Originally Posted by Willbe
There will always be a mechanical element if we use air (a fluid) as a motive force. However if we use purely use electricity (i.e wrap a coil round the barrel so that it becomes a big solenoid valve, the barrel being the stator, the pellet the bobbin in effect) now that could be fun!
It might need a rather large battery!
(High Voltage supply, Capacitor Storage, Conductive Projectiles and a team to service it after each shot)