| Ordnance QF 4-inch gun Mk I, II, III | |
| Origin: | United Kingdom |
| Type: | Naval gun Coast defence gun |
| Is Ranged: | yes |
| Is Artillery: | yes |
| Is Uk: | yes |
| Service: | 1896 - 1920[1] |
| Used By: | British Empire |
| Wars: | Boxer Rebellion, World War I |
| Design Date: | 1895 |
| Weight: | 2912lb barrel & breech |
| Part Length: | 160inches bore (40 cal); 165.35inches total |
| Cartridge: | Separate-loading QF 25lb Common pointed or Lyddite |
| Caliber: | 4sing=onNaNsing=on |
| Velocity: | 2300ft/s[2] |
| Max Range: | 9000yd[3] |
| Breech: | Single-motion screw |
The QF 4-inch gun Mks I, II, III[4] were early British QF (quick-firing) naval guns originating in 1895. They all had barrels of 40 calibres length.
The gun was intended to be a more powerful alternative to the quick-firing 3-inch QF 12-pounder gun, and a faster-firing replacement for the BL 4-inch gun.
It was mounted on the following ships :
Its 25lb shell proved insufficiently powerful to make it much of an improvement on the 12-pounder. From 1907 onwards it was succeeded in its class on new warships by the BL 4 inch gun Mk VIII, which fired a 31lb shell.
From 1906 a number of Mk III guns were transferred from the Royal Navy for use as coast defence guns around the United Kingdom, and remained until 1939.[5]
In 1918 three guns were in service at Dover Garrison and eight at Forth Garrison.[6]
On 20 September 1914 the British cruiser was sunk by in Zanzibar harbour. Her 8 QF 4-inch Mk III guns were recovered and used ashore in the East African campaign. Some were used as coast defence guns at Zanzibar and Mombasa. Two guns, and from 11 February 1916, three guns, were used by 10th Heavy Battery manned by the Royal Marines, mounted on improvised field carriages and towed by Packard lorries, supported by six REO lorries carrying ammunition.[7]