My two cents. When I was first starting to look at an Elk hunt, all the outfitters in Montana told me I needed a 300WinMag, so I bought one (it's still new in box). I called a New Mexico outfitter and he said my 308Win was more than enough, and he was right, dead elk. In fact, it also killed without a problem a large Red Stag in Croatia too. Don't buy into the must "have" caliber. The only must have is really a 375 in Africa, in case you run into something you were not expecting and want to make sure you have a legal caliber.