What changed my mind was moving to London. The culture shift from Florida to London was crazy, but one of the things you noticed was that the police generally don't even need to carry guns. There is still a lot of criminal violence but it tends to be less deadly. I'm not at all convinced prohibition in general, and of weapons specifically, can't work. We have too many examples where they have worked just fine. Consider the danger of automatic weapons, for example. Though a weapon like a Tommy gun or a fully automatic AK would be a good tool for mass murder, the long term automatic weapon bans in the US have put such weapons out of reach of casual buyers. You could still get one if you are a collector and you want to pay out a lot, but they are not the types of weapons commonly used by criminals. We could do the same thing for other guns if we wanted.
As for military stuff like Tanks and nukes, we have a government of the people and for the people. The military and police use these kind of weapons in our name and if we don't like the government we vote them out instead of shooting them out. I'm not a legal scholar so I can't tell you how to interpret the second amendment, but if I had my way all of that junk would definitely remain banned.
What is the difference between a semi-auto AR15 and fully auto M-16?
One can fire fully auto, making it even more dangerous. Though, I'm not comparing the danger between the two. I'm pointing out how gun control alters the availability between them. Both should be banned. That one already has been controlled is simply pointed out to preempt suggestions that such bans don't work.