From wiki: * In regard to the scope of the right, the Court wrote, in an obiter dictum, “Although we do not undertake an exhaustive historical analysis today of the full scope of the Second Amendment, nothing in our opinion should be taken to cast doubt on longstanding prohibitions on the possession of firearms by felons and the mentally ill, or laws forbidding the carrying of firearms in sensitive places such as schools and government buildings, or laws imposing conditions and qualifications on the commercial sale of arms.”[49]
The Court also added dicta regarding the private ownership of machine guns. In doing so, it suggested the elevation of the “in common use at the time” prong of the Miller decision, which by itself protects handguns, over the first prong (protecting arms that “have some reasonable relationship to the preservation or efficiency of a well regulated militia”), which may not by itself protect machine guns: “It may be objected that if weapons that are most useful in military service – M16 rifles and the like – may be banned, then the Second Amendment right is completely detached from the prefatory clause. But as we have said, the conception of the militia at the time of the Second Amendment’s ratification was the body of all citizens capable of military service, who would bring the sorts of lawful weapons that they possessed at home.”[50]*
https://www.law.cornell.edu/supct/pdf/07-290P.ZO
*"Although we agree with petitioners’ interpretive assumption
that “militia” means the same thing in Article I and
the Second Amendment, we believe that petitioners identify
the wrong thing, namely, the organized militia.
Unlike armies and navies, which Congress is given the
power to create (“to raise . . . Armies”; “to provide . . . a
Navy,” Art. I, §8, cls. 12–13), the militia is assumed by
Article I already to be in existence. Congress is given the
power to “provide for calling forth the militia,” §8, cl. 15;
and the power not to create, but to “organiz[e]” it—and not
to organize “a” militia, which is what one would expect if
the militia were to be a federal creation, but to organize
“the” militia, connoting a body already in existence, ibid.,
cl. 16. This is fully consistent with the ordinary definition
of the militia as all able-bodied men…This holding is not only consistent with, but positively
suggests, that the Second Amendment confers an individual
right to keep and bear arms (though only arms that
“have some reasonable relationship to the preservation or
efficiency of a well regulated militia”). Had the Court
believed that the Second Amendment protects only those
serving in the militia, it would have been odd to examine
the character of the weapon rather than simply note that
the two crooks were not militiamen. *