In other words, you could legally buy a lower frame for a MK III without completing a BATF form but you could not buy a SR1911 lower frame. The serial numbered part becomes the 'BATF controlled part', just as if it were the complete gun. Some guns, such as a Ruger SR1911, are S/N stamped on the lower frame whereas MK Series pistols are stamped on the barrel assembly. Now with the prefix, it would isolate the search to one specific gun, even if the person doing the initial input didn't include the model.Įdited to add: The Gun Control Act of 1968 also required all similar model guns from the same manufacturer to be serial numbered in the same uniform location with a uniform font size. Any Ruger with the same serial number would come up as stolen when indeed it may have been a totally different gun. You can imagine the confusion when a law enforcement agency did a NCCs check for a stolen gun.

Many models are lumped together with the same prefixes, such as Security-Six, Speed-Six, and Service-Six, which were all in the same family. After they ran out of two digit prefixes, they went to three digit prefixes but still maintain unique prefixes for each model. BATF didn't like that so when the new law went into effect in late '68, Ruger started using a different two digit prefix on each model. 123-99999 to 124-00001, or it could be a totally different series.īack before the Gun Control Act of 1968, Ruger used the same serial numbers on all different models so it was possible to have a Standard Pistol, Bearcat, Hawkeye, 44 Carbine, Mod 77, 10/22, Single-Six, Blackhawk, or a Super Blackhawk, all with exactly the same serial number.

Once a serial number gets to 99999, the next series is used. Each series is unique to a specific model. Each two or three digit prefix is called a 'series'.

Ruger old single six serial numbers