Crazy Bullet Spinning Video?

The only thing I can really add to what has already been covered is to address the lack of report from the gun.

The microphone on your average camcorder has an upper and lower range that it will pick up. Given the close proximity to the shooter, I would have to operate under the assumption that the sound is actually too loud for the microphone to record properly. There are many videos on Youtube etc of firearms being fired with fairly low volume reports for the given gun.

Edit to add:

I just rewatched the video and on the first round they found you can see the powder burns if you look close enough.