RE: Bear backup...
Well most here will tell you that you are wasting your time with a handgun with regarding bears but to me I would want my Dan Wesson 445 supermag with me just in case. I would just use heavy hard cast bullets at a good velosity and practice practice and practice some more. I would just feel better about having one with me rather than a shotgun leaning on the bank somewhere where I can't get to it.
Oh 454 is great for this as would the 480 ruger.
brian