>>2835565
Most 12ga slugs are soft lead so the slugs flatten out (pancake) almost immediately upon hitting bone, they also lose energy like an anchor dropping the farther out it flies (12ga slugs lose about 800 ft lbs of energy by 100 yards). The only reason they are chosen is because slugs and shotguns are cheap ($1/rd instead of $4 for magnum pistols), handy, and it dumps 1,500 ft lbs of energy into the bear immediately, which will fuck anything up. Slugs are also a little bit easier to get on target at close ranges because of the huge bore. Buckshot is generally worse than standard bore pistols on bears because they don't penetrate very far even if they spray more energy into the bear in total.
On the thread theme, there are cases of spray completely failing and a bear killing two people in a single incident. There are also cases where a .44 mag failed to immediately kill a bear due to poor shot placement and the bear charging from a hidden tree line. If you live in Canada you're not allowed to carry handguns in general and it's risky to carry a shotgun or rifle around on a camping trip or hike because Canada isn't general open carry like the USA. So in Canada, spray is sometimes all you can safely carry. In the USA however, we've got guns down to a science, especially in bear country and a firearm is a smart thing to bring with you in any backcountry, there are 100+ cases of firearms successfully stopping charges in the USA in recent decades (including 9mm).
General rule of thumb for bear defense ammo.
FMJ, TMJ, and especially hardcast bullets are best. You want penetration over expansion. You don't necessarily need to mag dump or rely on huge mags, as in a dangerous charge you will likely only have time to get 2-4 shots that you can get off (theoretically) into the bear. Small rifles (.30 bore >/=) and magnum power pistols (including magnum class semis) work fine on big bears, and most of the reported kills are actually with sidearms, due to accessibility.
