It's hard to argue that a militia is "well regulated" when arms aren't generally available.
"There seems to us no doubt, on the basis of both text and history, that the Second Amendment conferred an individual right to keep and bear arms."
- Justice Scalia
DC vs. Heller https://www.law.cornell.edu/supct/html/07-290.ZO.html
It's hard to argue that a militia is "well regulated" when arms aren't generally available.