Were the 303 rounds useless? 180 8k

While Germany started the war with cannons mounted to their aircraft and the Americans showed up with 50 calibre machine guns in the wings of their aircraft, the British started the War with 303 ammunition on it's aircraft. A round designed almost 50 years earlier for infantry rifle use. Was this a decision based on stubbornness or were practical considerations more at play?
#aviation #ww2 #history #militaryhistory

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