Sure , pepper spray is about the best first line of defence for a bear.
But it doesn't always work.
Then what?
Well, then you're probably dead - the bear is probably on you and it wouldn't matter if you had a flare pistol or a real one, you'd be hard pressed to bring it into action. The flare is not going to do any appreciable damage to the bear in any kind of time frame that would help you out, and if the bear is on you it might just make it madder. Not to mention the flare might just fall back on you - hardly improving your situation.
You can get those pen-launched bear-bangers - those have met with somewhat mixed results but if you had one of those and a can of pepper spray you could probably deter the bear if it hasn't made up its mind to attack you yet, and stop the bear if it does.
Its a shame, how many guys have a safe full of large bore handguns but are forced to tramp around unarmed by our laws.
That much is the cast iron truth.
I would imagine they would also be decent anti-rape and mugging tool for people in big provincial parks and other biking/hiking trails near or in cities.
That has actually happened, and yes, it can be effective. The difference is 1) it has a deterrent value against a human - the guy's gotta wonder what the flare gun will do to him, if all he's got is a knife he may think twice and move on to easier targets, and 2) they've been known to get thru cloth and sit against the skin burning - a 400 lb bear may be able to shrug off that kind of pain and keep attacking, but humans generally won't.
However, carrying one in the city COULD land you with a weapons dangerous charge, and if you actually pull it it becomes a firearm under the criminal code, with all the wonderful reprocussions accompanying that.
honestly, for bears you'd be better off with a can of spray, and if you feel the need for more, take something like a winchester trapper carbine in 44 mag with a 16 inch barrel and cut the stock till the gun is at the minimum OAL allowed. replace the wood with synth if you want to lighten it further. Then rig a scabbard for it that goes on your backpack and stays out of the way.
That way if you spray the bear but it doesn't leave, you'll have time to get out your gun and shoot it. You'll likely be more accurate firing a cut-down winnie one handed than a flare gun anyway, and you'll actually do some real damage to the bear. And you'll have a second shot pretty quick. And anyone who thinks a 44mag isn't enough to stop a bear really has no business thinking a wimpy ass light weight flare trundling along at a few hundred feet per second is going to do any good at all.
I've heard of a few people in alaska doing something similar with single shot shotguns - cut 'em way down and if you have to stick it in the bear's face and fire. At least one old guy who's son's a guide actually successfully defended himself against a bear with a rig like that. Very light, easy to carry. A real ##### to practice with i'd think - but better than nothing if you're going to be mauled.
For that matter - if you like flares you'd probably be better off with a REGULAR magnisium flare that you could hold in your hand. Lots of smoke, lots of fire and heat, too bright to look at, hissing noise, - i can imagine that a bear wouldn't quite know what to make of it.
If he got mad at it - give it to him. A few chomps on that and he'll have other things to think about than you.
I think if you were thinking 'flare' one you could hold in your hand would be much more effective than one that's likely to bounce off of him and burn somewhere else, and might scare him right into your lap.
If you REALLY wanted to be clever, take a walking stick with a small holder for a flare, then light it up if you see one and stick it right in his face if he comes at you. If he swats at it or bites at it you can always light another one, and he's likley going to regret his actions pretty quick when his paws or face are actually burning or singed.
