Hi! Im wondering what is suitable for defence against big bears(kodiak, grizzly, polar) bear. I hear that many people uses 44 mag revolvers, but what i see is that the maximum energy you can get with that caliber, is around 2000 joule(with 340 grains bullets). Is that really enough? I know that these are heavy bullets, but still, is that enough power? Many people uses big caliber bolt rifles. What do you think is the smallest caliber to use for such a purpose? My biggest caliber is a 30-06, is that big enough? If so, what ammo should i use? I also have a 870, and think that this would be the ultimate bear-defence gun for me, due the is ruggedness, reliability and the fact that it is easier to operate when the adrenaline is pumping, then bolt rifles. Are the slugs deadly enough? Anyone knows how much energy is produced by a slug? What kinds of slugs would be best? I have only gotten the smooth - standard barrel.