I would use my White rifle with a 495 grain .451 volunteer bullet(hand cast). I would take my .54 Hawken as a spare.
The .451 works great on moose, should work great on elk. Black bear on the other hand don't take a huge ball or bullet to kill them. Boone killed hundreds with a 39-40 cal, shot placement,shot placement and shot placement. They are thin skinned and a lung shot(double) is a sure thing but they will run 50-100 yards before they expire. I've shot a couple in the head and a couple in the neck and they were DRT(dead right there), but the majority were lung shots.
Nit Wit