Thanks for the input. I have a .308 RL, and like it for hunting though the barrel does heat up quickly as you mentioned. The more powder you burn, and the bigger the hole is I suppose accelerate that. I'm looking at a .223 as a walking woods gun for coyotes, etc. I want to shoot the 55-64 grain bullets and like the idea of the 9" twist. For practice I would shoot cast bullets with small powder charges.