Personally, I feel the 458 is too restrictive in its use. A 375 H&H is more versatile as an all around cartridge, but really is minimum I'd suggest for buffalo. Maybe you should look at either the 404 Jefferies, or either the 416 in either Remington, Rigby, or Taylor. I prefer the Rigby as Ruger supplies it in their bolt action configuration. Just a personal choice.