>"Justice Scalia also wrote: “It may be objected that if weapons that are most useful in military service — M-16 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 to militia duty. It may well be true today that a militia, to be as effective as militias in the 18th century, would require sophisticated arms that are highly unusual in society at large. Indeed, it may be true that no amount of small arms could be useful against modern-day bombers and tanks. But the fact that modern developments have limited the degree of fit between the prefatory clause and the protected right cannot change our interpretation of the right.”

[1] https://takingnote.blogs.nytimes.com/2015/12/11/justice-scal...

I think for a weapon to be 'compliant' with US's second amendment a couple of criteria must be met

a) must be in current wide use in military

b) must be capable of being carried by a single person (which is why tanks and fighter jets will not qualify) This follows form 'individual' focus of the bill of right.

c) must be capable to aim it at a single person (which is why explosive or RPGs would not qualify). This follows from the notion that Bill of Right in general, does not condone collateral damage or collateral effect. As this is Individual's right, and therefore presumes individual's responsibility.

I also find this linguistic analysis of what 'bear arms' meant in 1791s, interesting/educational [2] http://languagelog.ldc.upenn.edu/nll/?p=255

This school only makes sense if you throw out the entire section that mentions a well regulated militia. A militia would be expected to have artillery.