Hi Greg,
I've shot a few moose in Alaska and one in Minnesota. You can't beat a shot throught the center of the lungs. Here's a good drawing of the vitals on a moose, or elk, caribou or deer for that matter:
http://www.state.ak.us/local/akpages/FISH.GAME/
wildlife/geninfo/hunti...
You have plenty of gun. Best of luck!
Buck Alaska Hunting Adventure: 700 Miles Alone by Backpack and Raft