That is actually a fine ass rifle, but it's old news - I was it on a "guns of the world" episode YEARS ago, it came out in 1994. The reciprocating barrel is makes it much more controllable. It's got a two round burst, I bet you the double tap speed on it beats Jerry Miculek.
Not gonna be adopted because of cost and complexity, but I would be surprised if their specialized door kickers didn't have it.