The only problem with defending yourself against a bear is you are only going to have a few seconds, five maybe, to get into action and get the job done. Fifteen shots are not going to do you any good as you will never have the time to shoot more the two maybe three shots. Better to take a second and make sure where you are putting the bullet. If you are going to carry a semi-auto then by all means carry a .45 ACP. Personally I carry a 4" .44 magnum for protection when I HAVE TO. When in bear country, I live in bear country, if I'm going for a walk to just smell the flowers or look at the birds then I carry a rifle. Some people like to carry shotguns, if you are one then make sure it's full of Brenneke slugs loads. Forget buckshot! Even 000 buck isn't a good choice for stopping a big dangerous animal like a bear. Lawdog