6"/53 caliber gun

6"/53 caliber naval gun
Type	Naval gun
Service history
In service	1920 - 1945
Used by	United States
Wars	World War II
Production history
Variants	Mk 13, Mk 16, Mk 17
Specifications
Barrel length	8 meters (300 in) bore (53 calibers)
Shell	105 pounds (48 kg)
Caliber	150 millimeters (6 in)
Muzzle velocity	900 meters per second (3,000 ft/s)
Maximum range	23,130 meters (25,300 yd)

The 6"/53 caliber gun (spoken "six-inch-fifty-three-caliber") formed the main battery of United States Navy light cruisers and submarine cruisers built during the 1920s. United States naval gun terminology indicates the gun fired a projectile 6 inches (15 cm) in diameter, and the barrel was 53 calibers long (barrel length is 6 inch x 53 = 318 inches or 8 meters.) The gun with side swing Welin breech block and Smith-Asbury mechanism weighed about 10 tonnes and used a silk bag containing 44-pounds (20 kg) of smokeless powder to give a 105-pound (47.6 kg) projectile a velocity of 3000 feet per second (900 m/s). Early Marks were built-up guns with a liner, tube, full-length jacket, and 2 hoops; but the Mark 14 gun was of monobloc construction. Useful life expectancy was 700 effective full charges (EFC) per liner.

Mark 13 casemate mounting

These guns were intended for the secondary battery of the Lexington class battlecruisers and South Dakota class battleships. They were installed in Omaha class cruisers when the intended ships were canceled under provisions of the Washington Naval Treaty. Range was 11 miles (19 kilometers) at the maximum elevation of 20 degrees.

Mark 16 turret mounting

This two-gun turret was a design modification to improve the range and broadside of the Omaha class cruisers. Range was 13 miles (23 kilometers) at the maximum elevation of 30 degrees.

Mark 17 wet mounting

These single open mounts were installed fore and aft of the conning tower on USS Argonaut (SM-1), USS Narwhal (SS-167), and USS Nautilus (SS-168). Range was 12 miles (21 kilometers) at the maximum elevation of 25 degrees.

References

• Campbell, John (1985). Naval Weapons of World War Two. Naval Institute Press. ISBN 0-87021-459-4. 
• Fairfield, A.P. (1921). Naval Ordnance. The Lord Baltimore Press. 

Campbell 1985 pp.132-3

Fairfield 1921 p.156