3"/50 Caliber Gun - Cold War Anti-aircraft Gun

Cold War Anti-aircraft Gun

The 3"/50 caliber gun (Mark 22) was a semiautomatic anti-aircraft weapon with a power driven automatic loader. The United States Navy considered contemporary 5"/38 caliber guns and 5"/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 40 mm antiaircraft gun mount and the twin for a quadruple 40 mm mount. Although intended as a one-for-one replacement for the 40 mm mounts, the final version of the new 3-inch (76 mm) mounts was heavier than expected, and on most ships the mounts could be replaced only on a two-for-three basis. The mounts were of the dual purpose, open-base-ring type. The right and left gun assemblies were identical in the twin mounts. The mounts used a common power drive that could train at a rate of 30 degree/second and elevate from 15 degrees to 85 degrees at a rate of 24 degree/second. The cannon was fed from an on mount magazine which was replenished during action by two loaders on each side of the cannon.

With proximity fuze and fire-control radar, a dual 3"/50 mount firing 20 rounds per minute per barrel was considered more effective than a quad Bofors 40 mm gun against subsonic aircraft, but relatively ineffective against supersonic jets and cruise missiles. Destroyers that were modernized during the Fleet Rehabilitation and Modernization (FRAM) program of the 1960s had their 3-inch (76 mm) guns removed, but others retained them. In 1992, The USCGC Storis (WMEC-38) 3"/50 caliber main battery was removed from the cutter. It was the last 3"/50 caliber gun in service aboard any US warship. The gun is still in service, however, on select warships of the Philippine Navy.