BMG reloading dies directly in the head (if they are 1.5 X 12 thread). The RLA-1-H Reloading Adapter kit converts the press for use with regular RCBS shell holders and 7/8-14 tpi reloading dies. It also follows that you could use Corbin type -R dies for swaging in this press, or in the S-Press. You cannot use -M or type -S dies and punches in this press, however: the cost of adapters for all the punches and dies would exceed the cost of getting the right dies in the first place! 50 BMG Reloading and Priming (PT-50-H)The Mega-Mite is ideal for .50 BMG reloaders and bullet makers. Corbin also makes a special shell holder, the SH-50-H, which is threaded to fit into the top of the reloading adapter's ram extension. The shell holder is hardened, and glass bead peened, so that it will last and provide excellent grip on the big 50 case rim. One of the shell holders also comes with the PT-50-H priming tool, which is designed so you can use it in the ram of the Mega-Mite, for precise adjustment of the seating depth, and also leave it in place without adjustment for depriming! | |||
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To use the PT-50-H, first move the ram-to-toggle pin into the long stroke (reloading) position. Then place your depriming/sizing die in the press head. Place the knockout punch for the PT-50-H in the press ram, resting on a knockout bar. Adjust the hardened hex-socket screw in the upper part of the tool so that the primer punch protrudes the desired amount (you can fine-tune it later). Screw the priming tool body, with the shell holder in place, into the ram. Place a case in the shell holder, and run it up into the depriming/sizing die. Adjust the die to do its job of knocking out the primer and resizing the case according to standard procedure. The spent primer will fall through the shell holder, into the priming tool base, and out an angled port hole. A plastic cup or shallow dish, like a margarine tub, with a hole through the bottom to slip it over the ram, will catch the spent primers if you wish. Otherwise you can catch them as they come out of the priming tool. (At this writing, I'm thinking about providing a flexible polyethylene primer catcher to slip over the ram, and by the time you read this, it may already be included with the press.) Lower the ram part way, to free the case from the die, and slip it out. Hold the primer pocket against a power primer brush or clean it by hand, then with the ram slightly raised, put a new primer in the center of the shell holder. If the ram is raised slightly, it will drop into the hole. Slip the shell case back into the shell holder, and lower the ram. Then remove and inspect the primer, and adjust the setting of the hex screw so that the primer is set as desired. Once you have set the primer tool, it will maintain accurate primer depth. Arbor Press Adapter Kit, APA-2-HThe Mega-Mite press can also use the optional APA-2-H Arbor Press Adapter kit. This consists of two inserts, one for the floating punch holder in the press head, and one for the ram. Their faces are ground flat and polished, so that inserting them gives you the equivalent of a very powerful arbor press with the ability to adjust the feel or the power depending on where in the stroke the work takes place. For more "feel", adjust the floating punch holder lower. For more power, adjust it higher. Dies that were designed without threads, for use in an arbor press (benchrest style dies) can be precisely operated by utilizing the APA-2-H kit. Unlike an arbor press, which has only one fixed power/feel ratio for the whole stroke, you can select the degree of feel and the ease of use by adjusting the punch holder to the desired end-of-stroke position. Quick Change Punch Holder, FPH-QC-HIf you make bullet jackets from copper tubing, and the jackets are quite long, you may find that getting them in and out of the die requires adjustment of the punch holder on each stroke. This is slow and inconvenient. A better answer is the FPH-QC-H Quick Change floating punch holder. Using it is much faster and easier than constantly adjusting the punch holder up and down. Since the quick change punch holder is not necessary with short and medium length components, has | |||
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more parts and takes a little longer to set up, we do not supply it with the press. But if you run into a situation where removing the top punch quickly would make operation faster, it is a good option. Stripper Kits, SK-1-H or SK-2-HYou may have noticed a pair of holes with bearings in the top plate of the press, and matching threaded holes in the moving ram guide plate. These are used with the optional SK-1-H or SK-2-H stripper kits. The first is a pair of long threaded rods with a series of heavy spring clip pins through them at various points, and a heavy steel bar at the top joining them. The SK-1-H is used in certain jacket drawing operations, to provide a way to push down on a punch in the top of a drawing die and eject a component, or to hold a stripper plate below the draw die, through which a long drawing punch passes. The SK-2-H is similar but does not push down on an ejector. It suspends the steel bar across the path of the ram, so that the draw punch goes through a large (loose fit) hole in the center of the bar, on top of which is a snug-fitting thick bushing that does the actual stripping of jackets off the punch on the down stroke. To use either one, you simply adjust a pair of nuts on the threaded rods to hold the stripper bar at the right position, so that lowering the ram will allow the jacket to be stripped off the punch. Instructions for setting up the knockout operation are provided with the SK-1-H. Basically it is simply a matter of adjusting the rod position so that a solid steel bar across the top of the press pushes down on an ejector rod in the die. Most dies do not require a knockout rod and bar, because the component will either come all the way out the top of the die, or will strip off the punch on the down stroke. Generally, the SK-1-H stripper kit will come with one plate or bushing to fit a certain punch, and additional plates or bushings can be ordered for other punches. Unless you need it, there isn't any point in ordering one. It is a special purpose tool, which will be suggested if the tooling that we develop for you calls for it. But I thought you might be curious about those holes! They are "just in case", not something that everyone will use. Nothing is missing, just because the holes are there when you get your new press! Hydro-Mite Press, Model CSP-1HThe Corbin CSP-1H Hydro-Mite is the smallest hydraulic powered press Corbin builds. It is the same general size and frame as the S-Press, but is equipped with a 3/4 HP 120 volt AC remote controlled power system. The smooth, quiet operation makes the normally long jobs of jacket drawing, bullet reducing, or case sizing go quickly with almost no physical effort. The press isn't as well suited for bullet swaging as the other hydraulic or hand presses, however. I recommend it very highly for making jackets and other redrawing operations, but not so highly for bullet swaging. | |||
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Although the press can generate more force than hand presses, the main advantages are the lack of effort required (so that even disabled persons can perform long runs of production without becoming tired) and full power from the start to finish of the stroke. It is a linear power stroke rather than the log power stroke of a hand press, meaning that you can do drawing operations, lead extrusion, and other jobs which use the same power at the start as they do at the end. The press has the same caliber and length limitations as the hand operated CSP-1 because the same dies (-S) are used. But jobs that normally require adjusting the punch holder back and forth to get enough force at the end of the hand-operated stroke can be done in one pass without moving the adjustments. For this reason, the CSP-1H Hydro-Mite can produce more jackets per hour (and the operator does not tire nearly as soon). The Hydro-Mite is ideally suited to production runs of small parts, such as drawing .22 cases into jackets. Because you can generate sufficient power to easily pop a type -M die of nearly any caliber, it is not recommended that you use anything except type -S dies in the Hydro-Mite press. This is not to say you would break -M dies or you couldn't break -S dies. Any die can be broken with enough applied pressure, and pressure can be focused on a narrow point in any die by using hard materials which do not spread out and distribute the force until high levels of localized pressure are reached. This is why you can swage .375 rifle bullets from lead and copper jackets all day long and then break the die on a single attempt to form a solid copper .375 in the same die with the same applied pressure: the localized pressure at the contact point of that solid copper rod can exceed a hundred thousand pounds per square inch, whereas the same ram thrust spread out over the softer material contact area would result in perhaps 40,000 PSI localized pressure. But drilling a 1/8-inch diameter hole through the end of the solid copper rod, about halfway down the axis, allows the material some space to take up as it squeezes down in diameter, and thus reduces the pressure to a practical level. Hydro Junior, Model CSP-2HThe Hydro Junior press looks almost identical to the famous Corbin CHP-1 Hydro-press at first glance. You notice the colorful top, the color-coded indicator lamps and buttons, heavy chrome-moly ground and polished guide rods and space-age ram and guide plate bearings. The difference is in the additional logic and control circuits, transducers and sensors found in the Hydro-press. The purpose of the CSP-2H is to fill in the gap between the CSP-2 Mega-Mite hand press, which uses the same dies, and the more versatile CHP-1 Hydro-press. If you don't need to add automatic strip feeds, or semiautomatic stroke cycle, or let the press finish a bullet while you inspect and package the last one (giving you almost twice the production per hour), then the CSP-2H is a good choice. | |||
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With a 2,000 PSI drive pressure, adjustable down to 500 PSI, and position detectors for the ram, you can set not only the correct pressure to use, but also the ram position at the top and bottom of the stroke. This becomes important because it means you can define the stroke, adjusting for various die and bullet lengths to give you optimum speed and minimum wasted ram travel. If you want to extrude lead wire, make 12-gauge or 10 gauge slugs, stamp out medals or coins from thick strips of silver, copper, brass, or bronze, make copper tubing jackets up to .125 inch wall thickness, or form certain kinds of solid copper bullets, then the CSP-2H may be the most economical choice. If the caliber is larger than .458 or the material hardness exceeds Bhn 10, or the bullet length is over 2 inches, such as some long .50 BMG bullets, choose between this press and the CHP-1 Hydro-press. There is no other reason besides cost not to get the CHP-1. The CSP-2H is identical in power, stroke, cabinet and head design and takes the same dies and punches (H). The CHP-1 adds adjustable ram speed, automatic pressure reversing, programmable stroke controls, automatic loading position, adjustable top-of-stroke dwell time, stroke counter, interface and control for automatic strip feeds, ability to use the semi-automated processes such as jacket making from strip with the first two steps combined into one automatic operation, and the speed of having certain parts of the operation initiated and run without further operator manipulation (so you can do something else during the cycle). Instructions for operating the CHP-1 press are found in the book "Power Swaging". The same instructions apply to the CSP-2H, except for those controls and features that are not present, of course. The stroke is adjustable up to 6 inches, with configurable start and end points set by position sensors. The system pressure is 500 to 2000 PSI, adjustable, with top panel gauge readout. This is applied to a 3.25 inch cylinder, for ram thrusts up to approximately 20 tons. This can translate to hundreds of thousands of pounds of internal die pressure, depending on the die bore and contact area. The book "Power Swaging" gives tables of maximum internal die pressure versus gauge pressure readings, to help avoid die breakage. The computer software program "DC-DIES" is a fast, easy way to calculate the breaking point of any die, figure ram tonnage and internal die pressure from the gauge pressure, in any caliber of die. The CSP-2H weighs about 300 pounds and is shipped only by truck or Air Freight. It can be exported, using a 240 volt 50 Hz or 220 volt 60 Hz supply. The domestic version uses 120 volt 60 Hz single phase power (standard household current) at 20 amps maximum for the 1.5 HP motor. Common Questions about the CSP-2HBecause the book "Power Swaging" is primarily about the use of power presses and serves as an instruction guide for the Hydro-press and Hydro Junior, I will not dwell at length on the operation in this book. But I should address some of the most commonly asked questions about the press. | |||
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How much maintenance does it require? Virtually none. The system uses a vertical mounted cylinder with no side drag on the seals, and the hydraulic circuit is a closed system with recirculation filter. People such as Swift Bullet Company who purchased these presses in their start-up stages, many years ago, have used them to make millions of bullets with only cosmetic wear to the finish, sometimes an early switch or position detector failure, minor items such as the indicator or work lamp bulbs. By and large, if a person stays out of the cabinet and does not play with the design, take the precision hydraulic components apart and get dirt into the system, the presses will run decades with no more than indicator lamp replacement. What has failed? Very few presses ever have a problem, but of those few which have (over more than 20 years) the main items which were replaced have been the solenoid valve (direction control valve for the cylinder), the two-stage hydraulic pump (rarely), and the single-phase 60 Hz 1.5-HP motor. From damage or misuse, the main item of failure would be the position transducers (normally from someone adjusting them to stick so far out that the moving ram strikes one). But in most cases, the failure was either right away and covered by warranty, or it was after 10 years or more of hard use, well within the normal range of mechanical things. Do you need spare parts, then? I would not buy spare parts unless you are located in a land where it is difficult to get air shipments, or the project is so critical or profitable that being down a few days would cost more than the value of the parts and air shipment. The failure ratio is so low that most people will never need to replace anything for decades. If you really use the machine hard, such as two shifts a day and six days a week, then maybe getting a second machine would be sensible. We do have a spare parts kit, which includes indicator lamps, relays, and the solenoid valve, plus a spare position sensor and dwell timer. But every year the reliability of the components seems to improve, with new solid state electronics replacing more of the early components. Even the first machines were very reliable. The ones we make now are remarkably solid, and I don't say that just to sell them. If I thought you needed parts to keep them going, I'd say so. It doesn't hurt General Motors and Ford that there is a big aftermarket for parts. But I just can't honestly say there is much to go wrong, based on what really happens to the ones we've sold all these years. Do you need special hydraulic fluid, and how often do you change it? You need to use the right fluid, but it isn't that special. It is the same as Chevron AW-40, a standard non-synthetic anti-foaming hydraulic fluid. Do not dump brake fluid or other nonspecific types of hydraulic oils into the machine! If you can't find an equivalent to the Chevron fluid, from Mobile or BP or whoever else is handy, then contact us and we can ship you a gallon or two. But having said that, the only time I've found it necessary to change the fluid was in cases where the machine sat in a cold unheated building and was subject to sweating and condensation when the heat was cycled on and off during the work week. Or, if a person decided to tear into the guts of the machine and take the thing apart, and lost fluid in the process, that would be another case where you need to add fluid. Or, in one final instance, where the machine was dropped or tipped over | |||
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during shipping, contrary to the instructions on the box that say clearly "DO NOT TIP PAST 15 DEGREES" and have a 15-degree angle printed on the box to illustrate how much that is. There is a filler and breather cap combination, just at the front of the machine, inside the front panel, on top of the hydraulic tank. The entire lower portion of the machine is a hydraulic tank. It holds about six gallons of fluid, although we may make design changes so follow the information that comes with the machine if it differs from this. You would seldom if ever need to change the fluid. If you did, there is a plug at the rear, near the bottom, that lets the fluid drain out. But unless it is contaminated from something dumb that someone decided to do to it, or unless it was subject to a lot of condensation that might have put water in the tank, odds are you could run it forever on the same fluid. Most people do. Do you need special power wiring? No, but you need | |||