Britain
12"/50 (30.5 cm) Mark XIV
Updated 18 August 2013
 This was an experimental weapon developed in the early 1930s to test "all-steel" construction techniques.  It was the first British heavy gun to be designed for a cast steel cylindrical cradle.  This design would probably have been used on new British battleships if Naval Limitation Treaties of the 1930s had limited gun caliber to 12 inches (30.5 cm).

The Mark XIV was used as a basis for the 14" (35.6 cm) Mark VII guns used on the King George V battleships and the 16" (40.6 cm) Mark II guns for the planned Lion class battleships.

Constructed of tapered inner A tube, A tube, jacket, breech ring with breech bush and shrunk collar.  Used a Welin breech block with Asbury breech mechanism.
.
Gun Characteristics
.
Designation 12"/50 (30.5 cm) Mark XIV
Ship Class Used On Experimental Gun
Date Of Design 1930
Date In Service 1933 (as experimental gun)
Gun Weight 50.5 tons (51.3 mt)
Gun Length oa 618 in (14.697 m)
Bore Length 600 in (15.240 cm)
Rifling Length N/A
Grooves N/A
Lands N/A
Twist N/A
Chamber Volume 14,583 in3 (239 dm3)
Rate Of Fire about 2 rounds per minute
.
Ammunition
.
Type Bag
Projectile Types and Weights APC - 950 lbs. (430.9 kg)
Bursting Charge N/A
Projectile Length N/A
Propellant Charge
(see Note 2)		 226 lbs. (102.5 kg) SC280
Muzzle Velocity 2,652 fps (808 mps)
Working Pressure N/A
Approximate Barrel Life N/A
Ammunition stowage per gun N/A (probably about 100 rounds)
Note:  Trial shells were 6/[infinity] crh.
.
Range
.
Elevation With 950 lbs. (430.9 kg) AP Shell
Range @ 40 degrees about 37,000 yards (33,830 m)
.
Mount / Turret Data
.
Designation Two and Three-gun Mountings
Weight N/A
Elevation -5 / +40 degrees
Rate of Elevation N/A
Train About -150 / +150 degrees
Rate of Train N/A
Gun Recoil N/A
Loading Angle +5 degrees
Note:  During the late 1920s preliminary estimates were drawn up for ships armed with eight or nine 12 inch (30.5 cm) guns.  Detailed plans for a three-gun turret were drawn up by Vickers-Armstrong in the early 1930s but none were ordered.
.
Data from
"Nelson to Vanguard:  Warship Design and Development 1923-1945" by D.K. Brown
"British Naval Guns 1880-1945 No 4" article in "Warship Volume V" by John Campbell
"British Battleships of World War Two" by Alan Raven and John Roberts
Page History

20 February 2009 - New datapage
18 August 2013 - Corrected typographical error