A Republic A-10A 'Thunderbolt II' on display from the KC 442nd FW, Whiteman AFB, MO.
AFRES AF79-121

Although the A-10 'Thunderbolt II' can carry a considerable amount of munitions, its primary built-in weapon is the 30×173 mm GAU-8/A Avenger autocannon. One of the most powerful aircraft cannons ever flown, it fires large depleted uranium armor-piercing shells. The GAU-8 is a hydraulically driven seven-barrel rotary cannon designed specifically for the anti-tank role with a high rate of fire. The cannon's original design could be switched by the pilot to 2,100 or 4,200 rounds per minute; this was later changed to a fixed rate of 3,900 rounds per minute. -[wiki]

Photo by Craig on Saturday, August 12, 1995 at the Fargo Airsho.