Japanese Type 3 12cm Anti-Aircraft Gun. The Type 3 12 cm AA gun as an anti-aircraft gun used in quantity by the Imperial Japanese Army during World War II. The Type 3 number was designated for the year the gun was accepted, 2603 in the Japanese imperial year calendar, or 1943 in the Gregorian calendar. It replaced the earlier Type 88 75 mm AA Gun in Japanese service. In order to address the shortcomings of the Type 88 75 mm AA gun, the Army Technical Bureau developed a larger version with superior range, designated the Type 3. It was one of the few weapons in the Japanese inventory capable of reaching the USAAF B-29 Superfortress bombers that were attacking cities and other targets in the Japanese home islands. However, despite its superior range and firepower, the Type 3 gun could not be produced in sufficient quantities to be truly effective, due to costs, lack of raw materials and damage to Japan’s industrial infrastructure by Allied air raids. Only 120 units were completed befo...