Trimming cases to length is important particularly for semiautos, and this is just one caseprep step that contributes to reliable handloads.
February 22, 2024
By Joseph von Benedikt
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Decades ago, I attempted to shoot a pronghorn buck with my reproduction Henry 1860 lever action chambered in .44-40. It was a very doable shot even with the iron sights—just 45 yards or so. When the hammer fell the rifle emitted a weak “pop,” and the buck ran off.
Somehow, at the ripe age of 15, I’d neglected to put powder in that particular cartridge case. That was a glaring mistake, and one that a savvy handloader should never make. There are others that are less obvious. Here are a few techniques that help minimize the potential for handload-induced malfunctions.
For starters, here’s a mantra that’s popular among survivalists: Your most important tool is right between your ears. Surviving a lifetime of handloading calls for good focus.
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1. Minimize Distractions Minimize distractions. Turn off the music, or at least keep it low. Don’t chat with friends or reload when the kids or grandkids are pestering you to play. Don’t load ammo when you’re frustrated, angry or super tired. Anytime gunpowder, primers and projectiles are involved, be sure you’ve got your full wits about you.
2. Inspecting Cartridge Cases Cartridge cases are the punching bags of the reloading world. Shooters use them hard, and often use them past their prime lifespan, and it’s important to inspect each case prior to reloading it.
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Look for cracks around the neck. Unfortunately, cracks often happen at the time bullets are seated, so you may have to discard a fully processed, freshly loaded case. Pull the bullet and save the powder, but the primer and case are lost causes.
More commonly, cases fatigue around the circumference of the case just ahead of the web, which is the thick, strong base portion. Look for bright, fresh-brass-colored rings beginning to show around the case about 3/8 to 1/2 inch up from the base. That’s an indication the case is thinning there.
Don’t use such cases for anything important. A case-head separation—where the front portion of the cartridge case breaks off from the base and remains inside the chamber when you extract the empty—puts an abrupt halt to your hunt, match or range trip.
If indications are minimal, you may get another loading or two out of such cases, but they’ll need to be discarded soon.
Also, look for excessive dents. These can be caused by the harsh function of an aggressive semiauto action or by ejected cases impacting on rocks. Small, soft-edged dents will iron out when fired, but serious dents will often crack.
I once watched a friend pound on the charging handle of his expensive AR-10 with a two-by-four during the middle of a match. He’d neglected to trim his brass to length before loading, and a case had jammed with the bolt halfway into battery. Overall length of that case was more than the length from the bolt face to the end of the chamber, and the brass wedged tight.
3. Trimming Brass to Length If you’re loading ammo for a semiauto rifle, always trim your brass to length before loading. Yep, every firing. Cases fired in semiauto rifles—particularly AR-types—tend to stretch more than cases fired in other action types.
In addition to maximizing reliability, trimming cartridge cases to length optimizes accuracy by ensuring that each bullet exits the case mouth at the same point, and with a good, square release.
4. Sizing Brass Handloaders screw up reliability via sizing more than most other steps. There are a few ways this can happen. For starters, cases can be insufficiently sized. If fired cases are left oversize, they won’t chamber. This usually occurs when attempting minimal sizing in order to achieve maximum accuracy.
Neck sizing is all very well until a case “grows” enough over the course of several firings that the shoulder begins to bind when the bolt is closed. Every so often, it’s necessary to full-length size. And, of course, always full-length size brass that’s been fired in a different rifle.
Cases can be sized too aggressively as well. In this situation, the shooter often won’t realize there’s an issue until a case ruptures and separates about a half-inch in front of the base—the case-head separation I just mentioned.
Often the cause is that the case has been overworked. If your chamber is on the long side and you aggressively resize your brass to minimum length, that brass case will have excess headspace. Every time you shoot, it has to stretch to fill the chamber, and it will quickly thin around the base. A rupture comes next.
5. Primer Pockets: Avoiding Hot Loads Similarly, primer pockets can be overworked from a diet of hot loads, and in fact a loose or semi-loose primer pocket is a sure sign that chamber pressures are high. It can be tempting to save and continue to use cases with primer pockets that are just sorta loose. Don’t do it. Adjust your charge weight down.
How does this affect reliability? A near-loose primer can migrate rearward or even fall out in the magazine during recoil from previous shots. That’s a recipe for a hard-to-clear jam, not to mention a cartridge that fails to fire.
6. Charging the Case And then there’s the issue of charging a case, illustrated by my story at the beginning of the article. If you handload long enough, eventually you’ll find a cartridge case that somehow, impossibly, managed to escape being charged with powder.
Don’t charge and seat bullets individually. Charge a full batch of prepped cases, then shine a powerful light into the case mouths and scrutinize each one carefully. Check to be sure it has powder, and that powder is the same level as all the others around it in the loading tray.
7. Chamfering Cases Here’s the other most-problematic handloading step. Screwing up bullet seating can result in a bulged case or a tilted projectile or a rolled case mouth—all of which will prevent the cartridge from entering the chamber.
The most important step to preventing issues is to cleanly and generously chamfer the inside of your cartridge case mouths with a low-drag chamfer tool. Do this every time you trim to length. This prevents bullets from catching and hanging up or dragging as you seat them.
Non-chamfered cases can also shave copper from bullet sides—a sure way to destroy accuracy. In extreme cases, those copper shavings can lodge in chambers or against bolt faces and become an obstruction.
Non-chamfered cases also sometimes collapse or bulge slightly under the pressure of the bullet’s base attempting to force its way into the case mouth. Usually, the collapse and bulge occur at the case shoulder, and usually it’s enough to prevent the cartridge from chambering.
8. Crimp If you crimp—necessary for ammo being used in tubular magazines or fired in heavy-recoiling rifles—trim to length first, so you achieve a consistent crimp. Otherwise, accuracy suffers. Apply the crimp as a separate step, not concurrently as you seat the bullet. And don’t over-crimp. An enthusiastic crimp can collapse and bulge case shoulders, which will prevent those cartridges from chambering fully.
9. Using a Chamber Simulator Gauge A lot of reliability headaches can be headed off by using a chamber simulator gauge such as the Ammo Checker by Lyman to test and ensure each handloaded cartridge will cleanly chamber. In a pinch you can go to the range and—while keeping your muzzle pointed downrange at the berm and maintaining safe practices—cycle your handloads through the actual firearm you’re going to fire them in. This can scratch up your cartridges and requires careful handling, so I prefer not to perform actual chamber checks—with one important exception: I do check every single round through my rifle when preparing to hunt dangerous game.
10. Taking Care of Your Ammo Last but not least, take care of your ammo. You put time, money and hopefully a lot of thought into carefully crafting those handloads. Don’t leave them on the hot dash of your pickup truck. If you grab a cartridge and fire it while it’s scorching hot you may experience heat-induced overpressure, resulting in a stuck case.
Don’t leave cartridges in a leather cartridge belt all year, where they’ll build up a green layer of corrosion that can prevent them from chambering. Don’t leave them in open-topped boxes where dust and grit will build up. That’s hard on chambers and barrels and can prevent smooth chambering.
When handloading, keep your focus, use good technique, and never skip steps for the sake of speed or convenience. You’ll build ammo you can trust.
