When I began hunting Africa in the 1970s, if you talked to any of the old-time PHs about the best dangerous-game cartridges around, there were two that would almost certainly be on the list. One was the .470 Nitro Express, and the other was the .416 Rigby. The former was strictly a double-rifle proposition, but the .416 was for bolt-actions. Brought out by John Rigby in 1911, it is a startlingly modern case (albeit a very big one) with very little body taper and a sharp shoulder. It fires a 400-grain bullet at 2,400 fps, which gives it considerably more authority than the .375 H&H, and a lot less recoil than the .45-and-bigger rounds. Indeed, this is the great strength of all the .40s.