I say this as a lefty: the US defines the militia as essientially including every able bodied man. Since it was written before the 14th amendment, it probably would be interpreted now as every adult.

https://www.law.cornell.edu/uscode/text/10/246

In fact the first weapon ban to hit SCOTUS, US v Miller, hinged on the fact that sawed off shotguns had no military application, which was legal basis allowing them to be banned. The court at the time considered bans of military weapons unconstitutional.