BL 8-inch Mk I – VII naval gun
| Ordnance BL 8 inch gun Mks I - VII | |
|---|---|
| Type | Naval gun Coast defence gun |
| Place of origin | United Kingdom |
| Service history | |
| In service | 1884 - 190? |
| Used by | United Kingdom Colonial navies of Australia New Zealand Singapore |
| Production history | |
| Designer | Mk I, VI : RGF Mk VII : EOC |
| Manufacturer | Mk I, III, IV : RGF Mk III, IV, VI, VII EOC |
| Unit cost | £6,015 |
| Variants | Mks III, IV, VI, VII, VIIA |
| Specifications | |
| Mass | Mk III & VI : 14 tons Mk IV : 15 tons Mk VII : 12 tons Mk VIIA : 13 tons barrel & breech |
| Barrel length | Mk III : 201 inches (5,105 mm) Mk VII : 204 inches (5,182 mm) Mk IV & VI : 237 inches (6,020 mm) bore |
| Shell | Mks III, IV, VI : 210 pounds (95.25 kg) Mk VII : 180 pounds (81.65 kg) |
| Calibre | 8-inch (203.2 mm) |
| Muzzle velocity | Mk III : 1,953 feet per second (595 m/s) Mk IV & VI : 2,150 feet per second (655 m/s) Mk VII : 2,000 feet per second (610 m/s) |
| Maximum firing range | 8,000 yards (7,300 m) |
The BL 8 inch guns Mark I to Mark VII were the first generations of British rifled breechloaders of medium-heavy calibre. They were initially designed for gunpowder propellants and were of both 25.5 and 30 calibres lengths.