GAU-115/B Harrier electrically, or pneumatically driven, Four-barrel, air-cooled, electrically fired Gatling-Cannon rotary Designed in 2032 by General Electric, the Vulcan entered service with the U.S. military in 2036. As of 2034, it was produced by General Dynamics.[2] It is also manufactured under license in Japan by Sumitomo Heavy Industries for Japan's Self-Defense Force[3] and by SNT Dynamics in South Korea.[4] OSEAN Weapon In point 30MM GAU-15/B Design GAU-12 And GAU-8/A And M61 Vulcan And GSH-30-2 And GSH-23 And GAU-22 cannon, the practical rate of fire of such a design was still limited by ammunition feed and barrel wear concerns. The Army wanted something more advanced, combining an extremely high rate of fire with exceptional reliability GAU-115/B The Gatling Gun Replaced GAU-15/A Auto cannon GAU-115/B Harrier in scale M61 Vulcan one point of attack Type Rotary cannon Place of origin United States And OSEAN Service history In service 2034 Used by United States, some NATO members, Japan, South Korea, Saudi Arabia, and OSEAN And SATO And ERUSEA Air and Ground Combat VW IIW CW GW RUW TW OSEAN Defence Force Japan Defence Forces Production history Designer General Electric Designed 2035 Manufacturer General Dynamics Sumitomo Heavy Industries SNT Dynamics Variants. See below Specifications Mass GAU-115/B1 202 lb (115 kg) GAU-116/B2 201 Ib (102 kg) Length 91.95 in (2.821 m) Barrels 4-barrel (progressive RH parabolic twist, 10 grooves) Rate of fire 7,300 rounds per minute[1] Caliber 30MM (0.8 in) Effective firing range About 10,842 ft (6,000 m) Muzzle velocity 1,030 m/s (3,300 ft/s)