From my armchair, but I’ve been there...
I think they were undergunned. At least 10mm, even that is slightly light.
I used to know this bartender up in Homer Alaska. He’d been around there quite a while. He used to tell me things like... if you want to hunt Moose plant a rose bush, they love roses. His hunting weapon of choice was a .458 Winchester magnum. His sidearm was the biggest available at the time, a .44 mag S&W 29.
He said when hunting the browns, it took 2 shots from the 458, a hip shot to break the hip and set it on its arse... and as it raises up its upper body with paws in the air, the 2nd shot was to the chest to blow its heart to pieces.
Of course when a pissed off big bear charges you suddenly... it’s all moot. Whatever happened to the 500 S&W as a carry? I thought that was all the rage for Big Bear defense.
Caliber does matter but I recall the Florida cop killing an elephant in Musth that went berserk and he dumped 20+ rounds of 9mm from his Glock into the head of that thing and put it down.
I don’t know what I would use, probably a 3in 12 gauge for starters. Spray is dependent on wind direction. Hand gun? Something I can bring back to target for quick and accurate followup shots. Type of bullet? Hard & Solid for head shots. And if a bear is charging you that headshot might be the only option.
In other news: the world record bear was taken by a 12 year old girl with a .22!