RE: .45acp powerful enough for field duty in southeast?
A GOOD 45 auto is more than a match for a black bear and better than .357 for what you are wanting. A .357 is a fine round but almost any loading of it will be SWC or HP bullet and both will try to expand and do cute things rather than just simply punch deep into the vitals. The .45 has much heavier bullet, plus with a good reliable automatic, if a bear just decides he wants to try you on, you can almost guarantee that he's going to get a face full of bullets, not the 2 or 3 you might get off with revolver in sudden suprise or rush attack. I've actually seen 45 hard ball ammo penetrate farther than 44 magnum. The old 230 gr round nose bullet out of 45 is hard to stop.