Regardless of caliber if you going to put a scope on the gun, you will be well served to put a good brake on it. the reason is that any rifle center fire rifle will recoil enough to pull the cross hair off the aiming point unless you have it mounted in a really heavy target stock. Since this is a hunting forum I will assume you have the gun mounted in a stock that you can carry on a hunt. The addition of a muzzle brake
will allow you to take the shot, see the bullet impact in the scope, make a correction if needed and take a follow up shot all with out taking your head off the gun and lossing sight of your game. compared your .300 winmag, my .308 is a pip-squeek in terms of power, and recoil and I run a well designed brake on it for the reason I expalned. So unless you have a full time spotter that will follow you accross hells half acre to spot your shots, put a good brake on your gun.