QF 4-inch naval gun Mk XXIII
| Ordnance QF 4 inch gun Mk XXIII | |
|---|---|
| Type | Submarine deck gun |
| Place of origin | United Kingdom |
| Service history | |
| In service | 1945-1974 |
| Used by | United Kingdom |
| Wars | Indonesia–Malaysia confrontation Cold War |
| Production history | |
| Produced | 1945-46 |
| No. built | 31 |
| Specifications | |
| Mass | 1,568 lb (711 kg) barrel and breech |
| Length | 137.6 in (3.495 m) |
| Barrel length | 132.2 in (3.358 m) bore (33 calibres) |
| Shell | Fixed QF 35 lb (15.9 kg) 38.5 lb (17.5 kg) |
| Calibre | 4 in (102 mm) |
| Breech | horizontal sliding-block |
| Carriage | 4-0 Inch SII Mounting |
| Elevation | -10 to +30 degrees |
| Traverse | 360 degrees |
| Rate of fire | about 15 rounds per minute |
| Muzzle velocity | 35 lb: 1,791 ft/s (546 m/s) 38.5 lb: 1,745 ft/s (532 m/s) |
| Maximum firing range | 12,080 yd (11.05 km) 35 lb HE shell at 30 degrees: |
The QF 4-inch gun Mark XXIII was introduced in late 1945 as a deck gun for Royal Navy submarines. It was the last type of gun to be fitted to British submarines, finally being retired in 1974.