Pound for pound you can load a heavier bullet with more speed than you can with a 300 win mag than a 7mm mag. Okay now if you only shoot 200yds. period then I would suggest avoiding the recoil and shoot a 30-06 with 220gr bullets and not worry about the rest of the hype.

I shoot a 300win mag but I shoot 165gr bullets and I shoot them for tragectory. When it comes to killing something the shot placement will over come the bullet size no matter what. The difference is aiming inside the body at 400yds plus and aiming outside the body. Some special men outthere can do it with any gun they pick up.