The order from Lockheed Marti, maker of the advanced aircraft, is worth $23.5 million.
"The GAU-22/A's reliability lends a significant advantage in lower aircraft maintenance costs, while the gun's high rate of fire and increased range bring air superiority in tactical air-to-air and air-to-ground combat situations," said Steve Elgin, vice president and general manager of armament systems for General Dynamics Armament and Technical Products.
The 25mm GAU-22/A is a derivative of the General Dynamics five-barrel GAU-12/U 25mm Gatling gun. It is lighter in weight, has four barrels and improved accuracy, General Dynamics said. It can be mounted internally or externally, depending on the F-35 variant, and has a firing rate of 3,300 rounds per minute.
General Dynamics said production on the units will begin next year at its manufacturing facility in Saco, Maine.
Notable deaths of 2014 [PHOTOS]