Ammo question.
 

I have a gun that has been fully gone through by Ron (41 Mauser-miss mached). Problem is it keeps bending or breaking the firing pin retainer. Just got it back from Ron again, shot it this morning. 50 rounds winchester 115, no problems. First shot with Fiochi 123 it broke the retainer again. Looked at the back of the cartrige and it looke like it had a hole drilled through it. As I said thes gun was rebuilt with all new springs. This is the fouth time it has happend, and Ron has been very helpful al the way through.
I guess my question is, is the bigger round a problem for these guns? Anybody have any other thoughts?
Thanks:confused:

Sounds like the firing pin is protruding to deeply, piercing the primer, causing gas blowby and a broken firing pin retainer as the result.

Check the inside of your gun's bolt to see if anybody bored out metal and also, if this has been the same firing pin all along, perhaps it is out of spec.