I respectfully withdraw about 15% of the post I made above, as I was missing the "30" in "Mini 30" and read "14" in my head.
I'd still take the M1A, a Springfield built one, which is the paradigm that I speak of when I say M1A. AFAIK that's a trademark of Sprinfield, although it's been co-opted by others as a generic term. Polytech? Uhh... No.