Fake. At 2:23 in the video, the muzzle raises by an inch if not more between each successive shot. And yet, the 'downrange' result is completely different or inconsistent with the track of the muzzle. Plus the manikin clearly explodes into tiny bits (i.e. it is rigged with explosives or black powder). A real AA gun would need far more distance to arm an explosive warhead than 50 feet. Even if it were an explosive warhead that could arm in that short distance, it would need something more solid to trigger the warhead than a manikin. i.e. it would just punch a big hole through the manikin without exploding.