There’s a lot going on when you squeeze the trigger of an AR. When the sear breaks, you better know that your ammo is up to the task, especially if you handload. Add these tips to your loading repertoire to build more consistent, reliable and accurate ammunition.
1. GOOD NECK TENSION: Consistent neck tension refers to the case mouth applying the same pressure and friction to the bullet from one round to the next. Consistent neck tension results in a repeatable powder gas pressure curve, and similar muzzle velocity and trajectory—meaning your slugs will land in the same place. Equally as important, a consistent pressure curve means that your AR will cycle the same from shot to shot. Military loads, and some factory loads, attempt to achieve this by crimping their bullets in the case.
“Crimping the case is one option, but it means you will distort an expensive bench-rest bullet,” said John Paul Gangl, owner of JP Enterprises. He went on to say that new brass cases, once-fired cases, or at the very least, cases of the same headstamp, should only be used for reloading.
2. CASE ANNEALING: Repeatedly firing and loading a brass case causes the case neck and shoulder area to become work-hardened and brittle. A telltale sign is that the case necks start to crack on firing.
One way to extend the life of your cases is to anneal them. The simplest way to accomplish this task is to use a propane torch to apply the correct amount of heat and then drop the case into a cool bucket of water. Fancy case-annealing compounds are available that turn a certain color to indicate the proper amount of heat has been applied.
When I’m annealing cases, I don’t have time to waste on this extra step. My method is to anneal in a darkened room. This way, I can remove the case from the heat source just as it begins to glow red. Don’t overdo it, since too much heat will over-soften the brass and reduce case life, too.