Guns › Oerlikon FF九九式一号機銃九九式一号機銃九九式一号機銃Modification ofOerlikon FFCaliber20 mmService193119321933193419351936193719381939194019411942194319441945Japan · China≈ Aug 1940 – Sep 1941Japan · Pacific≈ 7 Dec 1941 – Feb 1944Japan · Southeast Asia≈ 8 Dec 1941 – 9 Apr 1942Aircraft 6193119321933193419351936193719381939194019411942194319441945A6M2 Model 11≈ Aug 1940 – Sep 1941A6M2 Model 211,540≈ 17 Feb 1941 – Sep 1941≈ 7 Dec 1941 – 5 Jan 1944≈ 5 Apr 1942 – 9 Apr 1942G4M1 Model 111,170≈ Jul 1941 – 1 Sep 1941≈ 8 Dec 1941 – Feb 1944≈ 8 Dec 1941 – 15 Feb 1942A6M3 Model 32343≈ Aug 1942 – 5 Jan 1944A6M3 Model 22560≈ Dec 1942 – 5 Jan 1944G4M2 Model 22429