As I recall the discussions around here, reloads were the source of most of the .40SW failures. Factory ammo . . . much less frequent.
As for LEO caliber switches, there can be many reasons. .45ACP has a tremendous loyal following. Some people regard John Browning's 1911 pistol as the best pistol design ever - and they have 100 years and two world wars (plus numerous other conflicts) to back up that claim.
Sometimes it is money. Glock was renown for offering low-ball introductory prices to law enforcement agencies to gain market share. To an extent - they still do.
.40SW's initial sell point was 45cal performance with 9mm high capacity. In light of the Miami shootout, 9mm was deemed marginal - an unfair assessment in my opinion.
On bear defense - remember that the pistol is at best a third line of defense. First being detection - being aware of the bear's presence, and second being evasion - run like hell. By the time you are pulling a pistol (because no rifle is around) - you are in deep do-do and are just hoping to survive.
That said, I once heard that forest firefighters would carry a 44mag snubby. The first round or two were buckshot rounds. You basically shoot for the face and try to destroy the bear's sight/smell in an attempt to escape. The last rounds were full metal jacket - for penetration. I cannot swear that this was absolutely true but it does reflect the brutality and desperation such a close quarters combat with a bear would be - with the emphasis still being one of human escape. Upon reflection, the buckshot rounds were probably good for close quarter pissed off poisonous snake encounters as well.
Last edited by engineer151515; 08-02-2011 at 16:13..