Thank you for all the input. Confirms my suspicions! I didn't pay a premium price for the rifle (should have been my first clue) and this was a Pawn Shop Chain (there are 9 by this name in town and they have a pretty good business in firearms), not a "real" gun store.
Occasionally, in podunk west Texas, you'll find a steal. . .found a Fox BSE double barrel in a pawn shop for $275 once, heh, heh. But I digress. I took the thing back and they did, indeed, fall all overthemselves getting my money back to me. I don't remember the penelty for this particular felony, so I make up something and they did a collective gulp. I considered leveraging some extra green for the position they put me in, but gave them the benefit of the dumb. It was a devil gun anyway. . .the SN was 26 666 :-)
So will just buy a new AR from Rock River. . .I learned that I might be eligible for a club discount for that match rifle they have. Just discovered a group in town that actually shoots at (gasp) targets and competes in (faint) 4 position CMP and NRA competition. Heck this was what I did for many years in smallbore. . .
And, if I need an adrenaline rush I can still put a 40 round magazine in the thing and unleash a reign of terror in the back pasture.
Thanks, brothers, for guiding me toward what was necessary. Dave