BL 12-inch Mk X naval gun
| BL 12-inch gun Mk X | |
|---|---|
| Type | Naval gun |
| Place of origin | United Kingdom |
| Service history | |
| In service | 1906 – 1923 |
| Wars | World War I |
| Production history | |
| Designer | Vickers |
| Manufacturer | Vickers |
| Unit cost | £9800 (1907) |
| Specifications | |
| Mass | 57 tons barrel & breech |
| Barrel length | 45 feet (13.72 m) bore (45 cal) |
| Shell | 850 pounds (385.6 kg) Lyddite, Armour-piercing, Shrapnel |
| Calibre | 12 inches (304.8 mm) |
| Breech | Welin interrupted screw |
| Muzzle velocity | 2,700 ft/s (823 m/s) |
| Maximum firing range | 22,860 m (25,000 yd) |
The BL 12 inch Gun Mark X was a British 45-calibre naval gun which was mounted as primary armament on battleships and battlecruisers from 1906. It first appeared on HMS Dreadnought.