The SAI aren't all USA parts...(I think this was probably hashed out over the years on this forum)
As of February, 2004, Springfield Armory, Inc. M1A receivers are made by Alphacasting, Inc. in St-Laurent, Quebec, Canada for Springfield Armory, Inc. Alphacasting, Inc. makes the M1A receiver by the lost wax investment casting method. In business since 1991, it is a precision casting firm that makes parts from aluminum, bronze, and many grades of carbon and stainless steels.
M1A bolts and operating rods are most likely made in the USA.
Wayne Machine, Inc. (Taiwan) makes the small parts including the sights, bolt lock, gas cylinder, etc.
Interesting that John C. Garand was from Quebec, and fitting for this M14/M1A evolution of his original M1 rifle to be cast in QC.
So.. should we say that we Canucks can be proud of metallurgy and steel quality re: receiver, the heart of the rifle.