RMAC 2026 is June 23–28, held at the Garth Killpack Shooting Range in Hobble Creek Canyon, Utah — one of the most technically demanding venues in competitive airgun. Canyon winds that shift directions mid-stage. High-angle targets up the mountainside. Steel from 150 to 450 yards. This is not a casual outing. This is the hardest test in the sport.
Last year, Corbin slugs owned the PRS podium. 1st, 2nd, 3rd — all Corbin. Eight of the top ten finishers. That wasn't a fluke. That was the product of decades of precision swaging, hydraulic forming consistency, and bore-matched geometry that no cast or molded slug can replicate.
Now we're raising the stakes. For 2026, we're not just defending the PRS podium. We're going after Big Bore.
Big Bore Is a Different Game — And We Came Prepared
The RMAC Big Bore Slug Challenge is its own world. Targets out to 450 yards. High-angle shots up a canyon mountainside. Two power classes — Light Class (140–240 ft-lbs) and Heavy Class (240 ft-lbs and above). The rules are strict: no rifle sharing, one spotter per shooter (for wind calls only), and zero margin for being unprepared. If you're not ready when it's your turn to shoot, you don't get points.
That last rule is worth reading again: if you're not prepared, you don't get points.
That's not a warning. That's an invitation. Because Corbin doesn't show up unprepared. Preparation is literally what we do — in the shop, at the press, and on the range. Every slug we load into a competition rifle has been hydraulically swaged to bore-matched tolerances, measured against spec, and iterated until the numbers are right. That discipline doesn't stop when we zip up the rifle case.
The New Slugs: .308, .357, and .457
This year we're fielding three new big bore slug designs — each purpose-built for the RMAC environment and each representing the best work we've done in its caliber class.
.308 — Bridging Precision and Big Bore Authority
The .308 has always straddled the line between precision small bore performance and big bore stopping power. Our new design pushes deeper into match territory with a refined nose profile, higher BC, and a weight configuration optimized for long-range energy retention. At 150 to 300 yards — the range where the .308 Big Bore class does most of its work — this slug shoots flatter, drifts less, and delivers the kind of group consistency that wins stages.
.357 — Built for a Class That's on Fire
The .357 big bore division is one of the fastest-growing categories in competitive airgun, and for good reason. The platforms are powerful, increasingly accessible, and the caliber itself rewards shooters who bring the right projectile. Our new .357 slug was designed from the ground up for the RMAC environment: higher sectional density, refined bearing surface, and a BC number that outpaces anything else in the class. If you're running a .357 big bore platform at RMAC 2026, this is what you want in the magazine.
.457 — Where Big Bore Gets Serious
This is the caliber that separates the serious competitors from everyone else. The .457 demands the most from a projectile — the trajectory is steeper, the wind drift is real, and at 400-plus yards up a canyon wall the margin for error is zero. Our new .457 is the heaviest, highest-BC big bore slug we've ever produced. It represents everything Corbin has learned across five decades of precision swaging — applied to the caliber that asks the most of the shooter and the projectile both.
Iterations and Practice: This Is How We Work
Nobody wins RMAC on instinct. The canyon at Hobble Creek doesn't care about your reputation. The wind does what it does. The targets don't move closer because you've been shooting airguns for twenty years.
What wins competitions is preparation. Repetition. Getting on the range and shooting the same round under different conditions until you understand what it does in wind, at angle, and under pressure. Knowing your dope cold. Having your air tanks topped, your scope dialed, and your chart memorized before you ever step to the line.
At Corbin, that same philosophy lives in the shop. Every new slug design goes through iteration cycles — geometry changes tested, BC measurements taken, weight configurations evaluated — until the sample we pull matches the specification we set. We don't release a product because it's close enough. We release it because it's right. And then we run it again to confirm.
The three new big bore slugs we're bringing to RMAC 2026 came out of that process. Weeks of engineering and live-fire evaluation. Multiple geometry iterations. BC numbers we hadn't reached before in these calibers. The kind of consistency that only comes from hydraulic swaging under controlled conditions, with the same tooling, the same alloy, and the same hands accountable for the result.
What RMAC 2026 Demands
The Slug Challenge at RMAC isn't a static bench event. You're shooting steel at mixed distances, high angles, with a single spotter who can only tell you where the wind is going — not where to hold. Your preparation has to be complete before the event starts. Scope data. Dope charts. Air management. All of it locked in before June 23rd.
RMAC organizers are direct about this: there is no time during the event to figure out your setup. They mean it. The schedule is packed, the stages run tight, and the shooters who succeed are the ones who treated preparation as part of the competition — not a warmup to it.
That's exactly how we approach slug development. The range work isn't separate from the manufacturing work. It's the same process. You're not ready to compete until you've put in the reps, verified the data, and confirmed the result. Then you do it again.
The Podium Is the Goal
We swept the PRS podium at RMAC last year. That result came from building better slugs, iterating faster, and understanding what the competition environment actually demands from a projectile. The same thinking — applied to the Big Bore classes — is what produced the .308, .357, and .457 slugs we're bringing to Utah this June.
We're not coming to participate. We're coming to podium.
RMAC 2026. June 23–28. Hobble Creek Canyon, Utah. Let's see what these slugs do at 450 yards.
RMAC 2026 Big Bore Prep - Corbin Is Upping Its Game and Its Aim