Q: What is my Russian SKS's true S/N?

[running-man]

A: Believe it or not, this question isn't as straightforward as it seems.  Yes, the Russians stamped a serial number on the receiver of every single SKS45 they produced.  These S/Ns typically start with a dual Cyrillic prefix, though single Cyrillic prefix S/N's from Izhevsk certainly exist.  The main portion of the number consists of 1, 2, 3, or 4 numerals.  Russian SKS45s from 1956, 1957, and 1958 as well as some 1954 Izhevsk produced carbines will have a suffix after the serial number on the receiver, and in the case of '54 Izhevsks on all other S/N'd components as well. 

Unfortunately, here is where the US government gets involved.  (You guys up in Canada don't have to worry about any of the following! )

27 CFR §478.92 dictates how licensed manufacturers and licensed importers must identify firearms. 
Per the CFR the following pertains to imported firearms (I've highlighted certain important wording that directly relates to Russian SKS45s) :

§478.92 How must licensed manufacturers and licensed importers identify firearms, armor piercing ammunition, and large capacity ammunition feeding devices?
(a)(1) Firearms. You, as a licensed manufacturer or licensed importer of firearms, must legibly identify each firearm manufactured or imported as follows:
(i) By engraving, casting, stamping (impressing), or otherwise conspicuously placing or causing to be engraved, cast, stamped (impressed) or placed on the frame or receiver thereof an individual serial number. The serial number must be placed in a manner not susceptible of being readily obliterated, altered, or removed, and must not duplicate any serial number placed by you on any other firearm. For firearms manufactured or imported on and after January 30, 2002, the engraving, casting, or stamping (impressing) of the serial number must be to a minimum depth of .003 inch and in a print size no smaller than 1/16 inch; and
(ii) By engraving, casting, stamping (impressing), or otherwise conspicuously placing or causing to be engraved, cast, stamped (impressed) or placed on the frame, receiver, or barrel thereof certain additional information. This information must be placed in a manner not susceptible of being readily obliterated, altered, or removed. For firearms manufactured or imported on and after January 30, 2002, the engraving, casting, or stamping (impressing) of this information must be to a minimum depth of .003 inch. The additional information includes:
(A) The model, if such designation has been made;
(B) The caliber or gauge;
(C) Your name (or recognized abbreviation) and also, when applicable, the name of the foreign manufacturer;
(D) In the case of a domestically made firearm, the city and State (or recognized abbreviation thereof) where you as the manufacturer maintain your place of business; and
(E) In the case of an imported firearm, the name of the country in which it was manufactured and the city and State (or recognized abbreviation thereof) where you as the importer maintain your place of business. For additional requirements relating to imported firearms, see Customs regulations at 19 CFR part 134.

The CFR seems really straightforward and you wouldn't think that serial numbers would be the cause of major problems.  Unfortunately, confusion reigned in the '92-'96 timeframe when Russian SKSs were imported and many different methods were tried to satisfy these marking requirements by the 4 big importers of Russian SKS45s during this timeframe.   
NHM decided to issue a totally new number to the Russian carbines, but they constantly changed the way they marked these guns as shown below.  All their Russian SKSs had a 99 prefix on them, with another 5 digit number afterwards.

• They at first decided to stamp a new number right beside the old, original Russian S/N:
  
• Then they decided to try something different and force a S/N to fit where a S/N really didn't fit!
  
  
• Then they decided to billboard print (dot matrix) the number to the rear of the left side of the receiver:
  
• Finally, they decided that the right side of the receiver was a better location for their marks (note the misspelled 'SACCO' instead of 'SAC CA':
  
  

KBI took a similar approach and restamped an entirely new serial number at the rear of the receiver on the left side.  These new serials typically start with an "R" prefix.  These import stamps were tastefully done, though the stamp on the receiver is large and can distract from the gun itself.  KBI imports were typically very good quality guns in above average shape.

• The RL prefix:
  
• The RH prefix:
  

CDI made their numbers truly unique.  They moved them to the right side of the receiver and incorporated a huge engraved font "CCCP" as the prefix to all the numbers. 

• These guns are generally poo-poo'd by collectors who see the S/N as gaudy:
  

Finally we got to CAI.  CAI decided to do something totally different. 

• They placed the country of origin, caliber, and their company name / hometown in a stamp on the barrel, which is perfectly legal.  There are at least two (and I believe three if we take into consideration the Israeli Capture early 'CAI ST A. VT' import stamp):
  
• 

Instead of restamping with a totally new number as the other three importers did, they simply utilized the original Russian stamped serial number.  They attempted to translate all the Cyrillic letters into their Roman equivalents.

• Sometimes the translation was above the original S/N:
  
• Other times it was below:
  
• They even translated the suffix of the Д, И, and K letter guns:
  
• Sometimes they stamped the numbers on the left side and the translated letters form a very confusing run-on sentence with the original number:
  
• Unfortunately, thier inconsistencies and the difficulty of translating Cyrillic got them into trouble, as is seen with this misstamp and correction:
  
• At certain points, it almost seems like they simply gave up and didn't care what they marked or more importantly, where they marked it:
  

Based on these varied interpretations, and likely because CAI made such a mess of the entire process, in 2002 ATF issued ruling 2002-6 which dictated that non-Roman characters are specifically not allowed in serial numbers.  This ruling also dictated that a restamp of the compete serial number is required because of the confusion that a partial restamp (like the CAI examples above) caused when trying to trace a firearm. 

Fast forward to 2012 and the new imports of Chinese Type 56 SKSs from Albania began to pour in.  Mixed in with the Chinese guns were the Russian 'sneaks'.  These guns were marked as Chinese by the importers, but based on various physical characteristics, stocks, receiver covers, and most importantly the S/N they are known to be Russian origin SKS45s. 

• The importers of these Russian sneaks made absolutely no attempt to decipher any Cyrillic portions of the serial numbers:
  

Likely based on this, In 2013, ATF revisited their 2002 determination and issued ATF Ruling 2013-3 which had guidelines for allowing the reuse of original manufacturer S/N, country of origin, caliber, and other marking on imported firearms.  Cyrillic and Greek lettering reuse is strictly prohibited, however. 

So there you have it. 

• NHM, CDI, and KBI imports all have newly designated serial numbers.  The Russian S/N on the receiver or on any of the parts is not your real S/N.
• The CAI guns utilize the numbers of the Russian S/N, however the Cyrillic letters are translated (sometimes incorrectly) into their Roman equivalents.
• The newly imported Russian 'sneaks' all bear China as the country of origin and no attempt was made to translate or renumber these guns.  The Cyrillic S/N is all you have to go on with these guns.

Photos from various auction sites and internet postings are used under 17 U.S. Code § 107, fair use, not for profit educational purposes.  If any of the photos in this post are yours and you explicitly do not want them shown, please contact me.

[running-man]

If anyone has any examples of importer markings on Russian SKSs that are not in my set, please let me know and I'll incorporate them into this post.   

[fenceline]

Good grief, I'll take my piece of metal rod welded to the follower hidden inside the mag over that any day.  Sheesh what a mess.   

[jusridin]

Thanks again RN!

[running-man]

Added the second NHM mark I just found.   Those importers sure did some funky stuff to mark a gun!