Pistol primers and breech block damage?

[JKR]

Jim,

I have some damaged breach blocks with primer dents as well gas cuts around the Shiloh blocks I shoot the most as well as the Stevens breach block. I don't pull the Stevens block to often so it has more damage than the Sharps before I caught it.
I think the dents are not only from pistol primers but also from the rifle primers. My .50 I shot more than the rest I only have used LR primers and it is dented also.
But these two blocks in the photo got gas cuts from using pistol primers and cutting paper seating the primers. The paper is under the primer not under the powder. I cut the paper seating the primers to keep them at a proper hight.

Kurt,
The Sharps block looks like my Shiloh except for the gas cutting. Is that from gas leaking around the primer?
A friend has told me he’s had this peening happen in three different rifles, two of which never saw a pistol primer. It got to the point of impairing the firing pin travel. He had hardened discs installed to cure the problem. I can’t say my issue was caused by pistol primers but I’m giving up on any use of them.
Don,
You may be right about the firing pin protrusion. I made up a spare firing pin this morning, so now I have one I can experiment with.
Jim