If we're talking about bear defense, IMO, this is a strawman argument for something like a PMR.The only way to stop a living creature on demand is to disrupt the CNS. It does not take a large diameter bullet to do so. How many inches of penetration does it take to reach a bears brain?
There are well beyond a hundred documented accounts of handgun use in defense against bears. Following the actual field data (much like the 223 thread) there are some clear trends that come out.
* 9mm and beyond, handguns are extremely effective (like 98+%) at stopping a potential bear attack.
* A CNS hit is absolutely not required to stop a bear attack. Not saying that you're saying this, but I frequently read things like "The only way to stop a bear with a handgun is a CNS hit, so....blah, blah, blah." If a CNS hit is what was required to stop a bear attack, handguns would rarely be effective.
*In the vast majority of successful handgun uses in potential bear attacks, well over 80% and probably closer to 95%, a CNS hit is not made. Sometimes the bear dies from the hits, sometimes it doesn't, but the attack doesn't happen, or is stopped.
*Very obviously, with the level of success handguns have shown to produce, expert level shooting is not what accounts for that success. If that were the case, handguns would seldom be successful. Few, if any of the accounts show signs that the shooter was an "upper echelon" expert with a handgun. There just aren't that many of those shooters out there for the success rate to be as high as it is, and they're certainly not stopping attacks with CNS hits. Exactly the opposite actually.
*The handguns that have the most inconsistent results are the many cases of rimfire handguns used in bear defense. Granted, as stated, 22WMR isn't the same as 22LR and 22LR is probably what has been used in most of those cases, but it's closer to 22LR than the rounds that consistently show very high percentage success rates. There's very little, if any data on how well it works compared to other rounds. Maybe it works great, IDK, but there's not much data at this point to say one way or the other.