Pistol primers and breech block damage?

[JKR]

I think you would have to fire an awful lot of pistol primers to cause firing pin hole damage. I know a number of the big dogs that shoot nothing but rp pistol primers, and there are some that use various pistol primers , but they have modified the capping tool so that it will take a strip of paper and seat a thin wad under the pistol primer to "headspace" it .

Yes. It’s hard for me to wrap my head around the idea that the primer slamming back .006” or so would have enough force to dent a steel block. And yet there’s a primer size, circular dent around the firing pin hole.
Jim