Breech Block question
 

Just picked up a 1917/1920 Erfurt P08, noticed that the breech block has a chip on the right front top, and a similar size crack on the opposite side. I think I might have found a replacement block but have some questions before I send the $$'s. Any help from the experts on this board would be appreciated!

1- Since the each Luger is in a way a 'one-of-a-kind', are breech blocks interchangeable? Are any modifications needed?

2- Haven't completely disassembled the gun as yet, but does the breech block have a serial number that matches the rest of the gun? (the number '21' stamped is on everything else).

Most breech blocks will provide a drop-in fit, although your results may vary. For a breech block, not much work will be required to fit it.
Yes, the breechblock is numbered to the gun.

This is typical of firing too-hot load/ammunition in a Luger. The shell expands excessively and blows the extractor upwards, breaking off the two side 'wings'. If it was a catastrophic failure, it may have blown the magazine apart as well. Check your magazine well for gouges or scratches... :p

Good info on both that cause and the fix. Any feelings about using repro block if I can't find OE

Don't use Numrich repro parts. Get a breech block from Lugerdoc, or failing that, Sarco. I had to wait ~6 months, but Sarco came through with a used 'original' for me...

99% of these I've seen or heard of that chip like this are Erfurts...dunno why...have one myself

Probably a 'dumb' question, but can you fire it with the chips in the BB ?

as long as the chips are small and confined to the area of the extractor slot, shouldn't be a problem...I'd keep a close eye to see that cracks dont appear or migrate to the bolt face