SpudFiles

Just tested it! I pull the trigger on the blow gun the air vents out the blow gun so I guess the piston isn't releasing off the barrel! Is it possible the piston isn't long enough not going deep enough in the chamber behind it?

Take the chamber off and reach through the bottom of the tee and move the piston by hand, see what's happening that way.

If you're filling the gun from the pilot area, you don't even need a spring

If the piston doesn't move back the piston probably isn't tight enough. Clean it very well, and give it a tight wrap of cellophane tape until it fits snug in the housing.

Movement is fine,I can put a rod down the barrel and push the piston that way,it moves freely but if your saying/labtecpower to wrap the piston to seal it better that means mine isn't long enough because it doesn't seal at all,so I guess it should fit like a coaxial piston would with same concept! I think I'm understanding it better now!you build it the same as you would a coax!

First test the QEV released all it's air out the pilot valve so I've made a new longer piston,it works fine now,but the whole setup seems to waste a lot of air or it's the blow gun wasting it!hopefully with some tuning it'll be better for multi shots!

It seems your piston isn't tight enough...

I don't think I could get it any tighter!but I'll try a new one!see how it goes!

typically if all the air is going out through the pilot, too much air can get past the piston.

Ok,no worries I'm understanding better as I go with your help!i think I was a bit miss guided at the beginning! Thankyou!or I missunderstood a tutorial