View Full Version : primers backing out?

04-10-2010, 09:24 PM
I got a Hot Deal (tm) the other day: nearly 200# of mostly .38 Special brass. It looks pretty good at first glance, some is deprimed and a fair number is actually primed but not shot. Wondering if the primers were any good, I stuck 4 in a revolver and fired them. The first 2 went "Bang!" just as they should have, but the cylinder was kinda stuck. Pushed it open and found both primers backed out a bit. Removed those 2 cartridges and fired the other 2. Those primers didn't back out. No powder was involved, of course.

Any ideas?

I'm figuring on cleaning the stuff, packaging, then selling it, as I load only .357 brass, even for light loads.

FWIW: that much brass is 4, 5-gallon buckets, each about 3/4 full. It's a LOT of .38 Special brass!

04-10-2010, 10:55 PM
This is not unusual in a revolver. What happens when a "loaded" round is fired is that the cartridge acturally moves back in the cylinder and "reseats" the primer.

When you fire a primed case only there is a pressure build up as the gas tries to go thru the little primer hole all at once and it backs the primer out and they drag on the recoil shield of the revolver. The reason it happened with two and not the other two may be that the flash hole in the brass was a bit bigger or the hole the primer fits into was a smidge smaller causing more resistance and holding the primer in place or a different brand of primer...

Hope this helps..


04-10-2010, 11:25 PM
Don has it perzakly right. :D


04-11-2010, 11:27 AM
Thanks, fellas!

I thought I had read someplace that this situation was "normal", but I couldn't remember the details.

04-18-2010, 02:33 AM
You could take one of the problem cases and see how much force is needed to press a new primer in. If you have a feel for that, you should be able to readily tell if the pockets are loose.

Based on the other posts, you are probably just fine, but this would confirm for you that everything's ok with the cases.

04-19-2010, 06:56 PM
The primer moves back in *all* cartridges, not just revolvers.. depending on the chamber dimensions and the cartridge.

No way a press fit primer is gonna take thousands of PSI and not move.

But all are correct, the case is then pushed against the bolt face (or whatever its called in a pistol/revolver) and quickly reseats/seals it back up.

reprime the case and if it feel light, toss it. They are free to you and not worth damaging your gun/hand if they are out of spec.

04-19-2010, 08:28 PM
I'll check a couple to be sure they're OK.

As far as loose primers go, I had one actually fall out of one of my well-used .45ACP cases. Was shooting a match and had a "misfire". Ejected the "bad" round and continued. Picked it up and found no primer, then found the primer in the magazine. Just for the heckuvit, I tried pushing it back into the case. Successfully! Dunno how many other cases I have that have that badly worn primer pockets, but it's not from high pressure, as my loads are just heavy enough to function the gun reliably.

04-19-2010, 11:41 PM
... but it's not from high pressure, as my loads are just heavy enough to function the gun reliably.

High pressure is relative. Your still probably getting in excess of 15,000 PSI. That will cause stretching with enough reloads.