Of the six Cape Buffalo I have killed, five were with my wildcat .505 bolt gun, which duplicates .500 NE ballistics, and one was with my .458 Krieghoff Teck O/U double rifle. My only reservation about the .458 is that it has too much penetration and a broadside shot at a buffalo may result in wounding the one behind him unintentionally. This reservatioin would apply equally to other .45 and .40 caliber rounds. The .50 caliber bullets pack more wallop and don't exit.

Three of the five taken with the .505 were one shot kills, as was the one with the .458, all frontal shots. The last one shot with the .505 was shot broadside running and absorbed a magazine load (four rounds) before coming to such a sudden halt that his nose plowed up the ground. One might have done the trick, but I just kept shooting until he hit the ground.

Having said that, the recoil generated by a .500 NE class rifle may be too much to allow the shooter to place his shots well, and placement is far more important than caliber. If I had a shoulder injury which prevented me from shooting the big stuff, I wouldn't hesitate to use a .375 H&H or even a 9.3X74R or 9.3X64, given the proper bullets (solids).