

A light weight gun for submarines. Developed too late for service during World War II.
Constructed with a monobloc loose barrel and breech ring. The bore and external parallel section were nickel plated and zinc protective plates were on the breech ring and horizontal sliding breech block. A total of thirty-one guns were manufactured. Actual bore length was 33.04 calibers.
| Designation | 4"/33 (10.2 cm) QF Mark XXIII |
|---|---|
| Ship Class Used On | A class and a few T class submarines |
| Date Of Design | about 1944 |
| Date In Service | 1946 |
| Gun Weight | 0.7 tons (0.76 mt) |
| Gun Length oa | 137.6 in (3.495 m) |
| Bore Length | 132.2 in (3.358 m) |
| Rifling Length | N/A |
| Grooves | N/A |
| Lands | N/A |
| Twist | N/A |
| Chamber Volume | 183 in3 (3.00 dm3) |
| Rate Of Fire | about 15 rounds per minute |
| Type | Fixed |
|---|---|
| Projectile Types and Weights | HE: 35 lbs. (15.9 kg) HE: 38.5 lbs. (17.5 kg) |
| Bursting Charge | N/A |
| Projectile Length | N/A |
| Propellant Charge | 3.75 lbs. (1.7 kg) NF052 3.88 lbs. (1.8 kg) NF052 |
| Muzzle Velocity | For 35 lbs. (15.9 kg): 1,791 fps (546 mps) For 38.5 lbs. (17.5 kg): 1,745 fps (532 mps) |
| Working Pressure | N/A |
| Approximate Barrel Life | N/A |
| Ammunition stowage per gun | N/A |
Data from:
- "British Naval Guns 1880-1945 No 18" article by John Campbell in "Warship Volume X"
Special help by Rod Butcher
- 22 October 2008
- Benchmark
- 12 February 2012
- Updated to latest template
- 29 November 2015
- Changed Vickers Photographic Archive links to point at Wayback Archive