When a firing pin punctures the primer the gasses escaping from the cartridge case through the hole in the primer can and will gas cut the tip of the firing pin and the bushing. I've seen this on both pistols and revolvers. My Baretta 92 firing pin was severly gas cut when firing rem-umc 9mm factory loads. You could feel the divot in the tip of the firing pin. Rifles wether bolt action or otherwise also suffer firing pin damage from the same cause. Swedish 96 mauser shooting lapua match ammo (berdan primed) and a fellow shooters rem 700 in 223 had damage to the firing pin as well as a bunch of the cookies out of the primers inside the bolt. Took the firing pin out and rapped the bolt on a piece of wood and a bunch of cookies fell out. Frank