Punctured Primer

[mrerick]

I've been assuming a 9mm Luger pistol, which your 41 byf should be. All 9mm Luger headspaces on the mouth of the cartridge. The stepped chamber was a DWM innovation to further seal the chamber during firing. It would be good to photograph how far the cartridges are protruding from the barrel breech. Be careful to remove the toggle train if you do this with a live cartridge, and treat it as a loaded gun.

Thanks to the fluted firing pin that should be in this pistol, you probably didn't have breech block damage.

There is definitely something wrong if you are piercing this high a percentage of primers.

If this is not an all matching gun, be aware that the wrong size parts may have been installed by someone (there were two breech / receiver lengths).

Follow Jerry's advice, and get a good look at things first...

Marc