Listen to utah708. The .300 Win and 7mm Rem are "World" rounds that everyone makes ammo and brass for. From what I've read, you guys pay through the nose for you components as it is, why add availability issues to your troubles? Chances are, the action won't require any work either.
Either round can be loaded down some with one of the 4895s for smaller game, saving your barrel and shoulder a bit. Both rounds are accurate enough that they've been used for long-range match shooting and the .300 as a sniper round by the military.
