10 cm/65 Type 98 naval gun

A Type 98 gun mounted on the Japanese destroyer Harutsuki
Type	Naval gun Coast defence gun
Place of origin	Japan
Service history
Used by	Imperial Japanese Navy
Wars	World War II
Production history
No. built	169
Specifications
Mass	3,053 kilograms (6,731 lb) barrel & breech
Barrel length	6.73 metres (22.1 ft) bore (65 cal)
Shell	100 x 819mm .R 13 kilograms (29 lb)
Caliber	100 millimetres (3.9 in)
Elevation	-10° to +90°[1]
Rate of fire	20-22 RPM
Muzzle velocity	1,010 m/s (3,314 ft/s)
Effective firing range	Horizontal effective range: 14,000 metres (15,000 yd) Vertical effective ceiling: 11,000 metres (36,000 ft)
Maximum firing range	Horizontal:19,500 metres (21,300 yd) Vertical: 13,000 metres (43,000 ft) at 90°

The 10 cm/65 Type 98 naval gun (六五口径九八式一〇糎高角砲), also known as the long 10cm high-angle gun (長10センチ高角砲), was a light caliber naval gun of the Imperial Japanese Navy used during World War II, employed on the aircraft carrier Taihō, the light cruiser Ōyodo, and Akizuki-class destroyers.^[1][2]

The gun was considered by the Japanese to be their finest anti-aircraft artillery weapon. It had excellent elevation and reach and could traverse quickly.^[3] Its rate of fire was good, though not as good as the U.S. 5”/38 dual-purpose gun.^[3] Its directors were also poorer, and the 3.9”/65 lacked the radar proximity fuse developed by the Allies.^[3] After the end of World War II, the gun remained in service on the two Japanese destroyers ceded to the Soviet Union and the Republic of China as war reparations.

The Allied forces first captured a shore-based twin-mounting of this weapon at Iwo Jima.^[4]