at least hes got a pretty good concept, i mean imagine your friends want to play airsoft with you. so you show up with a trumpet they all start laughing at you then you just open up on them.
He's not talking about an actual trumpet. (I don't think)
On that note, I've got a bridge I'll sell you irwinner...
Anyway, I can't really see how you would call it a "vortex" unless I'm missing something. It looks more like a cloud to me and it wouldn't work very well as a cloud. The reason clouds work is that the stream of air going into the chamber throws the bbs into the air (hint:cloud) before they are forced out the barrel by the escaping air. When they are launched into the air they are separated and forced one by one into the barrel some they don't jam. This design would simply aid the bbs in jamming as they all try to escape though one hole.