Well as long as they track the persons picture, and have a gun show on monday, get the persons name and social security number, do a background check, and have ANOTHER gun show on Wednesday where they actually get the gun (or have background checks done beforehand so you can get a badge or something) thats okay.
You're barking up the wrong tree if you're asking me to defend Ferraris... But you knew that? Again, why the fuck would you need a gun of that calibur? If you have a pistol or a shotgun, you can protect yourself against a robber, and if you go batship a cop can drop you after you get one shot off or something. With a machine gun like that, the equation is off.