Alaska country is tough, rugged and typically quite wet. And the largest bears are seldom far from salt water.
Guides in such rugged country typically do not allow hunters to carry rounds chambered due to the chance of the hunter tripping or falling. Which means hunters with double rifles need to carry empty and then load on the final stalk.
This really is not much of a handicap as I carried my 450/400 double that way for a few years. But I much preferred carrying a bolt rifle