And a little more to that - all these manufacturing companies were contracted to complete xxxx numbers of M1 Carbines per allotted timeframe. There was a HUGE push to rapidly field the M1 Carbine. Rockola might have had a thousand receivers and no barrels or bolts. IBM is sitting on SOME bolts, but no receivers or barrels. Winchester would have barrels, and need bolts. Singer might have receivers (only thing they produced)...
They would trade. Seriously. Deals left and right with the other companies, to make the quota, and get those carbines produced.
Here's a list of the companies that made M1 Carbines:
Over 6 million carbines in 38 months...
M1 Carbine Production
Inland Manufacturing Division, G.M.C......
2,632,097
43.0%
Winchester Repeating Arms Co................
828,059
13.5%
Underwood-Elliot-Fisher Co..................
545,616
8.9%
*=right>
Saginaw Steering Gear Div., G.M.C...........
517,212
8.5%
**=right>
National Postal Meter Co....................
413,017
6.8%
***=right>
Quality Hardware & Machine Co...............
359,666
5.9%
International Business Machines Corp (IBM)..
346,500
5.7%
Standard Products Co........................
247,160
4.0%
Rock-Ola Co.................................
228,500
3.7%
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Total:
6,221,220