co-axial diaphragm
i have a question about a co-axial pneamatic im building. im not sure were to put the schrader adapter, i have heard that if u put it behind the diaphragm at the back of the gun then when u disconnect the pump it will fire. does it matter were i stick it? by the way it has a 2" chamber and a ".5 inch barrel.
why doesn't anyone check the how-to's for these? 
look at the coaxial valve diagram, its pretty straight forward. but also, you need to pressurize the part opposite the chamber behind the piston, and then you need a pilot valve. when you pressurize that chamber, it will push the valve forward, when you open the pilot valve it will create a vacuum which will pull the piston back and release the rest of the pressure out the barrel. hope this helps 
look at the coaxial valve diagram, its pretty straight forward. but also, you need to pressurize the part opposite the chamber behind the piston, and then you need a pilot valve. when you pressurize that chamber, it will push the valve forward, when you open the pilot valve it will create a vacuum which will pull the piston back and release the rest of the pressure out the barrel. hope this helps 