AEG gas piston conversion

[Cole]

Ok, most AEG's (automatic electric gun's) are run like this http://www.arniesairsoft.co.uk/?filnavn ... anaeg.html. This design utilizes a spring and a piston to push the bb. My design is slightly different [URL=http://img158.imageshack.us/my.php?image=gpaeg6gf.jpg]. This design utilizes a gas piston instead of a spring, this would allow me to change the power out put on the fly, a regular AEG is only upgradable through "permanent" upgrades such as replacing springs. Since I think this would allow me to make a cheap powerful AEG. I would have to upgrade the motor, but since the power output i am looking for is so small, 300-500fps, it shouldnt be a problem.