That armament was quite heavy for WW2 American fighters (which largely relied on four to six 0.5 inch machine guns) but German and Britsh fighters usually mounted multiple cannon. The RAF Beaufighter (used as a night fighter and anti-shipping strike fighter) mounted four 20 mm cannons in the nose and six 0.303 inch macine guns in the wings. The Mosquito carried four of each (all in the nose), and German night fighters had similar weapons. Among single engined fighters, there were variants of the Focke-Wulf 190 which carried a pair each of 20mm and 30mm cannons, as well as a pair of machine guns. Most marks of the Spitfire had two 20 mm cannons and four 0.303 inch machine guns, and some carried four 20 mm cannons.
Best, Raptor
Best, Raptor