I have a 264 Win Mag Sense to and am developing loads for accuracy. As the 264 has ample case capacity and I generally like to have 90%+ fill, this would favor the slower powders. That said, I've tried some RL33 and noticed the heavy barrel is not after 1 firing on a cold barrel. Closely similar velocities with faster powders seem to put less heat in the barrel.
Q's: Assuming I find an accurate load with faster powders (IMR4350 is not bad), will the barrel life be better off with the faster powders or slower powder? I had thought that peak temp would be lower and favor the slow powder, but I'm having second thoughts on that theory.
