There is no "best" caliber or cartridge for any animal anywhere in the world. With an almost unlimited selection of calibers/cartridges and even more selections of bullets available, some choices may be better than others, but it really should come down to which caliber/cartridge/rifle combination one shoots best and is more confident in -- because it ultimately comes down mainly to shot placement. While some outfitters may require a minimum caliber for some game, a hunter should educate him/her-self to have a rifle in a manageable caliber with a barrel twist compatible for a specific bullet type that is appropriate for a particular game at a reasonable distance. When a hunter is confident enough in his gear to place a shot precisely, and has the right combination of components, the caliber or cartridge used is less important than these other factors. So choose a rifle that you can shoot well, and make sure the components (cartridge, barrel twist, bullet) are appropriate for that animal and distance of shot and any of several calibers should work equally well.

Used a 338 on mine last year, left an entry hole in the chest the size of a nickel and dropped him in his tracks at 180 yards. Your fine with it.

Are they anatomically like lots of African species, with guts "shoved forward" so that a "behind the shoulder" shot is pretty much a gut shot? Lots of the animals I whacked over there were a low shoulder shot for heart and lungs.

Yeah I'm gonna bump that thread too

Yes.