A .44 mag, loaded heavy, is about 1,000 1,200 foot pounds of energy at the muzzle. 12-ga slug - 2,300 - 3,300. .308, which would be considered too light for a close quarters bear gun, is about 2,600 ft-lb at the muzzle, through a 24 inch barrel. Once again, a pistol is best thought of as a remote control hole punch. If you are trying for an instant stop on a bear, you are going to have to break through chest plate, hair, fat, inches of muscle, just to hit the heart. You saw how much time he had. I'd be lucky to hit bear in that scenario. Forget center mass, much less heart. With luck, you would hit him hard enough to sting him so he'd stay around and chew on you long enough for your buddies to shoot him from a safe distance. Your buddies would have a story to tell, but you probably wouldn't
The one time I was in Alaska,I saw more fly fishermen with a pump gun slung upside down and accessible than I did side arms.
I would like to know who won in that video.