The weatherby is what 100 fps faster with max loads something like that. IF the bullet is put in the right place from a 300 win mag,300 WBY, 300 H&H or any other 300 with similar ballistics the animal is not gonna be able to tell the difference.

Comparing a 300 win mag to a 300 WBY is kinda like comparing a 243 to a 6mm, what one can do the other one can do. Just shoot which ever one you like the best.

I would think more in terms of are you gonna reload, shoot factory loads. If you reload it doesn't matter. If you are gonna shoot factory loads the 300 win mag IMO is the best choice.