North American A-36 Apache. The dive bomber mustang with dive brakes and nose guns

I just can’t see how you can keep misunderstanding what I very plainly said. The erroneous thinking is that US designers continued to use the .50 as a cowl gun. Several US fighters of the 1930s used either one .30 Browning and one .50 Browning, or two .50 Brownings. This continued into WW2 with the early models of first-line fighters. As I said, synchronization cut the fire rate in half on the .50. Meaning if you installed one cowl .50, you had half the firepower of a wing-mounted .50. If you installed two cowl .50s, you effectively had one .50 for the weight of two. It should have been obvious the first time that was tried that the .50 doesn’t work well as a synchronized gun, yet US designers kept doing it. Worse, they kept doing it well into WW2 where it was no longer just an academic concern. Additionally, you can reasonably question the general idea of the cowl gun in the WW2 context. Cowl guns were a holdover from WW1 where they were the primary armament. In WW2 they almost universally became “secondary armament” for fighters which also carried more effective autocannon armament. This idea also can be criticized for several reasons. \-“Concentrated firepower” is a valid argument when applied to effective guns like the P-38 (4x50s and 1x20mm) or the Me-262(4x30mms) but is a specious argument when applied to cowl-mounted rifle caliber machine guns in the WW2 context. Even the British, who tried 8-gun RCMG (all free-firing in the wings) understood pretty quickly that the day of RCMG armament was over. \-most (not all) cowl guns were RCMG and basically ineffective (or very marginally effective) against WW2 fighters. Thus a good argument can be made that they should have been deleted and the weight used elsewhere or put back into performance. \-Cowl guns were arguably to be used for sighting purposes for the primary autocannon, but frequently they had significantly different trajectories making this idea ineffective. \-Speaking from a design perspective, it was never realistically possible to cowl mount enough of the main armament, in an effective caliber, to realize the benefits of “concentrated firepower” in the way that various twin engine aircraft could with a completely available nose section. For example, the best the Me-109 could do was the engine-mounted 20 or 30mm, plus two 15mm HMGs. You just couldn’t cram four HMGs, the engine, and the Autocannon into the nose of a reasonably sized fighter.