I'm getting back into my Russian SKS a little.  It is a Tula 1950 that has been arsenal refurbished, and has the traditional square with line through it on both the receiver cover and stock.  It has the angled gas block and rounded stock, but it is the birch?, not laminated.

My question is what do all the little markings mean in between the upper handguard and the receiver?  There are numerous little marks.  Anybody know where I can find out.  I checked Simonov.net, but it wasn't that detailed.  I would like to learn more about when it was refurbished, and where it went from there.  Could they be regimental markings?  Many are over top of others.  
Thanks, guns762

Can you describe the markings?  They are probably arsenal inspection stamps.  Are they located under the rear sight?

Yes, they are under the rear sight.
I see circles with different things in the middle of them, some letters, and other symbols I don't know how to describe.  Some circles are smaller than others.  One looks like a "K" or maybe an "R", inside the circle.  I also see a "U" or possibly a "J".  I also see a diamond with a "U" or "J" in it.  It is hard to determine, sense the markings are partial, because of the tubular shape they are stamped onto.    There is also a seven on its side stamped over top of some of the circles, others, just by themselves. There are a dozen stampings total on the left side.  There are also sideways "V"s stamped like corporals bars, one above another. There are also more on the right.  I don't have access to a digital camera, or I'd post a picture.

I don't suppose there is a list of Soviet serial numbers, and where the rifles were sent, available to us, is there?