Besa (gun)

Besa machine gun
Besa machine gun
Type	Tank-mounted medium machine gun
Place of origin	United Kingdom
Service history
Used by	United Kingdom, Ireland
Wars	Second World War
Production history
Designer	Václav Holek
Designed	1936
Manufacturer	The Birmingham Small Arms Company Limited
No. built	7.92mm: 39,332 in all variants. 15mm: 3,218 total production.
Variants	Mark I (1939–1940) Mark II (1940–1943) Mark II*(1943) Mark III (1943–1951) Mark III* (1943–1952) Mark III/2 (1952–1966) Mark III/3 (1954–1966) 15mm Besa Mark I (1939?–1949)
Specifications
Weight	47 lb (21 kg) empty
Length	43.5 in (1,100 mm)
Barrel length	29 in (740 mm), 4-groove rifling with Right Hand twist.
Cartridge	7.92×57mm Mauser
Calibre	7.9mm
Action	gas automatic
Rate of fire	450–550 round/min (Low) 750–850 rounds/min (High)
Muzzle velocity	2,700 ft/s (823 m/s)
Feed system	7.92mm: 225 metal link belt. 15mm: 25-round link belt.

The Besa machine gun was a British version of the Czechoslovak ZB-53 air-cooled, belt-fed machine gun, which in the Czechoslovak army was marked as the TK vz. 37. It was used extensively by the armed forces of United Kingdom during the Second World War, as a mounted machine gun for tanks and other armoured vehicles, to replace the heavier, water-cooled Vickers machine gun. Although it required a rather large opening in the tank's armour, it was dependable and reliable. The name came from the Birmingham Small Arms Company (BSA), who signed an agreement with Československá zbrojovka to manufacture the gun in the UK. The War Office ordered the weapon in 1938, and production began in 1939, after modifications.

Although Britain's armed forces used the .303 in rimmed round for rifles and machine guns, the ZB-53 had been designed for the German 7.92×57mm Mauser round – referred to by the British as the 7.92mm. Although it had been intended for the British to move from rimmed to rimless ammunition generally, with war imminent wholesale change was not possible. It was considered by BSA and the Ministry of Supply that the industrial, technical, and logistical difficulty of converting the design to the .303 round would be more onerous than retaining the original calibre, especially given that the chain of supply for the Royal Armoured Corps was already separate from the other fighting arms of the British Army. As a consequence, the round was not changed for British production. Since the Besa used the same ammunition as Germany used in its rifles and machine guns, the British could use stocks of captured enemy ammunition.

While American-produced armoured cars or tanks would have been fitted with .30 cal Browning machine guns, many British tanks and armoured cars would be equipped with the Besa machine gun. It fed from non-disintegrating disposable 225-round steel metal-link belts.