| BL 6-inch Mk XII naval gun | |
|---|---|
 Casemate gun on HMS Warspite after the Battle of Jutland, June 1916 | |
| Type | Naval gun |
| Place of origin | United Kingdom |
| Service history | |
| In service | 1914–2011 |
| Used by | British Empire |
| Wars | |
| Production history | |
| Designer | Vickers |
| Designed | 1913 |
| Manufacturer | Vickers |
| No. built | 463 |
| Specifications | |
| Mass | 15,512 pounds (7,036 kg) barrel & breech[1] |
| Barrel length | 270 inches (6.858 m) bore (45 cal)[2] |
| Shell | 100 pounds (45.36 kg) Lyddite, Armour-piercing, Shrapnel[3] |
| Calibre | 6 inches (152.4 mm) |
| Breech | Welin interrupted screw |
| Recoil | Hydro-spring, 16.5 inches (420 mm)[4] |
| Elevation | −7°–30°[5] |
| Rate of fire | 5-7 rpm |
| Muzzle velocity | 2,825 feet per second (861 m/s)[6] |
| Maximum firing range | 19,660 metres (21,500 yd)[7] |
The BL 6-inch Mark XII naval gun[8] was a British 45 calibre naval gun which was mounted as primary armament on light cruisers and secondary armament on dreadnought battleships commissioned in the period 1914–1926, and remained in service on many warships until the end of World War II.
- ^ Handbook, 1917, Page 5
- ^ Handbook, 1917, Page 7
- ^ 100 lb shells: Treatise on Ammunition, 1915
- ^ Handbook, 1917, Page 6, 23-26
- ^ 30° elevation was possible with P.XIII mountings used on light cruisers; 20° elevation was possible on some P.VII* mountings used on light cruisers; 14° elevation was possible with P.IX mountings used on battleships; 15° was possible with P.VII mountings used on light cruisers. Handbook, 1917, Pages 5, 31, 41, Plates 6, 24, 35
- ^ 2,825 feet per second using 27 lb 2 oz cordite MD size 19 propellant was the figure used in range tables. New guns were quoted with a muzzle velocity of 2,845 feet per second. Handbook, 1917, Page 5
- ^ "Gun Model: BR 6in 45cal BL Mk XII". navalhistory. Retrieved 6 September 2014.
- ^ Mark XII = Mark 12 : Britain denoted Marks (models) of guns with Roman numerals until after World War II. This was the twelfth model of British BL 6-inch gun.