Former SE Alaska resident here, who is actually use to packing guns around in bear country day in and day out for self defense (not just some range rat, hunter, or someone who reads studies)!

Anything except the 4" .500, will be absolutely ludicrous! Even it, is a huge heavy chunk of steel, which makes it kind of slow to get into action. You will most likely be surprised, so lightning speed will be everything!

If I lived up there today, I would probably go with spray and a fast little Ruger Alaskan .454, backing up the very handy Marlin 1895SBL if I had the opportunity to have a long gun along. The only case where I might pack the X-frame, is if I absolutely could not have a long gun, and then only the 4" would be anywhere close to being practical.

Read and believe.... http://www.takdriver.com/showthread.php?t=723