Using a Remington 700 Action as a base for a benchrest rifle is not a good plan from the $$$ end of things.

If you want to build something for the long range bolt gun matches like we run in Pueblo, Byers and Raton it is a fine base.

PTG makes some aftermarket R700 bolts that you can use to tighten up the slop. However that slop gives dirt and grime a place to go and not lock up the rifle.

Most guys pick short action rifles to build on. For a 260, I would get a short action.