I am not the best to answer your question, but I"ll get it started. In my Savage 10's, anything slightly less than 3inches coal will feed through my action. My longest load measures 2.9457" coal, and they cycle and eject just fine. "I" don't feel that a 260Rem needs a long action, no matter what the throat deminions.(jMHO :) .

That being said, all my actions are set up for single load, including my hunting rifles. I don't invest all of this time and money into assembling the rifle I want and reloading "to miss". "One shot, one kill" :-)).

The other thing is, for hunting accuracy, you don't have to use the load you mentioned, and you don't have to chase the lands. I have a hunting rifle, that when shooting it's most accurate load, jumps .160" to the lands, and I can shoot that rifle less than MOA out to 300yds.

Good Luck/Good Shooting.....Jim :-))