“In Heller, arms and devices that have been banned a long time, ergo “not in common civilian use,” the ban is constitutional. This was done so that bans on military arms (in particular, the M-16 and others banned by 1986 Act) would stand.”
For that matter, the entire “in common use” argument is fallacious. Congress can issue Letters of Marque and Reprisal to private citizens (or, presumably, to companies). When issued during the Revolutionary War by the Continental Congress (arguably pre-Constitution), they were issued to those individuals who owned ships with many cannon on them - and I guarantee that this was not “common” in any fashion, as one had to be enormously wealthy to own such equipment. Ditto for the War of 1812 (arguably POST-Constitution), when identical practices were followed, and Letters given to similarly enormously wealthy people (i.e. these ships were not in common use).
Yes, I’m saying that the Supreme Court is just plain wrong in this aspect of the Heller decision - but the practical reality is that this language probably had to be put in to get a majority that otherwise pretty well affirmed the 2nd Amendment. We shall have to wait for a more favorable Court (i.e. sans Breyer and Ginsburg, hopefully both of whom will be replaced soon by Trump).
I consider people who hallucinate things like "gay mariage is right there in the constitution" to be literally insane.