I've spent time around black bears, and they are not a huge concern in most cases. A starving one can be very dangerous though and there have been a few cases where they stalked, killed, and ate humans. Anecdotal data I've read from a few online sources seems to indicate that bear spray is actually more useful on brown/grizzly bears than black bears. Not sure why. The most interesting encounter I ever had was in Northern, WI. I was out hiking early in the morning, and it began raining. Rain in a hardwood broad leaf forest can make it really hard to hear anything as the rain pap pap paps on the leaves. I wasn't particularly concerned as I spend a lot of time in the woods. However when I started hearing an obvious black bear in the brush nearby (maybe 30-40 yards) making some sounds that I interpreted as a warning, I paid closer attention. This was on an old logging road, so there wasn't anyone around. The sounds were very similar to the last audio clip labeled as "threatening" at this website. http://bearsmartdurango.org/bear-sounds/ The part that scared me was that I couldn't see the bear. But I realized there was a lot of black berry bushes around. In hind sight, I'm guessing the bear either heard me and was warning me off, or actually saw me and wanted me out of it's berry patch. I was happy to oblige, but I suspect it was a bluff from a small bear. The sound was somewhat less guttural than in the audio clip, and I'm guessing it was not particularly heavy. I've spent quite a lot of time in brown/grizzly country as well, and I have been, by accident, entirely too close to a juvenile. I wanted to get a look at the bear and approached with a small conifer tree between me and it. When I looked around the tree I did not realize just how close the bear had wandered to the tree. It was freshly out of hibernation and busily consuming grass as fast as possible. I was WAY too close. As in maybe 60 or 70 feet. If it'd sprang toward me, I would not have gotten to safety. I did manage to snap some pics though. I'll have to dig them up.. My estimate was it was around a 500 lb bear. In any situation I encounter a bear, I'd prefer to have spray and a gun both. What's key is to be aware of what's going on around you, not just to avoid bears to begin with, but to be cognizant of wind direction. More importantly, I think being aware of what the bear's behavior is telling you is more important. Bears are bullies. They will try to bluff you out of the area if they can. But they have also evolved to be top of the food chain, and fighting is part of their repertoire, and obviously they are opportunistic hunters. If a bear is charging me, I'm drawing a gun and firing as fast as I can. Plan on the bear making it to you, because they are damned fast when they want to be. Browns can run down elk. If a bear is trying to bluff you, or is curious, a little bear spray may do the trick. If one is in my tent, I'm not concerned about hitting someone else, as it's likely to be a point blank shot. So I want something big. I also don't want to disable the other members of my party by exposing them to the spray and making it harder for them to get away if the opportunity presents. There's no reason not to have both as bear spray isn't heavy enough to be a real concern to me. But I'm still bringing a gun. Consequently, a friend of mine had to use bear spray on an aggressive mountain lion a few years ago. It worked fine on a kitty.