I don't go where big bears roam on purpose ever since I listened to the audio of the grizzly man and his girlfriend being attacked and eaten.... Good luck. I vote 10mm & take the Glock because they work when it counts
This is what I took on my last hiking trip to Colorado. I studied it, read all the reviews, pro and con then made a choice. Glad I didn’t need it this trip but felt good knowing it was by my side! I carried a S&W M&P 10mm. DANGEROUS GAME 10MM AUTO - Mono-Metal
Seriously, it would depend on the firearms you have. If a strong 45lc, you can load it to near 44 mag loads. If not I would go with the 10mm even if it is in a pussy Glock.
I was a fan of the Super RedHawk in .44 mag, carrying it in a chest rig when in bear country which seems to be a lot these last few years.
The last trip to Yellowstone and Glacier NP changed my mind after some long hikes in the backwoods of both.
The gun is heavy, recovery from recoil to take follow up shots all made the difference in changing the preference to 10mm.
Since I competed in USPSA with an S&W, I was excited to see S&W come out with the series 2, so one was purchased this spring.
There has been several hundred reload range rounds put through it now without a hiccup.
I don’t have large hands so the availability of adjustable back straps was appealing to me as well.
Looked through all the available dangerous game cartridge makers, deciding on the Underwood 200 grain solids for Grizzly country and 140 grain penetrators for black bear country.
Pretty snappy loads.
For a holster, since it will be OC, decided on a leather Bianchi with level 1 retention so it won’t come out in a fall.
Off the top of my head, cant remember if there are bigger bears up there.
A lot depends on your loads in the firearms you listed.
Since 10mm and 357 magnum can be similar in power (splitting hairs would mean loading and cronographing from the tools you listed.
A equal grain weight 357 has better sectional density than the 10mm, therefore the a apples to apples boolit of equal power, the 357 will drill its hole deeper!
If the bears are bigger than black bears, take the 45 colt with some stout loads safe for your Ruger!
Edit in reguards to the guy in the video shooting the bear target.
I (think I) would have my pistola out as soon as I saw the bear, and would begin firing as soon as the bastard charged!
The more bullets the better. Once I was turkey hunting and came around one side of a evergreen and a mt. lion came around the other side. I think I shot five rounds of 12 gauge and six rounds of 357 in about 2.5 seconds. hit it with one round at a distance of less than ten feet.