It sad to see you out of the competition, btrettel. I still look forward to seeing how the FANG 3 works out. I'm warming up to the idea of revolving turrets and you just might provide the inspiration for me to try one of my own.
Thanks for the compliments everyone, I appreciate it. I expect the gun to be finished this weekend if everything works out. Today I cut the u-channels and side walls. Tomorrow I'll assemble the first magazine. I've also decided on a magazine retention system. From handling the gun quite a bit, I noticed how desperately it needed a foregrip for better control. There is almost no convenient place to put your other hand when shooting. So, I came up with the idea of welding a 1/4" pipe cap to the bottom of the gun (threads pointing down), just in front of the magazine port. I will thread the sleeve end of a quick-release coupling into that cap so that it's vertical and the socket is on the bottom. Then, I will connect a plug end of the coupling parallel to the front face of the magazine with the plug sticking up vertically. The magazine will snap right into the quick-release while the quick-release provides me with a secure spot to rest my hand. I hope that explanation made sense...
Anyway, here are most of the components in all their glory:

All of the air fittings have been secured with high strength threadlock so everything stays in place nicely. I made the stupid mistake of putting threadlock on the gauge... and then threading the gauge in so that it was upside down. In the process of unscrewing it, I completely f*cked it up because the threadlock held it so well.
Video of just the pneumatic components operating:
http://s237.photobucket.com/albums/ff15 ... IM0919.flv
Video of the whole action cycling dry:
http://s237.photobucket.com/albums/ff15 ... IM0920.flv
While cycling the action, I discovered that the barrel/bolt was still a bit too tight of a fit inside the body of the gun. It completely seized a couple times. I will have to sand it down some more and keep the whole thing lubricated with WD-40. Corrosion seems to contribute to the problem as the inner surface becomes rough after being exposed to humidity.
The bugs I've encountered along the way so far are easy to fix... But I'm
really hoping the thing feeds and ejects properly... It sucks that I had to come all this way on faith alone without any reassurance that the system would actually work. Soon enough I'll see if all the work payed off...