| BL 6-inch Mk XI naval gun | |
|---|---|
 Gunnery exercise on HMAS Melbourne circa. 1913 | |
| Type | Naval gun Coast defence gun |
| Place of origin | United Kingdom |
| Service history | |
| In service | 1906 – 1957 |
| Wars | World War I World War II |
| Production history | |
| No. built | 177[1] |
| Variants | Mk XI |
| Specifications | |
| Mass | 19,237 lbs (8,726 kg)[2] |
| Barrel length | 300 inches (7.620 m) bore (50 cal) |
| Shell | 100 pounds (45.36 kg) Lyddite, Armour-piercing, Shrapnel[3] |
| Calibre | 6 inches (152.4 mm) |
| Muzzle velocity | 2,900 feet per second (884 m/s)[4] |
| Maximum firing range | 18,000 yards (16,000 m) @ 22.5°[5] |
The BL 6-inch Mark XI naval gun[6] was a British 50 calibres high-velocity naval gun which was mounted as primary armament on cruisers and secondary armament on pre-dreadnought battleships from 1906 onwards.
- ^ Campbell, Naval Weapons of WWII, p.38.
- ^ Campbell, Naval Weapons of WWII, p.38.
- ^ 100 lb shells : Treatise on Ammunition, 1915
- ^ 2900 ft/second : As quoted in "Range Tables for His Majesty's Fleet, 1910. February, 1911"; with 32 lb 1½ oz cordite MD size 26 propellant : Treatise on Ammunition, 1915
- ^ 18,000 yards @ 22.5° elevation as coast defence gun, quoted by Spethman, 2008. Guns in naval use had lower elevation and hence shorter range.
- ^ Mk XI = Mark 11, i.e. the eleventh model of BL 6-inch guns. Britain used Roman numerals to denote Marks (models) of ordnance until after World War II.