Written by Sierra Bullets Media Relations Manager Carroll Pilant
The tips below continue Easy Ways to Save Yourself Headaches at the Range (Part 1)
Five: Check Your Crimps
Rifle and handgun cartridges that are crimped with a roll crimp are often not trimmed to the same length as they should be. The short cases don’t get any crimp, the correct length cases crimp perfect and the long cases has a bulge right below the crimp that either keeps them from chambering or makes them really hard to chamber, depending on how much bulge there is. You can get some really erratic velocities also. Having the body of your seating die too low will also cause bulges either on the shoulder or neck. On taper crimp dies, the reloader sometimes doesn’t even get the case mouth bell smoothed out of the case and you can feel it actually still flare out. This does nothing to help hold the bullet firmly and will not feed smoothly into the chamber. Others will put the crimp so tight that it actually damages the bullet. The case mouth walls should feel smooth when you run your finger alongside of it. One way I like to check my crimp on a center fire pistol is to load about 3 rounds, measure the first one I put in the magazine, fire the first 2 letting the 3rd round chamber. Then I eject it and measure it to make sure it is the same length that it was when I measured it originally. If it isn’t, I adjust my crimp slightly more and repeat the process until the bullet stays the same length.
Six: Be Sure to Chamfer/Debur All New and Trimmed Cases
Not chamfering the inside/outside of the case mouth on bottleneck cartridges often causes problems also. When the case mouths are left square, there is often a tiny ring of copper gets shaved off the base or top of the boat tail on the bullet. Sooner or later one of those little rings will find their way into a chamber and will keep a round from chambering completely. Guess where they beat the gun at again.
Seven: Use the Correct Tool to Remove Crimped In Primers
A lot of surplus military cases available have crimped in primers. Besides being a little rough on decapping pins, they sometimes cause problems removing the crimp. Several companies make tools for removing the crimp such as the one that Dillon Precision makes that swages the primer pocket and leaves smooth rounded edges. Some others like Lyman, actually cut it out and faintly put a rounded edge on the mouth. A problem arises though when the reloader tries to use a case mouth chamfering tool to bevel the crimp out. They get to much bevel on it and the primer has a lot of unsupported area that stands a chance to rupture. (See the left side of the photo.) This not only spews gas and etches the bolt face, it can also get gas and metal particles into your eyes. If you are going to process crimped in primers, be sure to use the correct tool.
I could go on and on but hopefully this will help some of you that are having these problems cure them. As I was rummaging around making cases for these photos or looking thru junk ammo, I thought of several other problems. We will cover them another time. See you on the range. Hopefully you aren’t having to beat your rifle open!