Yes, I know the alloy. It's a very common one that hardens and tempers easily. Since the only part of a Mauser receiver that needs to be even partially hardened is the rear of the receiver ring where the bolt lugs engage, it's not particularly difficult to do. Even if those lugs aren't perfect, how many thousands of rounds being fired would it take to make a measurable difference in headspace? Annealing and re-hardening an 03 receiver that's harder than woodpecker lips all over is a different kettle of fish entirely, and is something that I won't attempt.
Lol, how many rounds does it take to get to the tootsie roll center...... Lol
Answer is, not near as many as you think. Tom Burgess once showed me what appeared to be an unissued Argentine 1909 that had setback. Presumably the only round(s) through it were the proof rounds.
So, if your Mauser receiver is soft, how you gonna bring it up to snuff?
I'd be really interested in this very common alloy that hardens easily, especially since it is well known that military Mausers were made of a low carbon allow and that they were case hardened. You don't just toss a Mauser receiver in an oven and it magically hardens. You need to introduce carbon into the surface metal to get it to harden.
