My thought has always been bullet weight vs caliber. If your going to shoot .308 projectiles in the 150-180 class then the 30-06 is just great. If your going to maximize the potential of the 180-230 class bullets then the 300WM and up calibers will do what your seeking. After saying that I'm pushing a 165gr bullet out of my 300 WM at 3260 fps with sub moa accuracy and at 500yds the ft lbs is pretty impressive. But what is the end result of what your trying to do with the caliber?