M61 Vulcan
M61 Vulcan is a hydraulic and pneumatic autocannon. It has six barrels. It is cooled by air and fires by the power of electricity. It is a Gatling-style rotary cannon. The size of its caliber is 20 mm. It has a very high rate of fire. It has been the main gun of United States military fixed-wing aircraft since the late 1960s and is also used elsewhere. It was made by General Electric at first, and later by General Dynamics.