5"-38 caliber gun

Due to technical limitations, this article uses an unusual title. It should be called  5"/38 caliber gun.

5"/38 caliber open mount gun aboard the USS Shaw (DD-373) in 1942. This is a MK12 unit or very similar.

The 5"/38 caliber gun was mounted on a very large number of U.S. Navy ships in the World War II era. It was a dual-purpose gun (DP), effective for both anti-surface and anti-air warfare. The gun continued to be used into the 1970's, but has disappeared from service today. The barrel of a 5"/38 caliber gun has a five inch (127 mm) bore and a length 38 times the bore diameter, or 190 inches (15.83 ft. or 4.826 m) long.

Performance

The 5"/38 could project a 55 pound (25 kg) projectile for ranges up to 18,200 yards (16.6 km). In its antiaircraft role, it had a ceiling of 37,200 feet (11,300 m) at 85 degrees elevation. Millions of rounds of ammunition were produced for these guns, with over 720,000 rounds still remaining in Navy storage depots in the mid-1980s. The load consisted of a powder charge in a brass or low-alloy steel casing and a separate projectile. Many types of projectile were available, including AA Common, semi-armor piercing, proximity fuze/variable time (VT) fragmenting and high explosive (HE), point- and base detonating HE, white phosphorus and illuminating star shell.

Gun mounts

USMC crewed 5"/38 caliber dual gun mount aboard the USS New Jersey (BB-62), 1984.

There were several models of the 5"/38, differentiated by the word Mark (or its abbreviation MK) and a number. The 5"/38 MK 12 was a single-barrel open unit widely used on amphibious ships, auxiliaries, and merchant ships. The 5"/38 MK 30 was a single-barrel enclosed unit widely used on destroyers. The 5"/38 MK 38 was a dual enclosed unit specifically designed for newer destroyers. All of these models were also used on aircraft carriers, battleships, and other large combatants.

5 Inch/38 Caliber Gun Mounts

Mark	Barrels	Design	Use
12	1	Open	Amphibious ships, Auxiliaries, Merchant Ships
28	2	Enclosed	Battleships
30	1	Enclosed	Destroyers
32	2	Enclosed	Cruisers
38	2	Enclosed	Destroyers

Gun crews

Depending on the mount, a 5"/38 caliber gun could have a crew of up to 14 personnel, nine in the gun mount and 5 in the handling room. In US service, most gun crews were US Navy personnel. Even the civilian Merchant Marine ships had a small detachment of the Navy Armed Guard on board to operate the 5"/38 and other guns. One exception to this was on ships with a Marine Detachment, where the Marines manned one of the mounts, usually decorated with the Marine emblem.

See also

• Naval artillery
• Naval gunfire