I would follow the suggestions above for finding the "most powerful" cartridge. A heavy bullet traveling at a good velocity, with lots of practice. It don't matter how powerful the gun is if you can't hit a vital spot with it (where's a good spot for a "one stop shot" on a charging bear?)
But, I have some thoughts on traveling in bear country. I'm not an expert, but I've read that bear attacks often occur as an "ambush" or happen within seconds of a "meeting". Will you be walking with your gun in hand, cocked and ready? I've read of Cougar attacks where the victim never heard or saw the attack coming, just walking/jogging along a trail and waking up in a hospital. There are black bear and cougar in my area up in the hills from town and I've thought about this subject occasionally. I seriously doubt if I could draw and fire my SBH in 44 Mag. fast enough to save my old butt from a running/attacking bear, so I just make a lot of noise when I think there may be someone in the area that would do me harm...
There were no bears in Compton where I grew up (just dogs, cats and rats), and no game to speak of in L.A. County, so at best I'm a rookie woodsman. Most of my info comes from locals, long time residents/hunters in my area, and my common sense...