Deck crew refuel and rearm F4F-3 Wildcats 1 February 1942
At the start of World War II, the U.S. Navy was equipped with two primary machine guns: the .30 caliber M1919MA4 (AN-M2) and the .50 caliber M1921M2. These weapons, manufactured for both land and air combat, were installed on almost all U.S. Navy aircraft. The .50 caliber M2 Browning had already established a solid reputation, being highly effective and widely used across various theaters. However, while the machine guns were dependable, the early Navy fighter aircraft were not entirely up to the task. The F2A Buffalo fighters, once a solid design, were outdated by 1941. Despite the .50 caliber Browning machine guns proving successful, the Buffalo itself was no longer competitive against newer aircraft models. This left the U.S. Navy with a pressing need for more advanced fighters, although mass production of newer designs would take time.
Grumman F4F Wildcat: A Promising but Flawed Design
The Grumman F4F Wildcat was more promising, designed with four .50 caliber guns and reliable heavy armor. However, the early Wildcats had several design flaws, one of which was the tendency for its ammunition belts to kink during high-G combat maneuvers, causing the machine guns to jam. This issue stemmed from pre-war testing, which didn’t push the aircraft to its full combat limits or account for extreme conditions encountered during battle. The problem of jamming, particularly with the M1921M2 machine guns mounted in the wings, persisted through the first year of the war.
Rear Defense on Dive Bombers and Torpedo Bombers
While the Navy’s fighter planes like the F4F Wildcat had offensive firepower, dive bombers and torpedo bombers, such as the SBD Dauntless and TBF Avenger, initially faced challenges in defending themselves. These aircraft were often slow and vulnerable, relying on twin .30 caliber Browning M1919 machine guns for defense, which proved ineffective against fast and agile Japanese fighters. Positioned in the rear fuselage, these guns were only useful for defending against direct stern attacks and did little to deter experienced enemy pilots. By the end of the war, the defensive armament of dive bombers and torpedo bombers had improved significantly. These aircraft were upgraded with twin .50 caliber M2 Browning machine guns, giving the rear gunners of SBD Dauntless dive bombers and TBF Avenger torpedo bombers a much better chance at fending off enemy attackers. The increased firepower allowed these bombers to defend themselves more effectively during missions, making a marked difference in their survivability and combat performance.