DWM Commerical breechblock question

[ithacaartist]

This dent is puzzling, indeed. Looking at the cross-sectional drawings, this area of the breech block looks pretty beefy, despite the tapered relief hole/relief on the inside for the f.p. If the tip of the firing pin conforms to the shape of the hole, then the force of impact is transferred over a rather broad area. For a breech block to become pooched out around the hole for the striker's tip, it would be the corresponding area on the striker itself that would have to be the point of contact/impact--and the rest of this mating would need to not touch/hit. This is the only way I could see for significant material around the hole to be displaced/peened--by this area, alone, absorbing the bulk of the blow. And if the depression around this one's hole was caused by a punch, in an attempt to correct the former, where in heck does all the material go? How frequently is this deformation of the breech block face encountered?

[sheepherder]

Originally Posted by ithacaartist

This dent is puzzling, indeed.,,if the depression around this one's hole was caused by a punch...

How about if it was extensively dry fired, and the owner tried to remove the resulting 'ridge' by use of a round stone in a drill...or even a drill bit...

[ithacaartist]

Originally Posted by sheepherder

How about if it was extensively dry fired, and the owner tried to remove the resulting 'ridge' by use of a round stone in a drill...or even a drill bit...

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.