Hunt with what you want, but I'd not hunt elk with anything less than a .30 cal of some sort... but that's just me. And I'm qualified to make that statement. because I have killed elk with .243 and .270 and they were dead in the freezer. But I like a bigger bullet because if you hunt enough sheet will happen. But I'd still go with a bit heavier round/larger caliber. Good luck, and shoot straight whatever your choice ends up being.
