I agree w/the previous posts. Don't get caught up in the "bigger is better" mentality unless you know that is what you really need/can handle. That 300 Winchester Magnum will have much greater recoil over the more standard calibers mentioned. Very important to recoil w/this caliber is the eye relief w/this scope. What amount of eye relief does the scope provide, especially at max power? Until you shoot the gun w/whatever loads you would intend to hunt with, ie, discover the amount of recoil, you don't really know completely the eye relief is adequate for you.(sarcasm: Scope eye feels really good) The previous non magnum calibers mentioned are very capable and the most practical place to start.