Colt M4 roll-marked lower receiver, with CR series serial numbers Colt M4 factory CAGE Code stamped upper receiver Knights Armament KAC M4 quad RAS rail with three (3) KAC 11-rib covers, custom coated Tan Matech 600m back-up rear site from Picatinny Engineering Colt factory installed front ...
However, to make some sense of their serial system, the prefix in the serial number does indicate a broader class of that weapon. So for example one of the largest classes of their rifles is the Sporter line of ARs, but the LE model is a subclass within the overall Sporter line and in...