26 Nov 19
Serialization of various parts of military rifles and pistols was necessitated in a bygone era of manufacturing, where much hand-fitting was necessary at the end of the production process, and parts were thus not
interchangeable between individual guns.
Accordingly, consumers understandably wanted a way to keep together all parts assembled at the factory into one gun.
In those days, guns were “roughed-out” by machine, then “finished” by hand. Individual parts were carefully adjusted and modified, as appropriate, so that they worked perfectly together.
Thus, “matching serial numbers” were valued, indeed highly prized.
Today, “hand-fitting” is confined to expensive sporting and “collector” guns.
With current production military guns, and other guns designed for serious purposes, matching serial numbers, at least with regard to functionality, are irrelevant.
With modern serious guns, matching serial numbers attain relevance only within the arbitrary discipline of “collector value”
Until 1968, it was not legally required that rifles manufactured in the USA be serialized at all, although by then most were!
Even so, serialization was required only of receivers.
With modern manufacturing methods, and parts that are completely interchangeable between individual product copies, serialization of any part is no longer necessary for the sake of quality control, as noted above, although it is still a legal requirement for receivers.
Most manufacturers continue to serialize other parts as well, mostly due to tradition and bureaucratic momentum.
Many Glocks we see in our Courses are “parts guns.” So long as all parts are “OEM” (Original Equipment Manufacturer), those guns are every bit as functional as new, out-of-the-box pistols.
With ARs, it is pretty much the same!