You don't need some shotgun that's been built for tactical operations, that's just ludicrous. If you're that worried about bears, take a short barreled hunting rifle in 30-06 or bigger that you can shoot well, slung over your shoulder.
I carry my Marlin 1895 XLR in 45-70 with a ghost ring peep and front firesight, loaded with Garrett 420gr +p Hammerheads. I also use it for hunting bear and moose.
