However, after reading about one bear encounter after another, I've decided the .45ACP is probably a 2-legged predator solution.
That's pretty much my summary as well. When you start to look at the ballistics, the civilian SD calibers - 9mm/357 whatever/10mm whatever/45 ACP - are just a whole different class from the hunting calibers 44 magnum/454 Casull/460 Ruger/500 S&W, etc.
That sort of makes sense. The design parameters are different, so you'd expect different designs. A major design limitation on the auto rounds is that they fit in grip - and the size of the grip is related to the size of the human hand. That implies some pretty severe restrictions on the length of the cartridge. Auto's need that for potability/concealability.
Recall that when auto's were introduced by the military, they weren't anybody's (or very many peoples) primary battle weapon. They needed to be small so as to not get in the way of the soldier's primary weapon or task. Having a 45 ACP on your hip or thigh was better than nothing - but it needed to not get in the way of your battle rifle (or driving a tank, or whatever was your primary responsibility).
More recently, auto's are popular because they allow you to get a lot of rounds into a pretty concealable package.
Neither of those are very important for defense against bears. The bear is not going to care very much about concealability. From what everyone has reported about a charging bear, I am guessing that the 17th round ain't going to do you much good against a bear. Maybe give him indigestion?
When you look at the rigs preferred by most handgun hunters - especially people going after bear - they seem to prefer pretty massive revolvers in shoulder/chest rigs.
There are reasons for that - they are hunting, so they don't care about concealability, they aren't trying to hide the gun under a tee shirt on the beach.
They care less about portability - they are investing in special rigs that can make carrying a big handgun comfortable all day. Lots of rounds are not all that useful to hunters.
They are either going to be taking a carefully considered aimed shot (when they are the predator), or getting just enough time for 1 or 2 shots (when they are the prey). If they miss with the 1st shot when they are the predator, the game is not going to stick around for the 2nd. If they are the prey, ...
All of that means that the calibers/cartridges developed for altercations with two legged critters when concealability/portability/number of rounds are important are very different from calibers/cartridges developed for altercations with four legged critters where power is important and concealability/portability/number of rounds.
The range at which an altercation is likely to take place is pretty different. For the range at which wild things are shot, look at the story posted earlier on this thread. The poster reported being aware of the bear at 100 yards, and hitting him at 40 yards. That's well beyond the distance for which most auto's are designed. I know I'll get flamed - over 95% of THR 1911 owners have a 1911 that will shoot 1/2" groups all day long at 300 yards
- but the reality is the 25 yards is probably stretching the design limit of most weapons designed for self defense. Most auto's are probably designed for 7-15 yard accuracy. Not that they can't be accurate farther out, but they are tuned for accuracy at SD distances. I don't have a single room in my house where I need to hit be able a bad guy at 40 yards!
People can and have used all kinds of calibers for hunting - when they were hungry, the used what was available, which was often woefully underpowered by today's standards. They were also willing to track wounded animal a long way when that meant the family got to eat that week.
The issue I read in this thread is that the requirements - defense against black bears and big cats - pretty clearly require a hunting caliber revolver, but you don't want one. So carry something else - just be clear what you are trading off.
My advice to find a handgun hunter friend, and ask to shoot a cylinder full of loads he'd use for hunting black bear. Then shoot a 10mm auto with whatever you want in it. I am guessing that will change your perspective. Maybe not.
BTW Be careful of the "extra ounces" argument. I don't know about you, but I have seen guys built more or less like me spending lots of money to save ounces on a carry weapon when - how to put it gently - we are carrying at least
few extra ounces other places. When I am less that 10 ozs over weight, it makes sense to spend the money to save 10 ozs in a weapon. Even by the most charitable analysis, that's not true for me.
Mike