
Happy to be of assistance

If you are going to make one for you first i recommend a coaxail gun because i found them alot easier to make than Ts.
I disagree; - Guessing at both and playing with GGDT ( 40psi/ Generic Valve / 100-500ms Valve Open Time/ Flow Coef from 70-90... I get upwards to 200fps (136 mph)DR wrote:I agree; It would be nice to know the length/diameter of both the chamber and the barrel.
I don't see a hacky-sack going 'a couple hundred yards' at only 40psi with that cannon, sorry.