I used to be very pro-gun/weapons, then when I became Christian, I became less so. However, my official position for USA's gun laws is that anyone not on probation/parole/court conditions otherwise should be allowed to own any small arm they want and they should be able to be freely bought as any other commodity, I'm a bit libertarian in that regard, I also believe in legalization of drugs, too, so yeah. I don't believe my goal is terribly practical in today's society, as you'd need to legalize drugs to quell the gangs, that, and because not every other country on earth would do the same policy, USA would become a major arm smuggling exporter. And generally where arms are smuggled to, it's bad people breaking laws, it's usually not good people getting smuggled guns, as good people tend to follow laws even if they think they're silly.
However, I don't think they're a "good" thing, as they're made to be used for killing, really. This world unfortunately requires killing because of the evil in it, and what I as a Christian believe is the fallen state of mankind and sin of humanity. There are going to be people that commit evil actions for one reason or another, and someone needs to stop them, and weapons allow mankind to not be ruled on just strength alone.
Without weapons (which is impossible, as sticks, rocks, etc could be used as weapons) only the people with brute strength alone would rule. Weapons act as an equalizer, they allow you to be more powerful than your opponent if you lack physical strength to otherwise defeat them. So the advent of weapons, especially firearms, is kind of a good thing. A firearm, for example, is just as useful in the hands of a woman compared to a man. So with a firearm, a woman is just as powerful as a man, and a man can no longer overpower her. So main point, the "good" part about weapons is, they allow weaker parties to be even against otherwise stronger or more numerous parties. However, this can be flipped around, too, and a small group of people with lots of weaponry can rule over a large group without it. You don't really "win" really.
So, to summarize, I'd say weapons are made as a result of general human faultiness, and evil. So that would sort of make them evil if you think about it that way. They don't have to be evil, you can just think they're cool and collect them and whatever, and if you never do evil with them, well, hey, they're not evil in your hands anymore. It's almost a repurpose, turning the evil of weaponry's frown upside down if you would. On the same point, in USA, total homicides are around 15K people a year. In USA, there's 40-50K auto accident deaths a year. So without even intent to kill (usually) we manage to kill more people just driving places. Think about it, in your car, you have the opportunity to murder dozens of people everyday, just run up on the sidewalk and run people over, but you don't. Same with owning a gun or other weapon, just because you have the means to kill someone doesn't mean you're going to, because as I've pointed out "cars" manage to kill more people than weapons do in US, and they're not even intended for that purpose.
A lot is very much culture, too. People very much are "scared" of guns in today's society. It's understandable to a point. Guns are the modern weapons now. At the same time, show them a sword or knight suit or whatever from a thousand years ago, and they won't get the same emotional reaction, though both are meant for the same purpose. You no longer see people getting murdered with swords or whatever, so they become more museum pieces, of even things people think of as beautiful or romantic, but the history of them is just as bloody if not more so than firearms.
So yeah, I'd say necessary evil to sum it up easily, but it's a pretty complex issue.