The folks at Morphfire have developed an airsoft conversion kit for paintball guns. The Morphfire can be fitted to Spyder Fenix, Electra, Pilot, Sonix, Xtra, Victor, and Aggressor paintball markers manufactured after 2008. It fires .20 gram BBs at 550 fps with a cyclic rate of 900 rpm.
At this muzzle energy, the BBs have enough to penetrate skin. Many airsoft clubs do not allow fully automatic guns with this much power. The Morphfire is better suited for punishing tin cans than it is for shooting your friends.
The Morph Fire 656 Spyder Pack, pictured at the top, costs $159.99.