 In early 1945 , the sisters were rearmed when their 8 @-@ inch guns were replaced by four 12 @.@ 7 cm ( 5 @.@ 0 in ) Type 89 dual @-@ purpose guns in two twin mounts and four of their remaining 6 @-@ inch guns were removed . When firing at surface targets , the Type 89 gun had a range of 16 @,@ 100 yards ( 14 @,@ 700 m ) ; they had a maximum ceiling of 30 @,@ 970 feet ( 9 @,@ 440 m ) at an elevation of + 90 degrees . Their maximum rate of fire was 14 rounds a minute , but their sustained rate of fire was around 8 rounds per minute . Their light anti @-@ aircraft armament was significantly reinforced by the addition of 9 ( Iwate ) and 14 ( Izumo ) license @-@ built Hotchkiss 25 @-@ millimeter Type 96 light AA guns in single , double and triple mounts and two 13 @.@ 2 @-@ millimeter Hotchkiss machine guns in single mounts . The 25 mm ( 0 @.@ 98 in ) weapon was the standard Japanese light anti @-@ aircraft gun during World War II , but it suffered from severe design shortcomings that rendered it a largely ineffective weapon . The twin and triple mounts lacked sufficient speed in train or elevation ; the gun sights were unable to handle fast targets ; the gun exhibited excessive vibration ; the magazine was too small and , finally , the gun produced excessive muzzle blast . The weapon had a maximum range of 24 @,@ 600 feet ( 7 @,@ 500 m ) , but effective range was only about 4 @,@ 900 – 9 @,@ 800 feet ( 1 @,@ 500 – 3 @,@ 000 m ) . 
