Re: .280 for Moose..??
I recently shot a cow elk at just over 300 yards with my Remington 700 280 Mountain rifle, with a 160gr Partiton, moving 2825fps out of the 22" barrel.....spent the next day packing that cow and the one my dad shot a couple second earlier out of a pretty terrible valley.
I don't believe if I were to go on an expensive moose hunt the 280 would make the trip, not that I don't feel it is adequate. I just have a very nice 338 win mag and would likely buy something in the 375 caliber to go with me because I have been wanting a reason to buy one for a long time.
I don't think you would be under gunned with a 280 and a 160gr Partition, 160gr Accubond, or that new 168gr LR accubond, get them going in the 2800-2850FPS range.