Why was the P-38 Lightning such a good gun platform?

Most American fighters of the era carried their guns in the wings, with trajectories harmonized to cross at one or more convergence zones; beyond that distance, the stream of bullets lost effectiveness. The P-38 broke with that practice and grouped all its armament in the nose of its central nacelle. The P-38E's combat configuration, settled after trials between March and June 1941, combined four Browning M2 machine guns and a 20 mm Hispano cannon with 150 rounds. Even at the design stage, the nose was seen as an excellent gun platform in which to concentrate heavy firepower.

The nose guns did not suffer as much from range limits caused by convergence, so a skilled pilot could fire effectively from much further away. The cannon, with heavier ammunition and a different trajectory, was angled slightly more upward so that its rounds and the .50-caliber bullets would meet between 350 and 400 yards. The result: a Lightning could reliably hit targets at any distance up to 1,000 yards (900 m), while other fighters' wing-mounted guns were optimized for one specific distance. The combined rate of fire exceeded 4,000 rounds per minute, and roughly one in six rounds was a 20 mm shell.

That accuracy accompanies the aircraft's record in the Pacific, where the P-38 shot down more than 1,800 Japanese aircraft and more than a hundred of its pilots became aces. Dick Bong, the top American ace of World War II, scored his 40 kills in P-38s by closing straight in on his targets to make sure of the hit.