Has anyone experienced primers in 45acp rounds back out of their own accord? A friend claims he loaded some a few years ago, claims the primers were properly seated, and took them to the range recently to discover the primers in some had backed out. My first thought was they hadn't been fully seated, but he claims otherwise. I was able to seat one fully without any undue resistance, and it stayed seated. Any thoughts? Thanks. CB.

Sounds like pressure may be involved here. Like a bullet with light neck tension and no crimp that pushes out somewhat due to temperature changes. JMHO...

Ken....

Ken;
Thanks for the reply. I would have thought that air pressure would have moved the bullet forward (given the surface area of the base vs. the size of the primer hole), esp in a case without a heavy roll crimp. In 30+ years of reloading, I've never seen a primer back out under internal air pressure before. My initial thought was he was less vigilant than he thought when seating the primer in the first place.... Doug.

i would guess that either the primer pockets are a bit loose, or he is using the lemming brand of primers

What powder? Some here have reported that heavily compressed loads of fine ball powders can cause primers to back out...

Now you've discovered why the military crimps in primers. Because some contractor sold them a bunch of improperly seated primers and made up the excuse that the primers had backed out!

I've seen shotshell crimps open back up and bullets both back out and get pushed deeper, but I've never seen primers back out. Let me assure you, if they were found not fully seated, that's the way they were loaded.

Amen to what Stonecreek said.

Think about it. How is enough powder going to squeeze through the flash hole, with enough force to push the primer back out without pushing the bullet first and thereby relieving the pressure.
Not saying it couldn't happen. BUT HIGHLY IMPROBABLE.

muck

I believe that your friend has probably applied too much crimp on the cases. If he uses a "roll crimp" excessively, he'll create excess headspace. If he uses a "taper crimp" excessively, he will also created excessive headspace, due to the fact that the 45 ACP headspaces on the cartridge mouth. Another possibility could be over trimming the cases.