Forgotten in all the rhetoric is the USSC decision in Miller that ties the 2nd amendment to “military” style weapons, saying that intent of the 2nd was to protect possesion of military style weapons by the people (militia).
That decision has been superceded. If the “military style” portion is still in effect, well, take a look at any war fought in part by irregular forces, which is pretty much every war, and you’ll soon find basically any weapon has its use. Think of Jews in the Warsaw Ghetto or Iraqi insurgents. And you can’t say it only applies to regular forces like the various branches of the U.S. armed forces. Because what is a militia, after all? Not the U.S. military, whatever it is.
Besides, Miller was bogus. I don’t even think the government was opposed at the bar. Their reasoning was beside the point, also, because the weapon in question, short-barelled shotguns, were in use by the U.S. military, even though SCOTUS ruled in favor of the state.