Here are some pics and 2 small videos of an electrically powered
slug thrower or "BB Machinegun". It operates like a "centrifuge" gun
and can launch 5/16" (7.9mm) diameter delrin spheres at 
460 ft/sec (140 m/s). The launcher can fire single shots, 
3 shot bursts or full auto (5 shots per second). 
The magazine capacity is 50 shots.
It is powered from a 4 to 7 cell NiCd pack. 
It is called a "PEST" or Portable Electromechanical Slug Thrower. 
*grin*

Please see the webpage:
http://www.geocities.com/pest3125 
- Please try later if the site goes down due to bandwidth limits

The photo album is at:
http://photos.yahoo.com/pest3125

Files in dropbox:
pest.txt - this file
pest1.jpg - pic1
pest2.jpg - pic2
pest3.jpg - pic3
pest-4cellNiCd-delrin1.mpg - mpeg1 video
pest-4cellNiCd-delrin2.mpg - mpeg1 video