Barrel Lug: Uncertain pinned
Battle Sight on RSL: Uncertain
Bayonet Type: Deleted spike
Bayonet Lug: Late, neutered
Bolt Carrier: Late Non-Cut
Gas Tube: Early one piece
Gas Block: Cast, bulbous
Receiver Cover Takedown: Normal
Rear Sight Block: Uncertain late
Serial Number Format: X Digits, 1,607,722
S/N on Components: Last 5 digits
S/N on Stock: Last 5 digits,
Stock Swivel: Side
Trigger Group Type: Late Stamped