I realize ball valve launcher's are relatively poor performers. At first I was aiming for a coaxial piston pnuematic as they're far more compact than even a ball valve, however I opted for a ball valve simply because I wanted the ability to disassemble and modify the chamber, plus they seem to be far less finicky.
Anyway, simple design with only 4 vital components
-36" long, .56 cal barrel
-13" long, 1/2" copper reservoir
-3/8" ball valve
-Lock aka mechanism which will allow the ball valve to snap open with the pull of a trigger I don't know if this is the optimal barrel/chamber ratio, however I want to keep the chamber on the small side while still using the long barrel to it's fullest. I've tested it already and the results are very exciting, I used an old bike pump and with just 2 good pumps (and using my hands to open the valve) I was able to shoot a 1/2" ball bearing faster than a slingshot with powerful flat bands.
![Shocked :shock:](./images/smilies/icon_eek.png)