A couple of friends of mine were out working their dogs (airedales) and they picked up a bear. The dogs tracked it for 2.5-3 miles before it treed. It took my one friend about 30 mintutes to get up in the draw with the other guy about 15 min behind. It was a small male, about 220lbs. The bear must've caught his breath and decided he had enough of that tree and the dogs had lost interest. He climbed down and went after one of the dogs. When he decided there was no way he was going to catch an airedale he turned towards Tom. 4 shots of .40S&W put the guy down. The first three "paused" him, but it took the 4th, at 15 feet, through the neck/spine to ball him up. There's been a lot of discussion about bear attacks. This isn't a perfect example since the bear had every reason to be surly and won't act the same way if you just happen across him as he would if you scared his butt up a tree. Whether the .40 is "enough gun" or not, in this case it was. Which doesn't prove much of anything except keeping your wits about you when things get nutty is darn important.