5-inch/25-caliber gun
| 5"/25 Caliber Gun | |
|---|---|
On the deck of Balao-class submarine USS Bowfin | |
| Type | Anti-aircraft gun Naval gun |
| Place of origin | United States |
| Service history | |
| Used by | US Navy, Argentine Navy |
| Wars | World War II, Falklands War |
| Production history | |
| Variants | Mk 10, 11, 13, 17 |
| Specifications | |
| Mass | 2 metric tons |
| Length | 11 ft 10 in (3.6 m) |
| Barrel length | 10 ft 5 in (3,175 mm) bore (25 calibers) 8 ft 2 in (2.4 m) rifling |
| Shell | 127 × 626 mm R fixed or semi-fixed 52 to 54.5 lb (23.6 to 24.7 kg) |
| Caliber | 5 in (127 mm) |
| Elevation | -10° to +85° |
| Muzzle velocity | 2,100 ft/s (640 m/s) average |
| Effective firing range | 14,500 yards (13,300 m) at 40° 27,400 feet (8,400 m) at 85° |
The 5"/25 caliber gun (spoken "five-inch-twenty-five-caliber") entered service as the standard heavy anti-aircraft (AA) gun for United States Washington Naval Treaty cruisers commissioned in the 1920s and 1930s. The goal of the 5"/25 design was to produce a heavy AA gun that was light enough to be rapidly trained manually. The gun was also mounted on pre-World War II battleships and aircraft carriers until replaced by the standard widespread dual-purpose 5"/38 caliber gun, which was derived from the 5"/25. Guns removed from battleships were probably converted for submarine use by late 1943, while a purpose-built variant for submarines was available in mid-1944, and was widely used by them. United States naval gun terminology indicates the gun fired a projectile 5 inches (127 mm) in diameter, and the barrel was 25 calibers long (that is, for a 5" bore and a barrel length of 25 calibers, 5" x 25 = 125", or about 3.2 meters). It is referred to sometimes as a dual-purpose gun and sometimes as an anti-aircraft gun, because of its comparative weakness against surface targets.