Interesting '51 receiver cover stamp

[Bunker]

That's right I remember that now.  What I did notice regarding the Russian AK is almost all (with maybe a few exceptions) have the Circle 'Y' stamp on the barrel and Circle 'K' and 'O' on the receiver.  Also, like GM mentioned, seems the markings varied from plant to plant but I do agree the marking (s) represents the same type of test.   

[Bunker]

And the same (o) stamp is found on a Romanian M1969 .22lr trainer barrel

It's these Romanian examples that are hard for me to understand and make sense in my pea brain.  Unless possibly (just a thought) that they adopted these markings and they represent the same type of tests? 

[Greasemonkey]

And the same (o) stamp is found on a Romanian M1969 .22lr trainer barrel

It's these Romanian examples that are hard for me to understand and make sense in my pea brain.  Unless possibly (just a thought) that they adopted these markings and they represent the same type of tests?

They are all Communist nations, they adhered to the same testing, so they maybe used the same marks, or one supplier did it all, pick your poison....my '55 Romanian M44 with both (k) and (o)

[Bunker]

To me it would make the most sense if the different countries adopted and applied the markings since they are test firing markings.

[Loose}{Cannon]

To me it would make the most sense if the different countries adopted and applied the markings since they are test firing markings.

Then you would expect to find them on all other sks nations......  Which you do not.

[Bunker]

This is true but what kind of agreements and licensing did each nation have and possibly not every nation wanted to adapt those markings or standards.  I don't know...just food for thought stuff since I don't have a reasonable explanation from what I currently know.

[Loose}{Cannon]

This is true but what kind of agreements and licensing did each nation have and possibly not every nation wanted to adapt those markings or standards.  I don't know...just food for thought stuff since I don't have a reasonable explanation from what I currently know.

I dont know either, but it sure is worthy of investigation and further research. 

[Greasemonkey]

To me it would make the most sense if the different countries adopted and applied the markings since they are test firing markings.

Then you would expect to find them on all other sks nations......  Which you do not.

These marks seem to follow the Mosin, Yugoslavia produced and used the Mauser, but made an SKS, no matching marks. Same with Albania, they used whatever went bang, but adopted the SKS, again no marks. Romania, yes they used the Mauser, but, it also produced the M44.  Now Bulgaria and Hungary made a Mosin also, but no documented production of an SKS. And, while there has been reported Albanian M91/30s, again, finding one to check the barrel shank for markings, good luck

Only other SKS is EG and NK, Germany used the Mauser, never seen them on any German weapons, North Korea, I'd guess maybe they produced a Mosin, but given their constant stand off'ish political situation, they may have adapted  their own marks.  NVA, well,  I smell strong Chinese involvement, so we will just cast that one out.

I've checked my Romy Tok, Bulgarian Mak, Yugo M57 Toks, and a few others, none of these marks are used on handguns I could find, other than maybe the Nagant, which mine doesn't have these marks.

As of right now, seems these marks follow the Russian, Romanian and Chinese rifles, regardless of caliber, be it x54r, x39 or .22lr