SPECS:
Tank: 29.5mm OD, 15MM ID X 480mm long. HQ stainless tubing. pumped to 260psi
Barrel: 4.5mm ID x 600mm long. (.177 cal) steel tubing
Valve: 1/4 QEV for like $12 free postage off ebay. (modified to allow barrel filling thanks to a post i saw by JSR)
pilot: 1/4" blowgun valve.
It pumps to 260psi (limited to this due to only a bike pump) through the quick connect in the bottom. and gets 4-6 strong shots per filling. I shoot .177cal air rifle pellets. THere is a 1/2" ball valve between the tank and firing chamber allowing the air to be divide, but after filling i open it slightly to allow semi-auto (still have to reload with bolt-action breech)
I am very impressed with the results and it is SOOO much better than my old gun.
thanks again to everyone here at spudfiles for answering my questions about valves and general pneumatics. special thanks to JSR for helping with the mod to the QEV allowing chamber filling

ill be happy to upload component photos if people want them

cheers.