That would be an extremely large Caribou.
Weights of adult bulls average 350 – 400 lbs (159 – 182 kg). Mature females average 175 – 225 lbs (80 – 120 kg). The dressed weight of a 400-lb (181-kg) caribou is about 240 (109 kg) lbs. This equates to about 100 lbs (45 kg) of meat.
Caribou Hunting in Alaska
http://www.adfg.alaska.gov/index.cfm?adfg=caribouhunting.main
It does seem rather light for the bear. At least it is less than I want to carry for black bear.
A friend who’s an Alaska guide uses .338 Win mag or .375 H&H for bear protection. I believe there is a minimum round for licensed guides.
Like dealing with a bad guy, ANY gun is better than none.