Buy an 80% receiver and build your own. Federal gun laws are part of the interstate commerce act, so it only applies to guns that cross a state line. If the gun is built in your state and never crosses a state line, it does not have to be registered, and the feds have no of tracking it. Even if you don't build it yourself, you can buy a locally guilt gun. Of coarse, state laws might be a problem, depending on where you live. If you live in one of the communist authoritarian states, you're fucked anyway.