M24 20 mm autocannon

M24 20 mm autocannon was an American-built derivative of the Hispano-Suiza HS.404 aircraft cannon, developed during the latter stages of World War II. Designed to provide a reliable, belt-fed 20 mm caliber weapon for United States Army Air Forces aircraft, it saw limited combat service before becoming more widely used in the early Cold War period. The weapon was employed in several notable aircraft and was part of the transition from machine gun-based armaments to heavier cannon armament in American fighter design.

Development and design

The development of the M24 was driven by the United States Army Air Forces' need for a more reliable, belt-fed version of the Hispano-Suiza HS.404, which had been license-produced as the M2 cannon and M3 cannon. These earlier models, used in aircraft like the P-38 Lightning and P-61 Black Widow, were often hampered by feed mechanism issues. Engineers at the American Armament Corporation, under contract from the War Department, modified the Hispano-Suiza design to utilize a disintegrating link belt feed system, improving reliability. The project received impetus from the War Production Board and was influenced by combat reports from theaters like the European Theater of Operations and the Pacific War.

Operational history

The M24 entered service too late to see extensive use in World War II, with its first operational deployment occurring in 1944. It was primarily fitted to the P-80 Shooting Star, the United States Air Force's first operational jet fighter, which entered service just after the war. During the Korean War, the M24 was the standard cannon armament for the F-86 Sabre and saw significant action in air-to-air combat against Mikoyan-Gurevich MiG-15s over MiG Alley. Its performance in these engagements, part of the larger Cold War confrontation, helped validate the shift to cannon-based armament for jet aircraft, though it was eventually superseded by newer designs like the M39 cannon.

Variants

The primary variant was the standard M24, as described. A derivative, the M24A1, featured minor improvements to the feed mechanism and bolt assembly for increased rate of fire. These modifications were tested at facilities like Eglin Air Force Base and the Aberdeen Proving Ground. The basic design also influenced later American aircraft cannon development, including the M61 Vulcan rotary cannon produced by General Electric.

Specifications

* **Caliber:** 20 mm (20x110mm cartridge) * **Operation:** Short recoil * **Feed System:** Disintegrating link belt * **Rate of Fire:** 600–750 rounds per minute * **Muzzle Velocity:** 2,800 ft/s (853 m/s) * **Weight:** 110 lb (50 kg) * **Length:** 7.5 ft (2.29 m) * **Barrel Length:** 70 in (1.78 m)

Users

The primary user was the United States, through the United States Army Air Forces and its successor, the United States Air Force. It was also supplied to several NATO allies under programs like the Mutual Defense Assistance Act, including the Royal Canadian Air Force and the Japan Air Self-Defense Force. The Republic of China Air Force used the cannon on its F-86 Sabre aircraft, and it saw service with the Republic of Korea Air Force during the Korean War.

Category:Autocannon Category:World War II American aircraft weapons Category:Cold War aircraft weapons