That’s pretty funny 
He should never have posted this video online. Once Governor Northam of Virginia gets wind of this he will seek to ban and confiscate the deadly assault trombone.
Well probably ALL Trombones, lest people convert them to Assault Trombones. And anything that looks like a trombone… trumpets, coronets, flugelhorns. Think of ALL the brass in a band! Why do you think they make them all sit in their own “section”? THINK OF THE CHILDREN!
Did you say brass? What if they re-load that and use it in self-defense? There might be some issues with that. How much breath did they use, and how often do they practice with it? 
I actually thought it was a blunderbuss. Then I realized it was a trombone and I feared for my life.
How can you call it an “ASSAULT” anything??? It doesn’t have a barrel shroud, pistol grip or a retractable stock and it’s not scary black. Sheesh. 
Really cool tho. Good on the kid for his military moves. 
Trombones have retractable slides and adjustable counterweights. I just don’t see why any civilian musician needs those on an instrument.