As for why I think that the 2nd Amendment was intended to cover weapons of war - all the weapons of war - it was written following a successful revolution against an oppressive government, made possible by individuals already owning their own weapons. Oh, and Britain had tried to confiscate those, too. Yes, they wouldn't have anticipated the ABCs of strategic weaponry and perhaps those would be excluded, but almost anything below that has analogues in the 1700s. (And lumping automatic weapons in with atomic, biological and chemical weapons is kinda murder, arson and jaywalking IMO)