Buffalo arms produced AN/M2 .30 Browning MG, M1919A4 Browning MG, and mainly the M2 .50 Browning MGs. Their production of the M1919A4 was halted early to focus on M2 .50 Browning production. The M1919A4 shortfall was made up by Saginaw Steering Gear of GM the major M1919A4 producer. Its my understanding that in 1943, the US Ordnance Department decided that US commercial plants should focus on one major weapons system for Buffalo Arms that was the M2 .50 caliber Browning MG. Buffalo Arms still produced other parts and weapons systems for the M3 SMG and M1 Carbine. Early in WWII, Buffalo Arms also produced .303 caliber Aircraft Browning for the Brits. Buffalo arms also produced the M3 and M4 .22LR caliber conversion kits for the M1917A1 and M1919A4 Browning MGs. Buffalo Arms was contracted to manufacture others parts as other part contracts were completed. I hope this was helpful.
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--fjruple