Originally Posted by ComradeBenedict
Oh, that's what you meant. Mine(now edwards1's) worked just fine on a normal HP tank. Most of the parts were indeed aluminum, the only plastic I can think of are the ball detents, bolt front, bolt tail(both are nylatron, I believe), and the eye covers. I have a disassembly video in case you are interested, as well.
Thanks. I was looking through your review, but didn't see; what barrel threads does it use?