1948 Russian SKS

[Power Surge]

The extractor is the only part having a lip on all sks....  but not having the left/bottom rims, I imagine the case going all over the place uncontrolled during extraction prior to being ejected.

Not so much that, but there's no way to set head space. The SKS bolt locks into the receiver by the front butting up against the chamber face, and then the rear dropping down against the the cross bar in the receiver. Without those front lips, that bolt would try to shove that round way too far down the chamber. Unless that particular gun was designed to head space via the case lip in the chamber, but looking at the dimensions of the chamber face in the pics, it doesn't look much different than the receiver I have here.

[Loose}{Cannon]

Im sorry man...  but thise lips have absolutely nothing to do with headspace.  The bottom rear of the bolt sets the headspace to the proper gap based on the round seated at its shoulder.   

Gut an action, insert bolt...  you will have a slight gap front/back with nothing in the chamber. 

[Power Surge]

Im sorry man...  but thise lips have absolutely nothing to do with headspace.  The bottom rear of the bolt sets the headspace to the proper gap based on the round seated at its shoulder.   

Gut an action, insert bolt...  you will have a slight gap front/back with nothing in the chamber.

With a round in the chamber, the front bolt lips do sit right against the chamber face. That also does match where the round sits in the chamber by itself too.

It's very possible that 48 gun was made like that, and the design was revised for 49. The extra lips on the front of the bolt face would serve to better hold the round where it needs to be for the ejector to get it. Without those lips, the extractor would not really hold the case very well against the breech face. The lips would also aid in head space...not so much for setting it, but for not driving the round into the chamber excessively which would wear the chamber out faster. When a regular SKS bolt is in the forward position, it IS locked both from forward and backward movement, by the cross bar in the back and the bolt lip in the front. Without those front lips, that would allow the bolt to "bounce" back and forth upon firing, which would also drive the case into the chamber.

So....it could have been the original design, and then revised for 49.

[Loose}{Cannon]

Upon chambering, the extractor doesn't 'clasp' around the casing until the shoulder is seated and the bolt fully closed, so the only thing holding the round from going cocky is the magazine feed lips.

With my x39 headspace gauges, all my sks have a very small gap between the bolt face lips and the chamber face when seated on empty chamber.  The rims have nothing to do with prevention of over insertion ect.  The critical dimensions of a rimless gauge are the shoulder/angle to the rear oal.  A round is seated when the shoulder seats against the camber wall......  thats what makes it a rimless cartridge.   

[Loose}{Cannon]

Just sayin....  the rims have nothing to do with headspace.   The only time/place where the lip/rim would do anything is after the casing mouth has cleared the chamber opening during extraction, and prior to it being ejected at rearward most travel of the action.   There is an ejector tab milled directly into the inner receiver on the left rail that kicks it off the bolt.   Without said lips/rim, the extracted casing would not be guided consistency into the ejector tab.

[Power Surge]

Just sayin....  the rims have nothing to do with headspace.   The only time/place where the lip/rim would do anything is after the casing mouth has cleared the chamber opening during extraction, and prior to it being ejected at rearward most travel of the action.   There is an ejector tab milled directly into the inner receiver on the left rail.

That's what I was saying above....  the lips would help keep the case centered in the bolt face so the ejector would have the proper strike. With no lips, the case can move on the bolt face upon extraction, chancing a poor ejection.

[Loose}{Cannon]

Yup...     

I guess it 'could' work without said rims, but I dont think very well.  Especially when shooting sideways like a gangster.       

[pcke2000]

Same markings I saw on the 1948 receiver cover I was too uninformed to buy when I saw it 4 years ago here in Canada.  It was a heavy refurb with blade bayo. But the markings were the same. No slit.

This is only the second one I've seen. Did see a stock with 1948 marks though in another collection.

1948 guns do exist.

now I remembered the pictures someone posted on a Canadian forum, but that rifle has a wrong receiver cover take-down latch.

[Loose}{Cannon]

Not sure anyone has seen enough 48s to determine what is/isn't correct.

[fenceline]

Not sure anyone has seen enough 48s to determine what is/isn't correct.

Let alone one complete one.

[jstin2]

Although there is not much information about the 1948 SKS. What is known about it? We know that in the the pictures the bayonet collar is smooth and that is about it. When I posted pictures about the safety lever knurls on my early 50 and my 54, I received a email about a 1949 without knurls. Further information with pictures followed. Although his 49 has knurls on his bayonet collar there are minor transitions from later 1949. I will be making a new post once I have received additional pictures.

[running-man]

Impossible to say because there are so few examples seen. I know of only the two in this thread.  With a sample size of n=2, it is impossible to draw conclusions on minor piece-part changes that may or may not be original to either of the guns in question.  This is why I'm still fairly skeptical on your '50 spike bayo, there is only the single example and all other "EM" prefixed guns have been shown to be '49s or at least have '49 receiver covers.  The smooth takedown lever on your buddy's gun is certainly neat but is it indicative of early '49s, mid 49's, late 49s, or was it a part that slipped through QC somehow?  Maybe bubba exporter Kyber Pass'd one up and installed it to be able to sell the gun?  Impossible to say without seeing other examples on other guns, establishing the pattern and then finally making the determination.  This is what we did with the external rivet on the early '49 magazines.  Justin Hell made the initial observation, we followed up with a deep dive through the data, had quite a bit of discussion, determined that certain 49's had the feature and others didn't, then associated S/N blocks to the guns that did and could finally piece together the story reasonably well that it was an early feature that was quickly transitioned in mid-49.  Absent a primary source who acquires this info from firsthand knowledge (documents, blueprints, museum pieces, interviews with technicians who built them, etc.) that's the best we're ever going to be able to do. 

We can look at the two 48's and see that the two gas tube takedown levers are quite different from the SKS45s that went into production as are the two bayo collars, the receiver cover text, the two receiver cutouts for ejected shells, etc.  Beyond simple 10,000 ft view stuff like that, it's really quite impossible to say much more at the component level in detail with any degree of certainty.  As with the "ex-DDR" internet gospel floating around out there that refuses to go away, I think it would be a great disservice to the SKS community to assume we or anyone in the SKS community could concretely identify all or even most of the changes on these '48s with random photos of just two different guns. 

[jstin2]

I am not stating that his sks is a 48, but has items that may have been carried over from 48. His sks is a 1949.

[running-man]

It could very well be those parts are carried over.  Please accept my apologies if I'm coming off as dismissive or cantankerous, but until I can see the dots connected between the weird parts on that gun and original parts on a '48, I'm going to remain quite skeptical as there are other hypotheses that could otherwise explain it (not the least of which is that the gun in question is a Westrifle import...) 

The ex-DDR fiasco has left a bad taste in my mouth with respect to running with a hypothesis that has tenuous (at best) evidence supporting it. 

[jstin2]

No apologies needed. A person has to be wary if something new pops up. I have also seen several sks that I shake my head at. I have asked for a picture of the gas tube lever as the pictures that I have, does not show this. As I mentioned before, once I receive additional pictures, I will posting it.

[pcke2000]

Similar (or same?) features on rear sight assembly and gas tube take down level on 1947 SKS

[running-man]

There is definitely something to the gas tube takedown lever on these early pre '49 guns.  It is functionally different than what we see on the '49-'58 SKS45s.