But is it NFA registered?

That clip is from a German movie, "Postal." The actor (cop) is Zack Ward. The movie trailer in English:

www[dot]youtube[dot]com/watch?v=3KvR0Wkbs6k

I believe the ATF reversed themselves (in embarrassment) over the "shoe string is a machine gun" letter.

Zack Ward interview on the John Kerwin Show
www[dot]youtube[dot]com/watch?v=uBLm2VNYCZM&NR=1

Zack Ward was a regular on the show "Titus."

Zack Ward Filmography
www[dot]imdb[dot]com/name/nm0911933/

I work in the movies, making stuff like this, and you just KNOW there's either going to be someone sick enough or stupid enough to try it at some point. To them I say NEDM!