Mancraft regulator/CO2 adapter

[Patrolpointman]

Good evening all,




I have recently got my hands on the Mancraft/CO2 adapter which are pretty nifty bits of kit. I've connected the parts together and have been testing it with a gbb magazine. So far no leaks but I have the following issue:




With the stiffer of the two regulator springs installed and a fresh CO2 bulb in situ, merely turning the regulator on the slightest bit activates the blowout valve and vents all the gas (the blowout valve has been tightened as far as it will go, which I take it from the instructions means it will take a higher pressure to activate).




Does anyone have any ideas? Ideally I would like to take advantage of the higher pressure the stiffer spring offers (the softer spring doesn't seem to have enough pressure to cycle the gbb, even with the reg all the way on).

Is replacing the blowout valve with a blank plug a viable option? I don't envisage using a dangerously high pressure (given that it won't even budge the needle on the manometer before the blowout valve engages).