I lived and hunted big game in COL, N.M. and Utah;
I have owned almost all calibers, except 300 WIN mag, which my buddy had, and my favorite for all was my 7MM REM. MAG.
I had a 22-250, a .270 win, and a 7MM REM MAG.
You can grab either of these guns, and shoot them all the same, as holdover goes, they are so close to each other;
I killed more mulies and Elk with my 7mm than my buddy did with his 300 win mag cause he didnt like shooting it; not that the 7MM was a peach to shoot;
AS for over all kills?
.270 WIN by far, then my .243 WIN (my 243 outshot his 300)