I'd go with a 300 Mag of just about any flavor. Win Mag, Wby Mag, or H&H. I personally carried the H&H 300 and it did everything I asked of it. Load some fine 180 or 200 grain of proper construction and have at it. I shot the North Fork 200's and couldn't ask for better performance.

I would have felt better carrying a 375 when we were rubbing elbows with elephants and buffalo, though.