Great Posts guys. I think Renaisance prolly came closest to the explanation that makes sense to me.
Other notes: it's a 625 in .45acp. NOT a .45 long colt. No worries there.
Bullets mike to .452. Cast lead only is all I fire in this gun.
I use a normal .45acp bullet - no crimp groove. Experiments with "crimp grooved" bullets have been less than stellar. I've gone back to normal bullets.
Detonation on the bullets? No worries there. 3.6 grains of Clays is the lowest I load. Cases come out clean, no abnormal soot.
Anyways, I'll drop crimp to minimum to see what happens.
Thanks for the advice.
"Remember, Eagles may soar but Weasels don't get sucked into jet engines!"