If it has a rear lug, it’s by default a Supermatch receiver. Typically SAI can only tell you if it was sold as a Supermatch rifle, or receiver only, and month and year of when it was sold. Sometimes if a custom stock was ordered that will be noted, but that’s about it. They don’t have a lot of data.
Fwiw, I have a 67k Supermatch (lugged) receiver that was sold as a receiver only. That’s all they could tell me. However, based on barrel markings, I could surmise that it was built by Champions Choice into a Supermatch rifle in late 1991 or early 1992 (heavy Barnett barrel was stamped “CC” and date stamped 10-91). If you post pics of barrel with op rod pulled back, that can sometimes provide some info. If it’s unmarked it’s likely the original Douglas SAI barrel. Glen Nelson also used a distinct brown bedding material in that area and that can help identify it was built by his shop. (Pics are needed with action out if stock to show bedding).
The other clue on my 67k Supermatch that it was not built by Glen Nelson for SAI is that the rear lug had been carefully threaded for a torque screw. SAI/Nelson never did that to their factory Supermatches, so it was done by the builder at Champions Choice (in Tennessee).
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