My Tikka T3 in 260 Rem. shoots best at 2850 fps with 120 BTs and 2710fps with 143ELDX. This is with a 22.6 inch factory barrel. Not the hottest load, but these are just under 1/2 MOA for 3 shots.
Starting over, I would go with 6.5 CM because of the selection of good ammo, the mag limitations of most 260, and the cool name.
Good thing with the Tikka is a simple bolt stop mod and a $40 mag replacement allows you to load bullets up to 3.4 inches. (Still missing the cool name.)
