In "Americas Munitions 1917-1918" Report of Benedict Crowell, The Assistant Secretary of War, Director of Munitions Government Printing Office 1919
he writes on the subject of small arms production specifically the M1917 Rifle. ( page 182)
"In the second place, standardization is essential to great speed in production. If one plant producing rifles encounters a shortage in any of the parts of the gun, it can send to another plant and secure a supply of these parts, a favorable condition in manufacture that is impossible if the weapon has not been standardized."
Now it may have never occurred in actual practice but there it is in writing, in the words of the guy responsible, what the production people were actually considering at the time.
Regards,
Jim