So i purchased my first AR, its a colt sporter lightweight, The serial number reads
SL0019XX I know its definitely preban, but i cannot find a specific year on when it was built, I even went as far as calling COLT they said it was preban but have no furthur info on that serial. It is one without the bolt assist. has birdcage flash hider and boyonet lug. Barrell is 20 inch with (c mp chrome line barrel) How can i determine what year it was built?? I just want to confirm the originality of the rifle, From my research it apears to have parts from the vietnam era AR but some specs of the early 80's AR's. Im confused.