The cut off for reliable stopping performance of any kind of wild animals is .40 cal because we cannot depend on proper penetration/wound cavity combo from the lighter bullets. I personally know several conservation officers that have successfully shot and killed black bears with there 40S&W's 180gr @ 950fps but I will not recommend that slower velocity round either.
A 357 Sig which is basically a 357 magnum in semi-auto form is a wonderful cartridge but it just doesn't have the performance necassary for reliable stopping power due to the smaller diameter and lighter bullet weights that are commonly loaded in either of these cartidges. Yes these bullets are fast but I can also load my 10mm's with 135gr bullet's to 1800fps or 150gr bullets to 1550fps but will not even think about using these lighter loads when in the bush due to there lack of penetration.
When in the bush in BC mountain lions are not the animal that we need to be mostly concerned about so we need to carry a firearm that will dispatch the larger animals that we encounter.
Colin don't get me wrong the 357 sig will kill a mountain lion and even black bears it is just a matter of how fast it will kill it which should be what concerns us the most.
There is a fellow JJ Hack that is on the Greybeards Outdoor forum that guides black bear handgun hunters in Washington State. He writes that he has been in on over 300 black bear kills mostly with enforcement officers that wanted to use their service handguns during the hunts.
He has witnessed and in his words "the pathetic performance of 9mm's, 357's and 45acp's on black bears". Yes they eventually died but after he watched repeated bullet impacts into the treed bears where the animals barely flinched he cannot recommend anything less powerful than the 10mm/41 mag and recommends the 44mag with 240gr HP's which is what he carries.
He states that anything under 10mm/41mag will not reliably stop a black bear.
I have personally shot a black bear @ about 8 yards with 190gr Sierra FPJ's with a muzzle velocity of 1300fps and the performance was definately not awe inspiring. I was fortunate to have it run away from me rather than towards me after I shot it. I was able to double tap it in the lung area and hit it only once more as it was running quartering away from me. It made it about 60 yards before it dropped. I did take more shots as it was running but missed...
I have also shot a black bear with the 44mag with 270gr Gold Dot FP's and the response from the bear was devastating with it dropping almost instantious.
I carry my 10mm's mostly in the bush when it is either winter and the bears are sleeping at which time I load up with 200 gr XTP's @ 1280fps or I am jumping in and out of my truck a lot due to ease of loading and unloading the guns and loaded with the 190gr loads I mentioned earlier.
When the black bears are out to play I carry my 44mag with 240gr or 270gr Gold dots or 45 Colts with 300gr XTP's or 330gr WFNGC's @ 1300fps and when I am in grizzly country I carry my Ruger SRH in 454 Casull loaded with Cast Performance 360gr WLNGC's @ 1520fps.
Like I stated earlier the best rule of thumb is carry a handgun/cartridge combo that can get the job done not one that might get the job done.
At the least I see this as an excuse to buy another handgun......
