You are out there with a high powered rifle, probably .30-06 or bigger. A bear charges you. You empty all four or five rounds out of the rifle into him without stopping mr. bear. By now he is on top of you, and you think you are going to pull the revolver out and start shooting? You will be better off being very sure of your aim with the long arm!
When I came to Alaska in 1966 I bought a .44 magnum. The old timers all said to save the last cartridge for myself in the case of a bear attack! We had a presentation at the University by one of the Fish & Game people and he was asked about carrying a handgun. His response was that, what they had seen, the people with pistols tended to push the personal space of the bears and got into trouble more.
Then remember also that the .44 magnum is ballistically equivalent to the .30-30. Grizzlies have been killed with .30-30, but most people wouldn't carry one for bear protection. Now I know, lots of bears have been killed with the .44 in a self defense situation. However, a lot of bears have only been wounded which then makes them even more dangerous. When I was at Cape Yakataga working, some guy saw me walking the beach on my time off. He was staying in one of the mining cabins there, and called me to ask if I could help him look for a bear which he had shot with his pistol. It had walked by the cabin the night before and he wanted to chase it off so he shot it. We were working on a new water line to the White Alice site, and this meant we had to have a rifleman on the job to make sure we weren't attacked by a wounded bear!
Later on I worked on a survey crew with a guy (his last name escapes me after almost 40 years) who had been backpacking off the Denali Highway with a friend when they were charged by a grizzly. Now Roger had been a major in Special Forces in Vietnam and had enough fruit salad on his uniform to feed an army; he was cool under fire. He carried a .44 magnum, loaded with five rounds and the hammer on the empty chamber. He emptied all five into the bear, then was able to reload three rounds while the bear was killing his friend. The bear then came at him and he got all three of those rounds into it before it finally fell dead a foot from his toes. Fish & Game found all eight rounds were within 8" of each other in the bear's chest and any one of them should have killed it, except it didn't know it was dead....
Incidentally, a head shot is NOT advised on a bear. The skull is thick and sloping and can deflect the bullet. The US Forest Service teaches to put all the rounds into the chest cavity. I was a qualified rifleman with them in SE Alaska. We had to have at least one rifleman with each crew working in brown bear country, and that person was issued either a 12 ga. pump shotgun or a .375 magnum rifle, no hand guns allowed.
Okay, that's about what I have to say about the subject. Carry a .30-06 or larger rifle with 180 grain (or larger) bullets and save the weight of carrying that pistol.
-Winter Hawk-