QF 4 inch naval gun Mk IV, XII, XXII

Ordnance QF 4 inch gun Mk IV, XII, XXII
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
Specifications
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.

1 Mk IV gun
2 Mk XII and XXII submarine gun
3 Surviving guns
4 See also
5 Notes
6 References
7 External links

Mk IV gun

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 :

Forward class scout cruisers as re-gunned in 1911
Sentinel class scout cruisers as re-gunned 1911-1912
Pathfinder class scout cruisers as re-gunned 1911-1912
Adventure class scout cruisers as re-gunned 1911-1912
Acasta (K) class destroyers of 1911
Laforey (L) class destroyers of 1913
Yarrow M class destroyers laid down 1912 - 1915
Admiralty M class destroyer of 1913
Thornycroft M class destroyers laid down 1913 - 1915
Hawthorn M class destroyer of 1914
Talisman class destroyers of 1914
Medea class destroyers of 1914
Faulknor class leaders of 1914
Marksman class destroyers of 1914
Parker class leaders of 1915
Yarrow Later M class destroyers of 1915
R class destroyers of 1916
S class destroyers of 1917
Fundy class minesweepers of 1938 (guns from decommissioned Canadian S class destroyers)

Mk XII and XXII submarine gun

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

The Mk IV gun from HMS Lance which fired the first British shot of World War I on 5 August 1914 is on display at the Imperial War Museum, London.
An unrestored gun near Stanley, Falkland Islands

Notes

^ ^a ^b DiGiulian
^ 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)
^ 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.

References

Tony DiGiulian, British 4"/40 (10.2 cm) QF Marks IV, XII and XXII

External links

British Empire Naval weapons of the First World War

Monitor guns	BL 9.2 inch Mk VI · BL 9.2 inch Mk VIII · BL 9.2 inch Mk X · BL 9.2 inch Mk XII · BL 12 inch Mk VIII · US 14 inch 45 cal · BL 18 inch Mk I

Capital ship main armament	Vickers 10 inch 45 cal · EOC 10 inch 45 cal · BL 12 inch Mk VIII · BL 12 inch Mk IX · BL 12 inch Mk X · BL 12 inch Mk XI & XII · EOC 12 inch 45 cal Mk XIII · BL 13.5 inch Mk V · EOC 14 inch 45 cal Mk I · BL 15 inch Mk I

Armoured cruiser main armament	BL 7.5 inch Mk I · BL 9.2 inch Mk X · BL 9.2 inch Mk XI

Secondary armament & light cruiser main armament	QF 12 pdr 18 cwt · QF 14 pounder · QF 4 inch Mk III · BL 4 inch Mk VII · QF 4 inch Mk V · BL 4 inch Mk IX · BL 5.5 inch Mk I · QF 6 inch · BL 6 inch Mk VII · BL 6 inch Mk XI · BL 6 inch Mk XII · BL 6 inch Mk XIII-XVIII · BL 7.5 inch Mk II - Mk V

Destroyer & small cruiser armament	QF 12 pdr 12 cwt Mk II · QF 4 inch Mk III · BL 4 inch Mk VIII · QF 4 inch Mk IV · BL 4.7 inch Mk I

Merchant ship armament	QF 4.7 inch Mk I - IV · QF 4.7 inch Mk V*

Submarine guns	BL 4 inch Mk XI · QF 4 inch Mk XII

Anti-aircraft guns	QF 2 pounder "pom-pom" Mk II · QF 3 inch 20 cwt · QF 4 inch Mk V

Light weapons	.303 Vickers machine gun · QF 3 pounder Hotchkiss · QF 3 pounder Vickers · QF 6 pounder Hotchkiss

Torpedoes	18 inch Mk V - VIII · 21 inch Mk II · 21 inch Mk IV

Mines	Spherical Mk I, II and III · Vickers Elia mine · Type H mine

Anti-submarine weapons	Type D Depth charge · 7.5 inch howitzer

Landing guns	QF 12 pounder 8 cwt

British Commonwealth Naval weapons of the Second World War

Monitor guns	BL 15 inch

Capital ship main armament	BL 14 inch · BL 15 inch · BL 16 inch

Heavy cruiser main armament	BL 7.5 inch Mk VI · BL 8 inch Mk VIII

Secondary armament & light cruiser main armament	QF 4 inch Mk V · QF 4.5 inch · QF 5.25 inch · BL 6 inch Mk XII · BL 6 inch Mk XXII · BL 6 inch Mk XXIII

Minesweeper, Sloop, Corvette, Frigate & Destroyer armament	QF 6 pounder 10 cwt · QF 12 pdr 12 cwt Mk V · QF 4 inch Mk IV · BL 4 inch Mk IX · QF 4 inch Mk XIX · QF 4.5 inch · BL 4.7 inch Mk II · QF 4.7 inch Mk IX & XII · QF 4.7 inch Mk XI

Submarine guns	QF 12 pdr 12 cwt Mk V · QF 3 inch 20 cwt · QF 4 inch Mk XII & XXII

Anti-aircraft weapons	Unrotated Projectile · Holman Projector · 20 mm Oerlikon · QF 2 pounder "pom-pom" Mk VIII · 40 mm Bofors · QF 3 inch 20 cwt · QF 4 inch Mk V · QF 4 inch Mk XVI · QF 4.5 inch · QF 4.7 inch Mk VIII

Light weapons	.303 Lewis machine gun · .50 Vickers Mk III machine gun · QF 3 pounder Vickers

Torpedoes	21 inch Mk VII · 21 inch Mk VIII · 21 inch Mk X · 21 inch Mk XI · 24.5 inch Mk I

Mines

Anti-submarine weapons	Thornycroft depth charge thrower · Hedgehog · Squid

Small craft armament	Molins 6 pounder · Vickers K machine gun · 18 inch torpedo

Foreign-sourced weapons	3-inch 23 caliber gun (US) · 3-inch 50 caliber gun (US) · 4-inch 50 caliber Mark 9 gun (US) · 5-inch 51 caliber Mark 8 gun (US) · Y gun depth charge projector (US)