| 8"/55 caliber naval gun | |
|---|---|
,_circa_in_December_1942,_following_the_Battle_of_Tassafaronga.jpg) No. 2 turret of USS New Orleans following a Japanese torpedo-initiated explosion of the forward magazine during the Battle of Tassafaronga on 30 November 1942. | |
| Type | Naval gun Coastal defence |
| Place of origin | United States |
| Service history | |
| In service | 1925–1975 |
| Used by | United States |
| Wars | World War II Korean War Vietnam War |
| Production history | |
| Variants | Mk 9, Mk 12, Mk 14, Mk 15, Mk 16 |
| Specifications | |
| Barrel length | 440 inches (11 m) bore (55 caliber) |
| Shell | 335 pounds (152 kg)[1]A.P. 260 pounds (118 kg)[2] H.E. |
| Caliber | 8 inches (20 cm) |
| Muzzle velocity | 2,500 feet per second (760 m/s)[1] |
| Maximum firing range | 30,050 yards (27,480 m)[1] |
,_USS_Pensacola_(CA-24)_and_USS_New_Orleans_(CA-32)_at_Pearl_Harbor_on_31_October_1943.jpg)
The 8"/55 caliber gun (spoken "eight-inch-fifty-five-caliber") formed the main battery of United States Navy heavy cruisers and two early aircraft carriers. United States naval gun terminology indicates the gun barrel had an internal diameter of 8 inches (203 mm), and the barrel was 55 calibers long (barrel length is 8 inch × 55 = 440 inches or 36.6 feet or 11 meters).[3]