I think non-lethal devices are better to have for two legged scum. Practice clean camping in bear country, that is usually enough. One time in all my years of back woods camping did a bear bother my tent. It was an adult black bear, I yelled at it, it pushed its nose on the tent, I pulled the hammer back on my sleep aid and took aim. The bear promptly left.
I guess the fellow knew what was coming next. If your going to use a firearm, choose one that will actually stop a bear, big or small. The Alaskan by Rugger is one in say at least .44 mag, better yet a .454 or a .480 cal. Or a 5 1/2" S&W .460, that has enough weight to tame such a hot round. Practice often.
I've found being ready and properly armed is enough usually. Never needed to pull the trigger yet. Its hard on the ears when you do.
Try not to tempt them in the first place. Thats a challenge when your smelling ripe though.