The idea that "MUH AR-15" is an inalienable right is entirely an invention of the radical orginalists on the Roberts Court. It turns out that you can completely reinterpret amendments hundreds of years after they were written, who'd have thunk it?
Fake news. See:
Presser v. Illinois, 116 U.S. 252 (1886)
1. The fact that the most recent pre-Heller Second Amendment case you can find is from 1886 doesn't exactly prove that the amendment wasn't archaic by the time Heller came around, lol
2. Presser is a weird case to cite, given that it essentially legitimized a form of mass gun control and held that state governments weren't bound by the Bill of Rights (which is obviously archaic, since most of the Bill of Rights has been incorporated by now)