General Dynamics Armament and Technical Products has introduced a 3 barreled .50 Caliber Gatling Gun capable of firing 1,300 shots per minute. That would be over 975,000 grains (140 pounds) of lead and at $5 per round cost $6,500 per 60 seconds.
I would love to have one of these mounted on my truck. However, even if I were able to afford the gun there would be no way for me to afford to feed it.
Hat tip to Dustin.