Type Naval gun In service 1880s - 190? Shell 25 pounds (11.34 kg) | Place of origin United Kingdom Used by United Kingdom | |
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The BL 4-inch gun Mk I - Mk VI were a family of early British breech-loading 4-inch naval guns.
Contents
13 cwt Mk I, 15 calibres
This was the first 4-inch BL gun. With its short (60-inch total) barrel it had a range of only 5,500 yards.
22.5 cwt Mk I, 25 calibres
With its longer barrel (100 inch bore) Mk I had a range of 7,200 yards. Both early Mk I types were quickly withdrawn from service following the explosion of a similar BL 6 inch Mk II gun on board HMS Cordelia in June 1891. Mk I 22.5 cwt continued to be used for training.
26 cwt Mks II - VI, 27 calibres
The improved 27-calibre Mk II gun and subsequent Marks, often referred to as 4 inch 26 cwt, replaced the early Mk I versions in service. The longer barrel (108 inch bore : 27 calibres) gave it a range of 7,700 yards.
Mk II guns and later Marks armed the following warships :
The gun was succeeded in its class from 1895 by the QF 4 inch gun Mk I.
QFC 4 inch gun
A small number of these guns were converted to QF to use the same cartridges as the QF 4 in gun. They were designated Mk I/IV, I/VI etc. depending on which Mark of BL 4-inch had been converted. All had a bore of 27.85 calibres after conversion, with a muzzle velocity of 2,177 ft/second.