Over a span of just 38 months (the first carbines were delivered in June 1942, the last in August 1945) nine primary contractors established manufacturing facilities, tooled up and turned out some six million carbines of all types - M1, M1A1, M2 and T3/M3. The production program was such a success that, excepting Inland and Winchester, the remaining contracts were cancelled in mid-1944. Those two companies completed their carbine production runs in August, 1945. Only 413,017 of the US .30 Carbine were made by National Postal Meter, out of a World War II production totalling 6.1 Million - about 7 per cent.
This makes this carbine one of the more collectible makes. National Postal Meter did not make barrels & used barrels from Marlin, Underwood & others.