BB machine gun

These devices shoot large numbers of small diameter ammo, typicaly steel BBs or plastic airsoft bbs. Their air consumption is huge, rendering them practicaly non-portable; even a sizable tank would be emptied in a couple seconds.

There are a couple common designs:

• A cloud chamber agitates the projectiles by blowing the air stream up through them. The agitated bbs then get sucked into the barrel.

• A vortex block blows the bbs around and around the inside of larg-ish diameter hole, which has a tangetal hole leading to the barrel drilled in it.