parsifal
Colonel
mike williams I think did some work on th relative effectiveness in terms of firepower of various guns. its rather simplistic, but from memory, he rated a typicall 20 cannon at around 2.4, a 50 cal at around 1 and a 0.303 at 0.2 per gun. 30mm cannons were rated at about 6 per gun per unit of time.
Its not that simple of course. a 30mm cannon is an excellent bomber destroyer, but fairly slow projectile and fairly slow rof. As a fighter to fighter weapon it is not as effctive as the 20mm/0.5" combination.
The real battlefield is the debate between the 50 cals favoure by the Americans and the 20mm favoured by everyone else. 50 cal in my opinion is better at range, but far less firepower. given that most air combats of WWII were at 200m or less the 20mm was the better option for most pilots.
Its not that simple of course. a 30mm cannon is an excellent bomber destroyer, but fairly slow projectile and fairly slow rof. As a fighter to fighter weapon it is not as effctive as the 20mm/0.5" combination.
The real battlefield is the debate between the 50 cals favoure by the Americans and the 20mm favoured by everyone else. 50 cal in my opinion is better at range, but far less firepower. given that most air combats of WWII were at 200m or less the 20mm was the better option for most pilots.