Dec 15, 2016 - Hello, I recently acquired a Polytech Legend and I just had a couple. The serial numbers matched (P47-12001) except for the serial number on.
My latest M-14/S serial number 0057X has the following stamped on the left side of the receiver below the stock line. 88 01 21 so I take this to mean the rifle was made January 21, 1988 or at least that was when the receiver was forged at the foundry. 7th It's January 1988 for that receiver.
After about the first 2000 Chinese M14 rifles imported into the United States, the 'lotto number' format changed. You can still decipher the meaning but you have to understand how the numbering was arranged. I should do a You Tube video to explain the secret Chinese M14 lotto code. Glenn Beck, watch out!