Military Wiki
Ordnance QF 4 inch gun Mk IV, XII, XXII
QF 4 inch Mk IV gun IWM.jpg
Mk IV gun from HMS Lance at the Imperial War Museum, London
Type Light Naval gun
Submarine gun
Place of origin United Kingdom
Service history
In service 1911-1940s
Used by  United Kingdom
Wars World War I
World War II
Weight 2,750 pounds (1,250 kg) barrel & breech
Barrel length 160 inches (4.064 m) bore (40 calibres)

Shell Mk IV : Separate QF 31 pounds (14.06 kg);
Mk XII & XXII : Fixed QF 31 pounds (14.06 kg), 35 pounds (15.88 kg) from 1944[1]
Calibre 4-inch (101.6 mm)
Breech horizontal sliding block
Muzzle velocity Mk IV : 2,370 feet per second (720 m/s)[2]
Mk XII & XXII : 1,873 feet per second (571 m/s)
Maximum range 10,000 yards (9,100 m)

The QF 4-inch gun Mk IV[3] was introduced in 1911 as a faster-loading light gun successor to the BL 4 inch Mk VIII gun, and was the main gun on most Royal Navy and British Empire destroyers in World War I.

Mk IV gun

On R class destroyer HMS Satyr circa. 1917 - 1918

Gun recoiling after firing, on Australian auxiliary anti-submarine vessel HMAS Wilcannia ca. 1943

Mk IV armed many British destroyers and some cruisers in World War I. It was used to arm merchant ships in World War II.

The guns armed the following warships :

Mk XII and XXII submarine gun

Mk XII gun on unidentified T class submarine circa. WWII

The Mk XII variant was developed for arming submarines from 1918, Mk XXII was developed to arm submarines during World War II. These submarine guns fired a heavier 35-pound projectile from late 1944.[1] Mk XII and XXII equipped :

Surviving guns

See also

Weapons of comparable role, performance and era


  1. 1.0 1.1 DiGiulian
  2. 2,370 ft/s for Mk IV gun with 31 lb (14 kg) projectile in WWI, using 5 lb 1 oz 12 drams cordite MD size 16 propellant (Treatise on Ammunition, 10th Edition 1915)
  3. Mk IV = Mark 4. Britain used Roman numerals to denote Marks (models) of ordnance until after World War II. This was the fourth model of 4-inch QF naval gun. Variants Mk XII = Mark 12, Mk XXII = Mark 22.


External links

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