There are three ways to make bullets:

Swaging is the opposite of drawing. When you DRAW a bullet or jacket, you push it through an open ring die that reduces the size. When you SWAGE a bullet, you expand it to a slightly larger size in a pressure-sealed die cavity. You can draw down, but you always swage up in diameter.

Pressures in the 10,000 to 50,000 psi range are applied with a powerful high precision press. The pressure is applied through hardened, high strength punches which compress the material inside the diamond-lapped die. This causes expansion in diameter to the exact shape and size of the die cavity and punch ends, transferring the precision finish of the die and punch to the bullet. 

The process can be used to make lead or jacketed bullets, even lead-free bullets from ductile mixes or powders, in virtually any caliber and shape. Pellets, shotgun slugs, pistol and rifle bullets, round balls for muzzle loaders -- nearly any kind of bullet -- can be swaged in one or more steps, depending on the design. For more than 50 years, Corbin has been the world's foremost manufacturer of bullet swaging equipment, dies, supplies, and information.

Bullets can be made of one material such as solid lead, copper or a powdered metal mixture, or they may be "jacketed", meaning the core material is covered by a "skin" normally made of relatively thin copper or brass alloy. The "jacket" can be purchased from Corbin, or made at home from copper tubing or from flat copper strip, with Corbin jacket-making tools.

Jackets are always slightly smaller than finished bullet diameter, and are expanded by the high internal pressure applied in "seating" the core. Jackets are not "put on" a bullet. They are expanded and formed with internal pressure against the ductile core material, until they are stopped by the diamond-lapped die walls. They take on the shape, diameter, and even the finish of the die surface.

Jackets protect the core material from excess friction, deformation from gas pressure in the barrel, and control performance on impact. They also protect the bore from fouling or melting of the core material from friction and heat. Both jacketed and non-jacketed bullets can be swaged easily with Corbin tools. In many cases, the same tools are used for either style, perhaps with slightly different punches.

The Problems with Casting Bullets

1. Safety Hazards

Casting involves working with extremely hot molten metal, which poses significant safety risks. The main dangers include severe burns and lead pot explosions. Even a small drop of water or an insect falling into the pot can cause an explosive reaction, sending molten metal flying. Unlike casting, swaging is a cold metal forming process that eliminates these hazards.

2. Limited Flexibility

Each bullet shape, caliber, or weight in casting requires a new mould, making it difficult and costly to experiment with different designs. Custom shapes necessitate custom moulds. Swaging, however, offers almost unlimited possibilities with a single swage die, allowing for various weights and styles. By combining different punches and dies, swaging can produce unique bullet shapes that casting cannot achieve.

3. Time-Consuming Process

Casting is a labor-intensive process that involves melting lead, heating moulds, casting, inspecting, rejecting culls, sorting, sizing, lubricating, and cleaning up. This makes it challenging to produce a few bullets on short notice. Swaging, on the other hand, can produce ready-to-shoot bullets in seconds using a roll of lead wire and a swage die, without the need for sizing, lubricating, or handling hot tools.

4. Design Limitations

The basic design of a cast bullet is a solid piece of lead, restricting the possibilities for innovative designs. Casting cannot easily accommodate jackets, partitions, shot-filled cups, multi-part bullets, bonded cores, hollow-base/hollow-point combinations, and other complex designs. Swaging allows for these advanced features and more, enabling the creation of highly specialized bullets.

5. Inaccuracies and Defects

Casting can result in inaccuracies due to trapped air or gases that form unwanted internal bubbles, affecting weight and balance. The high temperatures involved in casting lead to thermal size variations in each bullet. Mould halves that pivot introduce play and misalignment. In contrast, swaging uses precise round holes in solid dies, maintaining consistent dimensions without the need for heating and cooling. The high pressures used in swaging eliminate voids and trapped air, ensuring greater accuracy and consistency in the final product.

Why Major Ammo Makers Swage Their Bullets

Major ammunition companies, benchrest bullet makers, and anyone seeking the most accurate bullet possible use swaging, or pressure-forming. Unlike casting, swaging does not involve heating molten metal, eliminating the risks of toxicity, burns, or fire. Swaging also avoids the heat-induced dimensional changes, wear, and misalignment associated with split molds, as well as the out-of-roundness caused by exposure to varying temperatures.

Swaging is highly versatile, allowing for multiple variations with a single set of dies. One swage die can produce virtually any bullet weight within a specific diameter, equivalent to thousands of molds. You can even make your own jackets from materials like copper tubing or fired .22 cases, creating bullets that outperform commercially available options by precisely controlling the weight, shape, and style for optimal results in your firearm.

Swaging is ideal for high-volume manufacturing with consistent bullet quality. Leading bullet manufacturers such as Sierra and Winchester use swaging. Speer ads highlight precision swaging as their production method. Swaging has long been the preferred choice for commercial jacketed bullet production, except for electro-plated lead bullets or CNC-turned copper or brass rod bullets, many of which are re-swaged in Corbin dies to ensure precision diameter and finish.

Corbin Swage Tools Work For You, Too!

For years, many hand loaders were under the impression that swaging was too expensive or complicated for them. The myth has been repeated over and over, sometimes by those who would prefer that you remain unaware (since then, it would be obvious that you could make the same product which you now pay another party to swage).

In the years just after the Second World War, right up until the mid-1970's, there was in fact some truth to this. Bullet swaging equipment was, at one time, only built for the benchrest shooter at high relative cost. World records were set by bullets swaged in these dies. A few firms tried to offer low cost versions but the result was typically poor, and nearly all of them went out of business eventually.

Partly because of the people who tried to cut corners and make cheap swaging tools, swaging got an undeserved bad reputation among shooters who had only tried the cheaper tools. (The same is true today: a handful of low-end producers do in fact make cheaper versions of Corbin tools, even copying the nomenclature and catalog numbering system. But it has always been easier to copy terminology than quality.) But over the past 50 years, Corbin's swaging equipment has become the world's leading standard for serious bullet makers, defense suppliers, and custom bullet firms.

How Does Swaging Work?

Several books have been written about bullet swaging, without exhausting all the possible uses or bullet designs. So rather than try to list every possible kind of bullet you can make, let's just take two examples to illustrate the basic tools:

A "die" is the cylinder which holds the bullet material, in a cavity or hole of the desired diameter. A die is equipped with two punches, one at either end. In a swaging press, the die screws into the press ram. For Corbin swage presses, the dies are either -S type (for the smaller S-press) or -H type (for the larger CSP-2 Mega Mite or the powerful Hydro-Press). One end of the die is threaded to fit into the top of the ram. The die moves up and down with the ram to swage the bullet. In a reloading press, the die fits in the press head in a die holder with a captive internal punch.

A "punch" is a solid rod fitted to the die cavity, which seals pressure and forms one end of the bullet or at least ejects it (in a point form die). Punches are of two kinds: internal or external.

Internal punches stay in the die during operation, sliding up and down to eject the bullet. In Corbin swage presses the internal punch fits inside the ram. One end of the punch (the "head") rests upon a "ledge" or shelf created between two diameters of axial holes through the ram. This is what positions the ram in the die when the bullet is being formed.

External punches for Corbin swage presses fit into a punch holder (FPH-1-S or FPH-1-H depending on size of press). The punch holder fits the threads in the press head (the top). Turning the punch holder to move it up or down adjusts how far into the die the external punch will go at the top of the stroke. This is how adjustment is made for weight and length, amount of tip closure, and so forth. For a reloading press, the external punch fits into the T-slot in the ram, which normally accepts a shell holder.

The Lead Semi-Wadcutter (Cat.No. LSWC-1-S or LSWC-1-H) is most simple kind of straight hole swage die for making a finished bullet in one stroke. A straight-hole die has punches which are a close, sliding fit to the bore or cavity. They seal pressure and keep the lead or other material from squirting past the punch, or "bleeding" as it is called. A SWC nose shape of any sort can be machined into the end of one of these punches. Shape can be round, or conical, or truncated conical, flat, or with a slight bump to make a "button nose" wadcutter. The important factor is that any cavity machined into the nose punch MUST have a reasonably thick edge, at least 0.015 inches, to withstand the pressure of swaging and then sliding along the die bore. Pressures of 20,000 psi and more are common. Thinner edges on the punch would let it crumble or be pulled off like foil.

Because the edge must be there, on a SWC type nose punch, the resulting bullet cannot simply blend in one smooth curve from full diameter into a nose shape. It has to stop at the shoulder created by the punch end, and then the lead nose is formed in the punch cavity. But one stroke of the press results in a finished bullet. The LSWC-1 die has bleed holes around the circumference, so that once you set up a given insertion depth of the external punch, a specific volume of lead is left inside the die and the rest has to spurt out through the bleed holes. That lets you adjust the weight just by moving the top punch up and down in its punch holder.

A jacketed bullet could be made in the LSWC-1 die except that the jacket would cover the bleed holes. So a two die set is used instead, consisting of a smaller bore size bleed die which is called a "core swage" die, or CSW-1 and a larger bore (actual caliber size) straight hole die without bleed holes, called a "core seater" or CS-1 die. The combination of these two dies can be ordered under a single catalog number JSWC-2, with -S or -H added to indicate the press type.

If you do use a jacket on the bullet, the jacket length must be short enough so it does not go past the shoulder. Otherwise the jacket end and the punch edge would mash together and crush the jacket. The jacket edge has no way to "jump over" the punch edge. That is what defines, and limits, the SWC type die. You can use more than one nose punch in succession, including a big hollow pointing punch and then a round nose or Keith nose punch pushed slightly less far into the die. The combinations of different punches and how far you adjust the second one to partially reform the shape provides a great deal of experimental possibility. It's part of the fun of swaging to see what you can create.

The basic steps to make ANY bullet with a smooth ogive is to swage an exact weight of lead core in the CSW-1- core swage die, put this core into a jacket and seat it in a CS-1 core seat die (or in a RBT-2- rebated boattail base forming die set, which is discussed on another page), and finish the the ogive shape by pushing this jacketed cylinder (seated core and jacket) into the PF-1- point forming die.

So the steps to swage most bullets (flat base, open tip style) are:

The Source Behind the Scenes

For decades, Corbin Manufacturing has been quietly supplying high-quality equipment for the world's top custom bullet makers. Prices compare favorably to casting, especially when you consider that a single set of swage dies can make an almost unlimited variety of bullet weights and styles, and when you are finished pulling the handle of the press, you are DONE! No further sizing, lubricating, inspecting, rejects... only perfectly swaged bullets of precision diameter and weight, every time!

Carefully hand-built dies and individually machined swage presses made in the Corbin die-works represent the highest standard for professional or hobby bullet swaging. Since the beginning, handloaders and experimenters, businesses and defense agencies have lined up to get their names on the delivery list for Corbin dies. Demand has been so great that delivery took two to three years! (Today, from our new die-works, only about 10 percent of "standard" tools take longer than 90 days to build, and most custom tools are shipped within six months or less, depending on the current number and complexity of pending jobs.)

Corbin has become the world's leading source for bullet swaging partly because: (1) Corbin developed the semi-custom production method for swaging equipment, making it possible to offer every caliber from .142 to 1-inch projectiles both in custom designs and off the shelf, without having to design every swage set from scratch, and thus greatly reduced the cost of high quality tooling, and (2) Corbin offers a virtual one-stop shop for everything associated with bullet swaging, including more information (including eight books) and design software than had ever been assembled previously (or since) from any other source.

Corbin makes a wide range of presses and dies, starting with die sets you can use with an existing cartridge reloading press, right on up to floor-standing hydraulic swage presses that can form the most exotic hard lead or jacketed bullets, ranging from .14 caliber, 20-grain varmint wreckers right on up to .700 caliber, 1200-grain elephant stoppers and 1-inch cannon projectiles! Airgun pellets, fragmenting pistol bullets, or shotgun slugs -- virtually every bullet design you can imagine, is being made on Corbin equipment right now!

Corbin is the Professional's Choice

Corbin has spent years developing and producing the finest quality swaged bullet manufacturing tools for the custom bullet maker. From A Square to Trophy Bonded, there are literally hundreds of custom bullet makers who use Corbin equipment. Their results -- and the results of those who shoot and hunt with their bullets -- speak for themselves. Nearly all custom bullet firms in business today either use Corbin equipment or got their start with it! Armament laboratories and defense contractors around the world use Corbin presses and dies for their prototype development work and short runs of special projectiles. Corbin sets the standard for professional bullet making equipment of the highest precision and quality.

Thousands more bullet makers and competition shooters who enjoy making bullets for just themselves or a small circle of friends. They know that using Corbin swaging equipment means success -- success in terms of tighter groups, better stopping power, and saving (and making) money! At Corbin our motto is "We Manufacture Success." Whether your interest is in loading the most match-accurate bullets that can be made or in becoming a top-quality custom ammo maker, Corbin can help you achieve success.