Sorry this took a bit to get up here @GingerCoffee. Lets get to it. I'll start succinctly: There is no reason to take a gun into the back country if you are not hunting. And if you're not hunting bear, there is no reason to use a gun on a bear, and no reason to think that there will be a good outcome. I'm an "experienced" back country hiker, worked for the Larimer County Search and Rescue for three years, and spent several years hiking for fun in the Lake Yellowstone area, where grizzlies are prevalent. I have never carried a gun into the back country, never felt a need to, and around a dozen encounters with bears have all ended peacefully. Lets start with the ramifications. In my state killing a bear to prevent loss of human life, is acceptable, but for any other reason it's a thousand dollar fine. In Yellowstone it would be mandatory jail time in almost every instance. In either case there would be an inquest allowing you to plead your case, but unless you can provide evidence in the case of real injury there's a huge problem. The last grizzly bear in Colorado was killed in 1979 and there was a six month investigation into whether the victim of her attack had acted in self defense (and he killed the bear by jamming an arrow into it). In encounters with bears it's very rare for the animal to get aggressive. While they are considered apex predators, very few have extensive contact with humans. They are usually more curious about humans, unsure whether we are food or not. In the case where a bear learns that humans are easy to attack/eat that animal will be hunted and destroyed. Attempts to disseminate this information into the bear community has met with little success, and it's not recommended that you count on it as a deterrent. What this means is that your dream of encountering a raging boar grizzly and subduing it with a gun shot to the head is much more likely to go like this: The hiker is doing the right thing by not turning his back on the bear. Turning and running is a really bad idea, but he made it out okay. But in an encounter like this, shooting the bear would definitely get him arrested and fined. That bear was not an imminent threat to anyone who knew how to deal with it. (At this point I imagine that someone might ask, "What if they didn't know how to deal with it?" My answer is, "If you don't know how to deal with a bear, hiking into bear country is a bad idea, and bringing a gun with you only makes it worse.") This is also an example of case in which bear spray would have saved the day. When the bear gets close you spray it, and it backs off to deal with the mace. I had a friend point out that firing into the air might scare off the bear, but in that case an air horn would be much more effective. But what about bear attacks? What do you do when the bear gets aggressive? The answer is not pretty. We call them sudden encounters, and they happen most often when the bear has been startled, when a sow has cubs, or when there is a kill in the area (bears bury their kills and come back for several days to eat it, they can get defensive when someone is getting in the way of their dinner). This is why people carry bear bells, or keep themselves talking when they walk. The best way to avoid a sudden encounter is to ensure the bear isn't startled, and making noise goes a long way. But the stark reality is that a gun isn't going to help in a sudden encounter at all. In most encounters a bear will charge, and (assuming you are facing it, which is assuming a lot) you have only a few seconds to draw your weapon before the bear is on you. After that you're in the midst of a melee with a bear, and there's very little you can do about it. But lets pretend the bear is in front of you, you've drawn your weapon in time, and you can pick your shot. You are very unlikely to kill the bear. A black bear is around 3-4 times stronger then a human of around the same weight. Their muscles are 3-4 times as dense. And if you've seen a bear get aggressive, you know that there's very little of them that isn't muscle. A grizzly is 10 times stronger and 10 times denser. There are cartridges specifically for bears that large, but few of them are made for handguns. So you've startled the bear, you've drawn on the bear, you've hit the bear, and the bear is still a huge danger to you. Studies have found that shooting and injuring a human at anything less then 45 feet gives them ample time to close the distance and attack you, in some cases even for head wounds. And that's a human, you just shot a fucking bear. I'll let the U.S Fish and Wildlife take it from here, So unless you're going into the back country with the express interest of killing a bear, bear spray* is the best way to go in pretty much every situation. Or any situation that you expect to survive. *And being aware of bear behavior, cautious hiking, and general wildlife preparedness.