I know buckshot is not always a sure stopper, and I personally know of an incident where a man shot another man at less than a foot distance in the chest with a 44 mag and did not stop him. It did not kill him, either and I knew a lady cop who shot a man with a .25 ACP, and it did not even make him flinch. There is no such thing as a gunshot throwing someone backwards. I have shot a grazing deer with 00 buck at about 15 feet and the deer simply laid down sideways. It did not bowl it over, as you see on TV.
I note that the FBI and a lot of other agencies have gone back to the 9mm. With the new loads, it takes a 357 Sig to be better, and then only a frog hair's difference. But, you pay the price in recoil and blast. I love the 45 acp, as that is what I cut my teeth with. But, I have to be realistic that it does not do anything much better than a 9mm, shooting concrete block excepted. The 9mm has much better penetration in car bodies, wood, clothing, and etc.
If I were in the woods where large bears were apt to be, I would not choose any semi-auto handgun. I would opt for a .44 Mag with Grizzly hard cast 300+ grain deep penetrators or a Remington V3 Tac 13. Come to think of it, this is a very good option for home use with the right shot shell selection.
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