I recently purchased a Remington 700 in 7 them mag but plan on buying a new barrel. It's the exact same action as a .300 win and I really had my heart set on that caliber. I was thinking of ordering a .300 win barrel and adjusting the head space. What's better as far as bc, bullet availability and power goes? I really want a gun that I can hit something with at long range and it not even know why hit it. A .300 having 1750 ft lbs of energy at 500 yards is pretty impressive IMO. Thanks in advance