Not a side arm: but a Remington 870 Wingmaster with a smooth slug barrel, parkerized with synthetic stock. If I seriously think i may need to stop a bear, I will seriously try to stop it.

Maybe, unless you're the poor schmuck who stumbles on a half-blind, very unhappy bear down the trail.

JMHO - but a very bad idea.

I think you missed the point

I didn't. You're really suggesting that one person carry a weapon intended to maim the charging bear so that the other person can kill it? I would not want to be holding a 10-gauge with birdshot when I could've had a rifle instead. You're obviously willing to gamble on more than I am.

Not only will the poor schmuck stumble on a half-blinded, very unhappy bear, but they'll have to be the one to report the two bodies up the trail.

This kind of stuff might be why it DOES make sense for states to require nonresidents to have a guide.

i am not sure what you hope to achieve with a back up, once you have emptied your primary weapon i woundnt think you would have much time to reach for your backup but since i am an archer and my primary choice only gives me one chance i do carry a 454 just in case i get lucky enough to pull it and make a shot or two before i am bear bait

Have you considered something like a semi auto pistol in say 10mm with a high cap mag?

All one really needs in a bear charge is a .22 revolver.....not for the bear....for your buddy.....you shoot him in the foot and take off.....you don't have to outrun the bear...just outrun your buddy

Yep! That,s another good one .... You don't have to be the fastest, just faster than the slowest!

In all seriousness, in bear country with a documented concern about bear attacks, I'd be armed with the largest, most potent rifle round i could handle well. If the legal amount of shots didn't stop a bear that I was trying hard to avoid I doubt that dropping the rifle and reaching for a handgun would be a lifesaver.