BL 6 inch Mk XXII naval gun

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Ordnance QF 6 inch gun Mk XXII
HMS Rodney 6 inch gun turrets IWM A 95.jpg
Gun turrets on HMS Rodney, 1940
Type Naval gun
Service history
In service 1927 - 1947
Used by United Kingdom
Wars World War II
Production history
Designed 1921
No. built 40
Variants Mark XXII*
Specifications
Weight 19,824 lbs. (8,992 kg)
Barrel length 300 inches (7.620 m) bore (50 calibres)

Shell 1927 : 100 pounds (45 kg)
1942 : 112 pounds (51 kg)[1]
Calibre 6-inch (152.4 mm)
Breech 364 lbs. (165.1 kg) Welin interrupted screw
Recoil 16.5 in (42 cm)
Elevation -5 / +60 degrees
Traverse +100 / -100 degrees
Rate of fire 5 rpm
Muzzle velocity 898 metres per second (2,950 ft/s)[1]

The BL 6-inch Mk XXII gun[note 1] was a British high-velocity 6-inch 50-calibre wire-wound naval guns deployed on the Nelson-class battleships from the 1920s to 1945.

Backround[edit]

They were originally designed as secondary armament for the proposed G3 class battlecruisers. When the G3 class were cancelled after the Washington Naval Treaty the guns and mountings were later used as secondary armament on the two Nelson-class battleships, serving throughout World War II. The Nelsons were the first British battleships since the Lord Nelson class of 1904 to carry their secondary armament in turrets rather than in broadside casemates. The Mk VIII gun mountings could elevate from +60 degrees to -5 degrees, while the telescopic power rammers for the gun loaded at a +5 degree fixed angle.[2] Although classified as a dual-purpose gun and capable of high-angle fire their training and elevation speeds were too slow for the anti-aircraft role and their main use was against surface targets.

Ammunition[edit]

The gun originally fired a 100-pound (45 kg) shell, which had been the standard shell weight for six-inch guns since 1880. From 1942 the gun fired the same 112-pound (51 kg) shell introduced for the later Mk XXIII gun.[3] Figures in the table below are for the 100lb shell.

Shell trajectory[edit]

Range[4] Elevation Time of flight Descent Impact velocity
5000 yd (4.6 km) 2° 5.2′ 6.20 sec 2° 48′ 2029 ft/s (618 m/s)
10000 yd (9.1 km) 5° 37.2′ 15.22 sec 9° 13′ 1390 ft/s (424 m/s)
15000 yd (14 km) 12° 5.4′ 28.55 sec 23° 2′ 1094 ft/s (333 m/s)
20000 yd (18 km) 22° 54′ 46.14 sec 39° 46′ 1056 ft/s (322 m/s)
25000 yd (22.86 km) 42° 37′ 74.92 sec 59° 0′ 1148 ft/s (350 m/s)

See also[edit]

Weapons of comparable role, performance and era[edit]

Notes[edit]

  1. ^ MK XXII = Mark 22. Britain used Roman numerals to denote Marks (models) of ordnance until after World War II. This was the twenty-second model of British BL 6-inch gun

References[edit]

  1. ^ a b http://navalhistory.flixco.info/H/65069x53535/8330/a0.htm
  2. ^ Campbell, Naval Weapons of WWII, p.37.
  3. ^ DiGiulian
  4. ^ Campbell, Naval Weapons of WWII, p.37.

Bibliography[edit]

  • Campbell, John (1985). Naval Weapons of World War Two. Naval Institute Press. ISBN 0-87021-459-4. 

External links[edit]