PS One of the popular cartridges for cape buffalo in the "old days" used to be the .318 Westley Richards with 250 gr projectiles. Basically the original .338/06 with a .330 calibre.

Since then the .375 has become the minimum in most countries in more recent times.

What will kill cape buff will kill water buffalo of course, but a wb is a bigger animal perhaps a bit harder to put down.