Primer blowout with BP?

[Dusty Tagalon]

Got back from range today, after cleaning gun, turned to brass. 10 of 25 no longer had primers. Possible causes?
My guess, insufficient compression or gap.
Thanks
Brian

[bear tooth billy]

Dusty, the primers were completely gone?  Can't see how that can happen.
I've had old guns back primers out a little bit, but then the cylinder won't
turn. The pressure of the round going off should slam the brass back and
hold the primer in. Can't believe the headspace could be so bad that the primer
could come completely out. My original 73 Winchester primers back out maybe
.020", but I've shot hundreds of rounds and it doesn't hurt anything.

                                 BTB

[Dusty Boddams]

Wore out brass?

[Dusty Tagalon]

New brass. Not enough head space to come out completely. Maybe loosened, & popped out when ejected. Also possibility of over penetration of firing pin. Went back to range with full case, & lesser charge with filler, not enough difference in the 2 rounds to use filler, no primer blowout.

[Books OToole]

I have a Hopkins & Allen that does that.  The firing pin bushing is gone. 
Shooting great but freezes up after each shot.

Books

[Dusty Tagalon]

Weird? Put 15 more rounds through it today, no primers fell out, but saw evidence of some blow back on recoil shield. Shot 10 rounds in a Uberti with no sign of blow back. Wondering if hitting primer high, off center may be deforming primer allowing some blow back.
Brian