One of the most numerous of the M2 Browning machine gun has been the M2 HB (Heavy Barrel). The HB version can be used in all manner of installations and in the past has been employed as an infantry gun, as an anti-aircraft gun and even as a fixed or trainable aircraft gun. For infantry use the M2 HB is usually mounted on a heavy tripod, but it can also be used mounted on vehicle pintles, ring mountings and pivots. Other M2 types include versions with water-cooled barrels, which were usually used as anti-aircraft weapons, especially on US Navy vessels where, during World War II, they were often fixed in multiple mountings for use against low-flying attack aircraft. Single water-cooled mountings were often used to provide anti-aircraft defense for shore installations. The main change between ground-based and aircraft versions was that the aircraft model had a barrel 914mm (36 in) long whereas the ground version had a barrel 1143 mm (45 in) long. Apart from the barrel and some mounting fixtures, any part of the M1921 and M2 machine-guns can be interchanged.

More .50 (12.7mm) Browning machine guns have been produced in the United States than any other design. To date the figures run into millions and the production run is still not complete, for during the late 1970s two American companies found it worthwhile to put the type back into production, and the same applied to the Belgian FN concern. Many more companies throughout the world find it profitable to provide spares and other such backing for the M2 series, and almost every year another ammunition producer introduces yet another type of cartridge for use with the weapon. Many dealers find it profitable just to sell or purchase such weapons alone, so there is no sign yet that demand for the gun is weakening in any way. The M2 has been around for many decades as it has been used in many armed conflicts around the world, and there is no sign of any replacement. It ranks as one of the most, if not the most, successful heavy machine gun ever produced.

Specifications (M2 HB)

Early operations by Defiant fighter aircraft at night were carried out without the benefit of AI radar, the aircraft simply being day fighters flown at night in conjunction with searchlights. The first Defiant squadron formed specifically for night fighting was No. 307, staffed by Polish pilots with the RAF in September 1940. The tactics employed by the Defiant night-fighter were as difficult as they were unique, as the turret guns (the only armament possessed by the aircraft) were seldom fired forward because their flash blinded the pilot. Instead the aircraft, using its AI radar, would engage in a long stern chase (for the Defiant was slow by comparison with other fighters), gradually draw alongside or beneath the enemy bomber before opening fire with its rifle-calibre guns. Quick direct hits were needed in vital parts of the target before the enemy gunners returned the fire or the German pilot took violent evasive action.

Specifications