Okay, it's not a USGI receiver.
I have upgraded my NFA Registered full auto M1A receiver with the following components. The intent was to build this automatic rifle shooting 143 to 150 grain ammunition with more updated and durable parts.
Smith Enterprise, Inc. dove tail Vortex (R) flash hider
Smith Enterprise, Inc. forged M80HT treated gas cylinder with stainless steel shims
Smith Enterprise, Inc. cyrogenically treated and chromium plated gas piston
CS Speedlock chromium silicon alloy steel operating rod spring
Smith Enterprise, Inc. S-7 tool steel connector lock
Smith Enterprise, Inc. extended bolt lock
Sadlak Industries, LLC National Match operating rod spring guide
LAW483 wood laminate M14E2 stock with USGI hardware and commercial engine enamel and ceramic resin finish
MD Labs XF7 weapons lubricant keeps her lubed
Major parts - USGI M2 bipod, TRW barrel, Winchester bolt, Winchester operating rod, USGI firing mechanism including a TRW trigger housing, HRA safety and HRA hammer.
I had to sand a little off the top edges to fit the stock to my receiver. Other than that, it looks and feels great.
I'll get it to the range for sighting in ASAP.