First things first. In the area of the rear sight ensure that there isn't a raised ring in the barrel. This is indicative of the 60's model that would have a different bolt face and would be prohibitive for current barrel changing efforts.
That said, early on, Savage had their long action chassis (the 110's) that they milled out a short action mag box for and went from there. Some actions they actually made shorter, with a shorter screw spacing but still called the 110. Both of these guns can accept any other short action round and remain in a repeater mode.
You're 260 will work in that regard since the parent case is the same. 308, 7-08, 358, etc. You could do 257 Bob, and 7x57, but some may quip that the mag box will not allow you to maximize OAL if you reload. You may have feed issues if you decide to do a 222 or 223 - and you would need to change the bolt head.