BL 6-inch Mk XXIII naval gun
| Ordnance BL 6 inch gun Mk XXIII | |
|---|---|
Forward triple-gun turrets of HMS Belfast, March 2005  | |
| Type | Naval gun | 
| Place of origin | United Kingdom | 
| Service history | |
| In service | 1931–1985 | 
| Used by |  Royal Navy Royal Australian Navy Royal New Zealand Navy Royal Canadian Navy Indian Navy Peruvian Navy Republic of China Navy People's Liberation Army Navy  | 
| Wars | Second World War Korean War  | 
| Production history | |
| No. built | 469 | 
| Specifications | |
| Mass | 7 tonnes | 
| Barrel length | 300 inches (7.6 meters) | 
| Shell | 112 pounds (51 kg) | 
| Calibre | 6-inch (152.4 mm) | 
| Muzzle velocity | 2760 feet per second (840 m/s) | 
| Maximum firing range | 25,480 yd (23,300 m) at 45 degrees elevation | 
The 50-calibre BL 6-inch gun Mark XXIII was the main battery gun used on the Royal Navy and British Commonwealth's conventional (non-anti-aircraft) light cruisers built from 1930 through the Second World War, and passed into service with several other navies when ships were disposed of after the end of the War.