Browning .303 Mark II - Aviation History
...It had a rate of fire of 1,150 rounds per minute a muzzle velocity of 2,660 ft/sec. The major advantages were that it was lighter, accurate, and available in large numbers. Near the end of the war, the RAF began adopting .50 caliber machine guns in their bombers....
http://aviation-history.com/guns/303.htm
M1919 Browning machine gun - Wikipedia
...The Browning was adopted by the Royal Air Force as a replacement for the .303 Vickers machine gun and manufactured by Vickers Armstrong and BSA to fire the British .303 inch (7.7 mm) round and named "Browning .303 Mk II" in British Service....
https://en.wikipedia.org/wiki/M1919_Browning_machine_gun
Why did the RAF persist with the .303 throughout the war?
...Not just the Air Ministry, the Navy quad .5 had each gun pointed to a slightly different place so that at any likely combat distance (plane is not crashing onto the gun mount) only one gun could hit a plane at time....
https://ww2aircraft.net/forum/threads/why-did-the-raf-persist-with-the-303-throughout-the-war.37878/
Browning .303 Medium Machine Gun (MMG) / Aircraft Machine Gun
...Page details technical specifications, development, and operational history of the Browning .303 Medium Machine Gun (MMG) / Aircraft Machine Gun including pictures....
https://www.militaryfactory.com/smallarms/detail.php?smallarms_id=1017
British .303 Browning Mk II* Aircraft Machine Gun
...This was essentially John Browning?s air cooled M1919 machine gun made smaller and lighter, with an increased rate of fire, and reversible feed direction. British adoption began with the purchase of 60 guns and a license for domestic production....
https://www.forgottenweapons.com/british-303-browning-mk-ii-aircraft-machine-gun/
A retrospective: Bomber Command?s Browning .303-calibre Mark II machine gun
...There were a number of factors behind the decision taken by the powers that be to equip bombers with .303-inch guns; they included weight, reliability, rate and volume of fire, expected range and conditions of encounters and defensive tactics....
https://militaryaviationchronicles.com/wwii/a-retrospective-bomber-commands-browning-303-calibre-mark-ii-machine-gun/
Browning 0.303in Mark II Machine Gun - HistoryOfWar.org
...The longer range of the heavier guns was more useful in daylight operations, and was of little benefit at night, at least until radar assistance was available for gunners....
https://www.historyofwar.org/articles/weapons_browning_mkII_raf.html
Browning .303 Mark II Machine Gun | This Day in Aviation
...The Mk.I?s range was 600 miles (966 kilometers) at 175 miles per hour (282 kilometers per hour). The fighter was armed with eight Browning .303-caliber Mark II machine guns mounted in the wings. At the beginning of World War II, 497 Hurricanes had been delivered to the Royal Air Force, enough to equip 18 squadrons....
https://www.thisdayinaviation.com/tag/browning-303-mark-ii-machine-gun/
.303 Browning Machine Gun Mk II* | Imperial War Museums
...During the Second World War the Browning armed a variety of British aircraft, either mounted in the wings or in power-operated turrets. Most .303 Brownings were produced by the Birmingham Small Arms Company, although some, like this example, were produced by subcontractors....
https://www.iwm.org.uk/collections/item/object/30034662
Why Did The RAF Use .303 Caliber Machine Guns in WW2? The Surprising ...
...During the First World War, British aircraft has been equipped largely with either the Vickers machine gun or the American-designed Lewis machine gun. Now, these were both armed with 0.303 caliber rounds....
https://warbirdfanatics.com/2023/03/02/why-did-the-raf-use-303-caliber-machine-guns-in-ww2-the-surprising-answer/