80% machined lower receiver is not considered a fire arm under federal law and requires no FFL. It can be bought like chunk of metal in most states with no ID.
It only takes a drill press and basic hand tools to bring it up to 100%.
The question becomes: at exactly what point does a piece of steel become a firearm?
The totalitarian governments simply make it illegal to have any part of a firearm without a license, and make it illegal to make a firearm without a license.
The Second Amendment should preclude that here in the United States.
>The question becomes: at exactly what point does a piece of steel become a firearm?
81% by definition