Jebus, it took a second for me to realize that it fires rounds from a vulcan minigun. It's freaking AA round. the first comparison I heard was that the rounds are about the size of a glass coke bottle, and the force could slow a plane like the A-10 down as it was fired.
Might be better off with the minigun! The M61 weighs 202lbs and has a 10 round per second rate of fire :D