My new book Armed America (Nelson Current, 2007) answers some of
the questions about what arms were in common civilian ownership when
the Second Amendment was ratified. I cite ads offering "hand grenadoes"
for sale (probably equivalent to a modern pipe bomb in
destructiveness), and the 1786 Boston ordinance prohibiting leaving
loaded firearms in buildings (as a fire safety measure) that lists not
only small arms, but mortars, artillery, and a bunch of other stuff
that would qualify as "destructive devices" today. I don't think they
included them on the list because they wanted to be complete.
There was privately owned artillery during the Revolutionary
period, although I suspect that almost all of it (because of cost and
its lack of utility for hunting) was owned by the various militia
I've long believed the same, but based more on intuition and implication than solid authority. Clayton's evidence is welcome and will be cited in the future. (I just need to remember to order a copy of his book...)
If you look at the National Firearms Act hearings before the House
Ways & Means Committee, you can see that even proponents of it, such
as the A-G and his assistant, admitted that a complete ban on sale or
possession of machine guns was beyond the authority of the federal
government, because of the Second Amendment. Background checks for
weapons seem unobjectionable from a Constitutional standpoint, as long
as they have some reasonable relationship to public safety. But that's
more a function of the person, than of the weapon.
The other counterintuitive thing that I will note here is that the Constitution probably does not prohibit firearms registration so long as that registration is not used as a tool to aid confiscation. Many founding-era communities had firearms registration laws for militia purposes.
In modern times, however, registration lists have been used to support confiscation efforts often enough that this could be convincingly argued as currently prohibited even if originally permitted.