Lol. My worst was also a mauser, although a spanish one.
Bought a 7x57, paid decent money.
And it absolutely will not feed. Not like it's unreliable. It literally will not feed a single round.
I can normally fix stuff.
Made a Mosin feed 375 H&H. 500 Jeffery in a Savage 110. 500 S&W in a Siamese Mauser. None of these took more than minimal effort.
But getting that mauser to feed the original cartridge it was chambered for, from the factory?
Absolutely not.
Right now, that rifle is being used to hold up a corner of a broken shelf lol. Eventually, I'll make some bottom metal to take a detachable single stack mag from Wyatt's or AICS. And probably rechamber for something modern and suppressor friendly, just out of spite.