It is in Russian, but it has high-speed video showing the unusual muzzle break, the reciprocating barrel, and the two-shot/one recoil in action. One thing I noticed was the barrel flex - I know it is a factor but I have never seen it captured in video before.
http://www.youtube.com/watch?v=r4e4QcbEZP8&feature=related
http://www.youtube.com/watch?v=r4e4QcbEZP8&feature=related