Left side of receiver has the "S.G.W" letters in a circle inside a hexagon. Under that:
"Cal. .223 5.56
(might be "A2-016XXC," or "A2-1116XX0," it's kinda hard to make these out in a pic.)
Lower has A2 features, i.e. beefed up front pivot pin area, thicker rear ring area where stock tube screws in.
Is this a "preban?" Was it a preban that was sent in to Olympic for "repair," and it came back "refurbished" as it were?
Is such a receiver truly a "preban," worthy of preban price?
Is it ambiguous?
Is it a problem waiting to happen?
Well... I checked out Oly's webpage and got this: "Our current production cast receivers have a serial number prefix of "SGW" which stands for our old trade name of "Schuetzen Gun Works". " I also foudn this: "U1001 U1597 08/18/1987 11/28/1989" So....is it possible the A2 and C were added when they remanufactured it? I would contact Olympic Arms. I'm sure they would have a better idea. THey may not have the original info, but if it was remanufactured im sure they have a record of that.