Hello Gents
Got some more pics of my gun.
1 pic is back of frame-no sign of the toggle hitting hard?
2-pic of extractor and firing pin in breech block
3-pic of firing pin tip
Thanks again for all the help.:)
You folks are the best!
Bob

In photo #2, it really shows the breechface depression.....unless the photo is tricking my eyes.

It all looks smooth and regular, although a slightly different color than the rest of the flat surface there. I'm doubting a rotatory stone or burr..maybe a drill bit sharpened at a verrrrry shallow angle (which, itself, would be hard to center?), but a long time ago because the area does show some "age" in the pics. The base of the cone of the f.p.'s tip looks a little gnarly in the pics, how much dry firing would be necessary to achieve this?

Perhaps an experiment is in order. Pounding a sacrificial firing pin repeatedly into a sacrificial breech block would answer a lot of questions. As I understood it up until now, the damage risked by dry-firing was that the tip of the f.P. would work harden and become more brittle--enough to snap the tip off with the shock and momentum involved in the dry-fire. I'm still skeptical that a cone pounded into a cone would produce the mushrooming/upsetting around the hole.

I'm my opinion it's very unlikely that an expanding primer can cause the indent in the breech face.
IMHO

Sergio

Breach Deformation
 

I have a hard time visualizing dry firing causing this deformation. I would think dry firing would have caused the deformation to be convex not concave.

Aldo35