Aldo & Hugh
Thanks for the idea. So perhaps the expanding primer is causing or has caused the indent in the breech face?

The ammo I was shooting is factory loaded Fiocchi FMJ. I understand its loaded a little hot because it is also used for those pesky SIGs, Browning HI Powers and Benellis that have barrels in 30 luger.
I have not shoot this gun much at all. Maybe 50 rounds since I have owned it.I wonder if a PO put some hot reloads thru it?
Verrrrrrry interesting.

Bob