Vickers .50 machine gun

Vickers .50 machine gun

 Vickers .50 machine gun

  Vickers .50 machine gun

  Vickers .50 machine gun

  Vickers .50 machine gun

  Vickers .50 machine gun

  Vickers .50 machine gun

 Vickers .50 machine gun

The Vickers .50 machine gun, also known as the 'Vickers .50' was basically the same as the .303 inches (7.70 mm) Vickers machine gun but scaled up to use a larger calibre 0.5 inches (12.7 mm) round.
Mark I
Mark I was the development model.
Mark II, IV and V 
Mark II entered service in 1933 and was mounted in some British tanks. Marks IV and V were improved versions and were also used mounted on trucks in the North Africa Campaign. It was superseded for use in armoured fighting vehicles (AFVs) during World War II by the 15 mm (0.59 in) Besa.
Mark III 
Mark III was a naval version used as an anti-aircraft weapon, mostly by the Royal Navy and allied navies in World War II, typically in mountings of 4 guns. It proved insufficiently powerful in the short-range anti-aircraft role against modern all-metal aircraft and was superseded during World War II by the Oerlikon 20 mm cannon. The naval quad mount featured a 200 round magazine per barrel, with a maximum rate of fire of 700 rounds per minute, per gun.
During the Second World War it was also mounted on power-operated turrets in smaller watercraft such as Motor Gun Boats and Motor Torpedo Boats.