Kavanaugh's dissent is kinda hilarious in this context.
> The original constitutional principles do not change absent a constitutional amendment, but the relevant principles— both the rules and exceptions alike—must be faithfully applied not only to circumstances as they existed in 1787, 1791, and 1868, for example, but also to modern situations that were unknown or unanticipated by the Constitution’s Framers.
This, of course, doesn't include machine guns.
I've laughed ever since United States v. Jones (2012), the GPS tracker-stuck-to-vehicle case.
The justices actively debated what the historical equivalent of 24/7 digital tracking would look like in 1791. This prompted the famous hypothetical of an officer secretly squeezing into the trunk of a horse-drawn carriage to track someone's movements over several days.
The issue here is that there's no practical way to ever update the Bill of Rights in the 21st century. Bug or feature?
Radio, TV, cameras
That said, breech loaders were used by the British during the Revolutionary War (the Ferguson Rifle) and multiple shots from a single barrel using multiple "touch holes" was well known.
And then there's Puckle's gun.
Humans are rationalizing animals, not rational ones.
Machine guns are illegal in the US. SCOTUS has never ruled there is an individual right to own machine guns.
Fully automatic guns maybe not, but the founding fathers definitely knew about repeating firearms, they had more than a few offers to purchase them, both for military uses and as private citizens. They just denied to because it was expensive to purchase and maintain.