Quadruple machine-gun mountings offered a tempting concentration of fire against aircraft approaching at short range. That promise helped sustain Royal Navy interest in the weapon arrangement. Practical experience favoured larger weapons, including 20 mm and 40 mm cannon, because they supplied more stopping power. The comparison explains why a large volume of machine-gun fire did not settle the question of an effective close-range anti-aircraft battery.
Notable Point · 8:49-9:16
Why anti-aircraft stopping power favoured cannon
Quadruple machine guns promised dense fire against approaching aircraft, but practical experience favoured the stopping power of 20 mm and 40 mm cannon.