Original Item. Only One Available. The 3-inch .50 caliber gun (spoken "three-inch-fifty-caliber") in United States naval gun terminology indicates the gun fired a projectile 3 inches (76mm) in diameter, and the barrel was 50 calibers long (barrel length is 3 in × 50 = 150 in or 3.8 m). Different guns (identified by Mark numbers) of this caliber were used by the U.S. Navy and U.S. Coast Guard from 1890 through the 1990s on a variety of combatant and transport ship classes.

Not Available for Export.

The US Navy's first 3-inch .50 cal gun (Mark 2) was an early model with a projectile velocity of 2,100 feet (640 m) per second. Low-angle mountings for this gun had a range of 7000 yards at the maximum elevation of 15 degrees. The gun entered service around 1902 with the Bainbridge-class destroyers and was also fitted to Connecticut-class battleships. By World War II, these guns had been found only on a few Coast Guard cutters and defensively equipped merchant ships. Low-angle 3?/50 caliber guns (Marks 3, 5, 6, and 19) were originally mounted on ships built from the early 1900s through the early 1920s and were carried by submarines, auxiliaries, and merchant ships during the Second World War. These guns fired the same 2,700 feet (820 m) per second ammunition used by the following dual-purpose Marks but with range limited by the maximum elevation of the mounting. These were built-up guns with a tube, partial-length jacket, hoop, and vertical sliding breech block.

Dual-purpose 3-inch .50 cal guns (Marks 10, 17, 18, and 20) first entered service in 1916 as a refit to USS Texas (BB-35) and were subsequently mounted on many types of ships as the need for anti-aircraft protection was recognized. During World War II, they were the primary gun armament on destroyer escorts, patrol frigates, submarine chasers, minesweepers, some fleet submarines, and other auxiliary vessels, and were a secondary dual-purpose gun on some other types of ships, including some older battleships. They also replaced the original low-angle 4-inch .50 caliber guns (Mark 9) on "flush-deck" Wickes and Clemson-class destroyers to provide better anti-aircraft protection. The AVD seaplane tender conversions received two guns; the APD transport, DM minelayer, and DMS minesweeper conversions received three guns, and those retaining destroyer classification received 6. These guns used fixed ammunition (case and projectile handled a single assembled unit) weighing 34 pounds. Projectiles weighed about 13 pounds, including a burster charge of 0.81 pounds for anti-aircraft (AA) rounds and 1.27 pounds for high capacity (HC) rounds. The maximum range was 14,600 yards at 45 degrees elevation, and the ceiling was 29,800 feet (9,100 m) at 85 degrees elevation. Useful life expectancy was 4300 effective full charges (EFC) per barrel. The 3-inch .50 cal gun (Mark 22) was a semiautomatic anti-aircraft weapon with a power-driven automatic loader. The United States Navy considered contemporary 5-inch .38 caliber guns and 5-inch .54 caliber guns more effective against surface targets. These monobloc 3? guns were fitted to both single and twin mountings. The single was to be exchanged for a twin 40mm antiaircraft gun mount and the twin for a quadruple 40mm mount. This was performed on Essex-class aircraft carriers, Sumner- and Gearing-class destroyers, and other ships circa 1946-50.

This is a good Post-WWII example with good paint and markings. The side of the projectile is marked:

ALN PK-29..  57
3” / 50 A.P. PROJ. MK 29-1 BDF M68A2

The round measures 34” tall with a 4 ¼” base diameter.

Ready to display.

Totally inert, cannot be converted to an explosive device, not available for export. This item is completely legal within the USA. International Military Antiques, Inc observes all Federal, State and Local laws. Everything for sale on ima-usa.com is completely legal to own, trade, transport and sell within the United States of America.

All deactivated ordnance sold by IMA, Inc is engineered to be inoperable according to guidelines provided by the US Bureau of Alcohol, Tobacco, Firearms and Explosives (BATF).