That thing is like a water hose! Think of the fun you could have with it. A little squirt here, a little squirt there...
You’re thinking of the rotary guns, I think. This chain gun has a single barrel and fires rather slowly in comparison.
This chain gun is very cool and has quite a unique sound to it as you can hear the chain clinking as it fires.
http://www.youtube.com/watch?v=m1JIAB5IAxE&NR=1