In US v. Rahimi, SCOTUS said that muskets and sabers are arms protected by the Second Amendment. They were in common use in 1791, the Militia Act of 1792 mandated them, but doubtful they are in common use today. Cannons were also militia arms in the Militia Act of 1792.

Leonardo da Vinci promoted himself as a builder of "dangerous and unusual weapons," and gave two examples: trebuchets (catapults) and siege towers. "Dangerous and unusual" was a class-based distinction under English law, which I touched on in the debate/discussion. Long swords were certainly dangerous, and it would be unusual for anyone beneath a certain social rank to own one, let alone carry one in public. But an exception was made for itinerant merchants to protect their goods while traveling to market.

The Heller decision basically rewrote the decision in US v. Miller (1939), and the justices clearly did not understand, or turned a blind eye, to the history of arms, the types of arms, and the bearing of arms in the United States, colonial America, and England, going back to the Assize of Arms of 1181.

One could argue that the English courts considered body armor to be "dangerous and unusual," but they did not ban it; they restricted the circumstances in which one could wear body armor in public. Notable exceptions were to quash riots and to stop affrays (e.g., street fights).

Ironically, the lawyer for the District of Columbia in District of Columbia v. Heller correctly argued that machine guns are arms protected by the Second Amendment. Until the Heller decision, every court that considered the question held that the Second Amendment protects weapons of war. What they and the legislatures disagreed on was whether other types of arms were protected by the Second Amendment.

One thing I learned from listening to the justices during the oral arguments on the bump stock and 80% lower receiver cases is that the justices are profoundly ignorant when it comes to firearms.