3"/23 caliber gun

The 3"/23 caliber gun (spoken "three-inch-twenty-three-caliber") was the standard anti-aircraft gun for United States destroyers through World War I and the 1920s. United States naval gun terminology indicates the gun fired a projectile 3 inches (76 mm) in diameter, and the barrel was 23 calibers long (barrel length is 3" x 23 = 69" or 1.75 meters.)

Description
The built-up gun with vertical sliding breech block weighed about 531 pounds (241 kg) and used fixed ammunition (case and projectile handled as a single assembled unit) with a 13-pound (6 kg) projectile at a velocity of 1650 feet per second (500 m/s). Range was 10100 yards (9235 meters) at 45 degrees elevation. Ceiling was 18000 feet (5500 meters) at the maximum elevation of 75 degrees.

History
The 3"/23 caliber cannon was the US Navy's first purposefully, designed anti-aircraft cannon to reach operational service in the US military, and was a further development of 1 pounder cannon concept designed by Admiral Twining to meet the possible threat from airships being built by various navies. When World War II began, the 3"/23 caliber gun was outdated and surviving United States destroyers built during World War One era that were armed with 3"/23 caliber were rearmed with dual-purpose 3"/50 caliber guns during World War II. Where there was no air threat during World War Two, the 3"/23 caliber gun was employed in the surface to surface role for use against submarines, and was mounted on submarine chasers, armed yachts, and various auxiliaries. Some major warships carried 3"/23 caliber guns temporarily while awaiting installation of quad 1.1"/75 caliber guns.

The 3"/23 caliber gun was mounted on:
 * Caldwell class destroyers
 * Wickes class destroyers
 * Clemson class destroyers
 * Town class destroyers