If you're going to be a serious long ranger, you need to practice. Practicing with a 300 RUM pushing 240s would be wayy too much recoil for most people and you'll probably end up with a muzzlebrake. If you're going to have a muzzlebrake anyway, you might decide to go with a 338.
I generally skip the big 30's. I shoot either a 7mm without a muzzlebrake or a 338 with, but I'll admit that a big 30 will do pretty much anything that can be done.
