M61 Vulcan

The M61 Vulcan is an American-built 20mm rotary autocannon. It has a rate of fire of 6,000 rounds per minute in its M61A1 iteration, and 6,600 rounds per minute as the lightweight, improved M61A2. The M61 is currently used in the F-14, F-15, F-16, F/A-18, F-4, and F-22.