not a constitutional scholar, so I can't answer that aspect of your question. I can at least give a "reasonable person" explanation though. it's not hard to te

not a constitutional scholar, so I can't answer that aspect of your question. I can at least give a "reasonable person" explanation though. it's not hard to teach someone to safely handle small arms. a responsible twelve year old can be trusted with them, as long as they have been taught four simple rules: 1. don't point gun at stuff you don't intend to shoot. 2. always treat gun as if it is loaded. 3. finger off trigger until ready to shoot. 4. know target and what's behind it. with small arms, understanding and following those rules diligently is enough to prevent virtually all unintentional injuries. they're not hard to follow, but some people can be spectacularly irresponsible. I'll leave it as a debate for another time whether/when it is acceptable to intentionally injure other people. the same principles apply to "bigger" weapons, but become a lot harder for your average person to implement. what's a safe direction to point an anti-tank missile in? how do you ensure the safety of people downrange of your artillery piece that can hit targets 70 miles away? you obviously can't use any of these things in self-defense unless you're prepared to also delete your entire house. tl;dr: it's mostly fine for people to have small arms because it's easy to use them safely. it's not easy to teach someone how to safely use missiles, mortars, etc.