A relieved firing pin allows expansion gases to escape in the event of a pierced cartridge primer. If the gas can't escape in this situation, it can get really ugly.

You mean if the firing pin hits so hard that it actually punches straight through the primer cap instead of just dimpling it?

Does that happen often? I can't say I've ever seen that happen with my glock or sig. Is this something that Lugers are known to occasionally do?

Yes, it may punch through a defective primer or the primer may blow out the side if it was crimped or improperly seated. A fairly rare occurrence but can be spectacular and destructive when it happens. It has been known to blow out extractors or a chunk of the bolt face rim.

A relieved firing pin has grooves cut in the forward portion of the pin to allow the gasses to vent back through the firing pin hole. I would bet Tom Heller (Lugerdoc) has a whole Mason jar full of them (and he will sell them!)

Thanks for this thread guys, I have every intention of shooting my newly aquired artillery piece, it's just too attractive to leave lying around. In the few rounds I have shot I did notice that the primer seemed to be struck very hard and deep, I'd be sick if the gun was ruined. So I'd like to know what else should need replacing prior to shooting?? Thanks again for such an informative forum.

So I'd like to know what else should need replacing prior to shooting??

Everything that might break and has an irreplaceable number..Including the grips.

Jerry Burney

There is also the slotted thingie which locks the assembly into the bolt. It takes 1/4 turn to snap the thingie in and sometimes it sticks at slightly more or less than 90 degrees.
Agree to Hoppe and Qtip inside-front of the bolt, clean firing pin. The sear and disconnect I haven't had the cajones to disassemble yet.