I have a Kimber Target II in 10mm and it is my go to hiking gun since it is lighter than any of my wheel guns, of course where I live there are no bears. I also reload for the 10mm since Manufactures have decided to down load the mighty ten to .40S&W levels. I can load a 200gr Hornady XTP over a stiff load of Blue Dot right at 1250fps. It's just a hair under max load and works perfect for me. I have also recently cast up some 200gr hard cast bullets for it and have them clocking along at 1200fps out of my Kimber. I could push them a little harder but they shoot fine at this velocity and when fired into wet phone books they penetrate deeply.
When I had to work up in WA state I took my 10mm with me and wore it while hiking up in the hills just in case I ran face to face with a Mt Lion or Black Bear.
I think the cartridge would be a minimum for protection from large bears and that would be if I were using the hardcast bullets.
With the Glock you can load 15+1 but you are limited to jacketed bullets unless you buy a drop in aftermarket barrel. Then you can shoot cast bullets out of them. You can also get heavy cast loaded bullets from Double Tap that are pushing a 200gr bullet at 1300fps and have a nice wide meplate to do the most damage to the beast that it strikes.