I ran it for about 500 rounds today from a 3500psi fill on my 45ci bottle. It got cold from the HPA, it's such an air pig. Not much worse than a mag I guess, but really odd. I may try a different barrel on it. Startled lots of people. Anyone that knew what it was would say "oh, wow! A working
A note about the feedneck. It was red-loctited in and it had come off at the field as I was installing the halo. After I cleaned the old loctite off, I saw that the fit was not pressed in at all, more like "dropped in". It had enough clearance that I would have liked to use some JB weld to fill the gap, but all I had available was some more red loctite. After letting it set for about three hours, I pushed it into service and it did fine. That's why it only got 500 rounds of play.
All that after chucking the whole upper body in the lathe to keep the feed neck undisturbed.