Can someone tell me where in the 2nd amendment it says you can carry machine guns?

[TheRealJoeFish]

Perhaps somewhat in line with the above, I'd advocate (at least theoretically) - in the same way that some places put pictures of diseased lungs on cigarettes - for guns to come with a warning, or an advertisement, or a contract to be signed, that says, essentially: "If you buy this gun for self-defense, just be aware that it is far more likely to put a bullet in you or a family member than in a criminal. So, every time you imagine this gun stopping a home invader, also imagine it shooting your spouse or children. Just as long as we're clear about that."