I was reading about Werner Voss's last dogfight and found a passage that said that one of the British aces disengaged to change the magazine in his Lewis gun. Did they carry extra magazines? Were these strip or drum magazines (different guns are designed with different magazines, but I assume that either drums or strips were preferred for air combat), and what was their capacity? Where did they store them?
I know that WWII planes often only carried enough ammo for something like 20 seconds of sustained fire, which considering the range of WWII planes isn't very much ammo at all. Given that WWI planes only had a range of around 100-150 miles, carrying extra ammo almost seems like an unnecessary weight for the plane.
The Lewis Gun had a 97 round pan magazine attached to the upper wing on a 'Foster Mounting' that allowed the pilot to pull the gun backwards and change the magazine. Bear in mind the rate of fire on the Lewis gun was around 500rpm and that gives the pilot around 12 seconds of firing time.
The SE.5a carried two spare magazines in the cockpit, and changing them in flight must have been an interesting operation!
I know that WWII planes often only carried enough ammo for something like 20 seconds of sustained fire, which considering the range of WWII planes isn't very much ammo at all.
Its less about range and more about the weight of fire. The early models of Spitfire and Hurricane carried eight machine guns, with the SE.5a only carrying two - one of which was basically an infantry squad's light support weapon.
The British typically equipped their fighters with 300 to 350 rounds per gun, meaning they were carrying around 70kg of ammunition and firing 160 rounds per second with a mix of ball, AP, incendiary and tracer ammunition.
EDIT: The rate of fire of the Lewis guns modified for use on aircraft was actually increased to 700-750 meaning the 97 round magazine would last about 8 seconds, not 12.
