12.7 cm/40 Type 89 naval gun

The 12.7 cm/40 Type 89 naval gun was a Japanese anti-aircraft (AA) gun introduced before World War II. It was the Imperial Japanese Navy's standard heavy AA gun during the war.

12.7 cm/40 Type 89 naval gun
Type 89 gun mounted on Chitose
Type	Naval gun anti-aircraft gun
Place of origin	Empire of Japan
Service history
In service	1932–45
Used by	Imperial Japanese Navy
Wars	World War II
Production history
Designed	1928–32
Produced	1932–45
No. built	~1500
Variants	Type 88
Specifications
Mass	3,100 kilograms (6,834 lb)
Barrel length	5,080 millimeters (16 ft 8 in) (bore length)
Shell	Fixed 127 x 580mm .R
Shell weight	20.9–23.45 kilograms (46.1–51.7 lb)
Caliber	12.7-centimeter (5.0 in)
Breech	horizontal breech block
Elevation	-8° to +90°[1]
Rate of fire	8-14 rounds per minute
Muzzle velocity	720–725 meters per second (2,360–2,380 ft/s)
Maximum firing range	9,440 meters (30,970 ft) at 90° (AA ceiling) 14,800 meters (48,600 ft) at 45°

The Type 89 was adopted by the IJN on February 6, 1932, and was the primary anti-aircraft gun on new aircraft carriers, battleships and cruisers, most commonly installed in twin gun mounts. As IJN ships were upgraded in the 1930s and 1940s, older AA guns such as 8 cm/40 3rd Year Type naval gun and 12 cm/45 10th Year Type naval guns were replaced with Type 89's.