The Army's First Anti-Aircraft Gun M2A1

[Monthly Defense Times Editor-in-Chief An Seung-beom] The M2A1 40mm anti-aircraft gun, the first anti-aircraft artillery operated by our military, has long been retired, but it was a classic old anti-aircraft gun that served as our military's first low-altitude air defense weapon system.

The operation method of the M2A1 40mm anti-aircraft gun can be seen in the gunner's seat. The crew consists of four members, with two positioned in the gunner's seat and two ammunition handlers located on the sides. As shown in the photo, the gunner aims at the target visually using a ring sight and manually adjusts the elevation and traverse by turning the handwheel, so the targets it could engage were limited to slow propeller aircraft.

The firing rate is specified as 120 rounds per minute, but in actual firing, the ammunition handlers manually reload 5-round clips one by one, so the real firing rate is lower.

The M2A1 anti-aircraft gun is a ground-towed version of the Swedish Bofors 40mm autocannon developed by the United States after World War I. Our military acquired it from the U.S. in 1949 and reportedly operated it during the Korean War, but large-scale formal operation began in 1955.

Until the KM167A1 20mm towed Vulcan cannon was fully introduced after 1976, the M2A1 40mm, along with the quad-barrel 50-caliber heavy machine gun Seungjeonpo, was the main anti-aircraft artillery and was deployed and operated at key air defense positions.

Even after the introduction of the Vulcan cannon and portable anti-aircraft missiles, it is known to have been operated at rear coastal positions until the late 2000s.

The M2A1 anti-aircraft gun features a 16-groove rifled barrel, a firing rate of 120 rounds per minute, and an effective range of 1.65 km for anti-aircraft and 1.85 km for ground targets.

Like almost all anti-aircraft guns, it was capable of ground fire as well and was used during the Korean War to attack enemy troops and positions.

Although this anti-aircraft gun is now retired and considered old, it served as the design basis for Nobong, the first domestically developed naval gun, and an improved version of Nobong was adopted as the main gun for Hanwha Defense's K21 infantry fighting vehicle.