Maybe something like this or that?

But be warned, unregged CO2 is nothing to play around with if you don`t know exactly what you are doing!

Prototyping is on schedule for the next week or so. The barrels diameter should be at about 5 mm, pressure is limited to about 130 psi due to my crappy pump

I`m aware that at these pressures there is no real need for a highly specialized system, but it`s for the joy of brooding

Huh? Just took a look at this schematic. I`m not aware of the dimensions of the valves head, but let`s assume its diameter is 5 mm. At 3000 psi there should be roughly 40 kg of force holding it shut. But with a hammer of 60g and your light spring being able to open it... Well.. This confuses me :? C...

@JSR: Well, atm i`m only interested in the theory behind it. It`s the lack of proper tools, experience, space and money that keeps me from trying. So almost everything that`s required.. But of course everyone is welcome to use and optimize this idea. Just make sure you present it to the community on...

Just having a hole straight through should do the same job shouldn't it ? Hm, i`m not quite sure, but i can see vast amounts of air rushing to atmosphere before the valve closes. But with well sealing ammo and a greater area in the rear part than on the front this could do it. Not to mention the le...

Well, i tweaked it a bit (theoretical) and thought about using the pressure for resetting the.. urm, the blue part (Can find the right word for it. Is it "poppet"?). With this modification, the needed spring in the back of it must only be strong enough to close the valve in an unpressurized state. P...