260 is made from the 308 case (6.5x51) or if you wish 6.5-308. Bolt face diameter is the same for 308 and 30-06. So................anything made from the 308 or 30-06 case will fit the bolt face. The main difference is long or short action.
If you use a large ring mauser action, you will put more than $600 into it. Unless you get one that has already been properly sporterized. You can find some of those in gun and pawn shops.
Most of my rifles are built off of the large ring mauser. Even though I do the work myself, parts for the conversion can be costly. Orbendorf follower, timmeny trigger, good quality barrel, reamer purchace or rental, stock, bolt handle, floor plate release, scope mounts, etc. And once everything is done, all of it has to be polished and blued.
The easiest to change over would be the savage.
No such thing as a stupid question. What is stupid is not asking it.