If you have a leak from the LPR set screw, then one of the outer LPR orings near the set screw is bad. It may not look bad but swap them out anyway.
A leaky LPR will not be able to maintain enough pressure to cycle the gun.
Make sure you don't have the front on/off knob in the off position as well.
ETEK 3LT, with 14" Ti boomstick and cure 3 + bolt F/S
Vanguard creed eyes, membrane, bolt pin, detents, gaskets, schraders, orings and more F/s[/color]
Old school angel poppets/cup seals(LCD and A4/speed), spring detents(not sure which models) F/S