Guy up here killed a bear by shoving his 1911 down it's throat.
(sometimes the bear gets you, sometimes you get the bear.)
Not sure about what it does or will not do in regards to glocks and shooting cast bullets. Glock just specifically states its a no no.
If you got brownies a solid bullet would be a must out of a pocket rocket in my opinion. It will be about penetration if you want to get something done. No handgun fired bullets gonna knock a 1000lb bruin on its ass. If it does not run due to being hit or dies from being hit its gonna do what a bear will do. If you are able to push some grey matter in it might do the trick.
I would not feel well equiped to handle a bear with a glock in any caliber. If I was backpacking in the woods and had plans to spend a good amount of time doing so and with a limited budget I would invest $200-300 in a remington 870 and load it with as many rifled slugs as it would hold. I would get a fiber front sight again its cheap and can be installed by most anyone.
If you wanted to trim the weapon a bit you can get riot guns from most any dealer that have shorter barrels and moss has a shotty they sell with a pistol grip for about the same money. Its about the best advice I can give you. Most people that have shot in their life have shot shotguns and its pretty easy to handle and be decent with even under stress.
Big bore revolvers weigh about as much as a shotgun in large calibers and are extremely expensive in most cases and very difficult to be good with for most people. You go past .44 mag with them you will be going into very powerful handguns that are going to be difficult to manage under stress and nothing says stress like being charged by a brownie. At least it would be stressful(shit my pants) for me.
Edited to add: They also sell the moss and remi shotguns in a stainless version for weather and environments just like where you are living.
I have a G29 and have shot the Buffalo Bore before. It is hot! It is also $$$$. Only go through a mag or two to get the feel of it and save the rest for hiking. For practice I think that I run the Winchester (white box?) or Corbon through. I've run the cheap Blazer rounds but I don't think I would use that for carry ammo.
I also have a G30 and can use the same holsters and ammo pouches.