What are you going to do with the rifle? I hope it will become a classic custom rifle with a nice octagonal barrel, a fine stick of valnut and have nice metal work
I guess your rifle is a 8x57 I. Soo to get a wider range of bullets you have to get a barrel with 323 bore. I had a commercial mauser obendorf with double square bridges made before WW:1. The old mausers are very nice. Camber it in a classic cartridge don't do anything stupid with it, like trying to hardcrome the action or fit a stainless barrel to the nice blue action If this happends, then Atkinson and the "mauser maffia" will correct you in a more physical way Hire a competent gunsmith and no clown work, please. The action is worth a better end than that.