[.cheese.]

I took apart some old and poorly stored .38 +P ammo a few weeks ago. It was sitting out for about 20 years not stored in any acceptable way.

I removed the bullet and dumped the powder onto the lawn (since it makes for good fertilizer).

I decided today to get rid of the primers, so I went over to a local outdoor range just for safety (even though I knew that was overkill - but figured I might as well have some fun with my Savage Mark II rifle today) loaded the primed brass into a brand new duplicate 642, and just started to spend it.

I noticed quickly though that the primers were backing out and locking up the revolver.

Is that because there was no powder/bullet, or because the ammo was old, or could it be the revolver? I hadn't brought any .38 ammo with me (only a brick of .22s) as aside from the spent brass/primers, I was really only at the range to have fun with the .22. The range didn't sell ammo, so I couldn't test the 642 otherwise.

I'm back home now, I'm looking at the brass, and the primers are indeed pretty backed out.

What happened?

[zxcvbob]

That's what happens with you shoot just primers. The primer backs out because if pressure in the primer pocket, and there's no recoil to slam the case head back into the frame to reseat the primer.

[The Bushmaster]

zxcvbob has it nailed...

[Vern Humphrey]

Exactly right. Look into the primer pocket. Note that the area of the bottom of the pocket is much greater than the area of the flash hole. That means that the pressure against the primer is not much relieved by gas going down the flash hole.

This is why for some applications -- such as shooting primer-only wax bullet loads -- you should enlarge the flash hole with a drill.

[.cheese.]

That's what happens with you shoot just primers. The primer backs out because if pressure in the primer pocket, and there's no recoil to slam the case head back into the frame to reseat the primer.

DOH! That makes 100% sense.

Thanks guys. I should have used my noggin more. :)

I was concerned because I was thinking that there was less pressure than when there is a full load, but I forgot about the opposite reaction from the case. Darn physics and its laws.

[45ACPUSER]

That is why you have to increase the flash hole if you intent to shoot wax bullets, too!

[.cheese.]

I'll remember that for next time.