And an action wrench. The pins locate the recoil lug when you torque it up.
I have 5 barrels that I can swap between two Stolle actions - unscrew old barrel, clean threads well, apply anti-sieze and lube, screw on the new one. Each barrel will shoot to a different POI, but that is very repeatable.
With your boltface you could go 6BR through 30-06 or 284 class (single-shot on those that won't fit/feed). As noted above, 260 is 308 necked down and would be simple barrel swap....
Cheers,
Bill