Comments by "Steve Valley" (@stevevalley7835) on "USS Iowa - First of the Fast" video.

@brendonbewersdorf986 the Browning designed M1 was tested by the Navy, in the late 30s, but was bested by the Bofors, which participated in the same trials. In a world without Bofors, or if the Nazis had paid heavily to obtain an exclusive license from Bofors, then I can certainly see the M1 performing fairly well in it's place. But, seeing how the big dogs at BuOrd behaved in the late 30s, seems like the M1 may have been rejected because "not invented here". In one flight of fancy, I conceived of belt fed M1s in a quad mount patterned after that used with the Vickers Pompom, and single, flex mounted M4s, with a quick change magazine, used in place of the Oerlikon.
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@brendonbewersdorf986 the M1 was an Army AA gun that was mounted on a towed trailer, or half track. The M4 was used in the P-39, and PT boats. The M4 was smaller, lighter, with a lower muzzle velocity. M1: length 104", weight 365lbs, muzzle velocity 2600fps. M4: length 89.5" weight 213lbs, muzzle velocity 2000fps. For comparison: Bofors muzzle velocity 2890fps, Vickers pompom low velocity: 1920fps, HV 2400fps.
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@brendonbewersdorf986 The M1 used a rigid 10 round clip that fed from the left. The M4 used a fixed, 30 round, endless belt magazine. The M9 and M10 were updates of the M1 and M4 that used metal link belts and could be built to feed from either the left or the right.
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