I think that a lot more information has come to light on these early Russians with the data culled from Canadian imports vs. the tiny amounts that survive without bubba intervention here in the states.
It seems likely that a few component configurations existed concurrently or intermittently as parts were modified along the way. The 49/50 differences probably started late 49 and shuffled through 50's upsetting confusion in design changes. I think the differences we see between letter prefixes might prove to be priceless in determining what is likely to be original...it would be a hoot if we could figure out the entire Russian serial mystery with enough data from this mess of changes in a few months time.
Good stuff guys.
When we find 50's components on what otherwise would be considered 49's and that short period of time to have THOSE components to work with at rebuild, stock ferrules and gas blocks seem to be a major PITA...with the FSB in the way of all of it. The most likely components to need replacement would be gas blocks and barrels if horribly maintained. Later refurbs you would expect major scrubbing, and more than likely more modern replacement parts.
We should be able to narrow down a rough timeline based on the unlikelihood you will ever find:
A non chromed late gas block straight eared bayonet lugged FSB Or
a chromed early gas block angle eared bayonet FSB with a 45 degree gas block...
There has to be an order of this that even refurb wouldn't allow for.
If barrels were replaced, and barrel components were reused...shouldn't we find chrome barreled 49s with all/most original components? For that matter, non chromed barrels with late RSBs, late gas blocks, and straight eared FSBs to recycle perfectly good bayonets? Considering the Russians never used the SKS in any wartime situation enough for heavy wear, the refurb excuse for the mishmash of parts seems less likely to me than concurrent use until parts supplies were used up, heck...some of these design changes might have been test runs. (Latches seem quite likely to have been experiments.)
What seems likely to me is a concurrence of several overlaying parts changes that could have made for a sloppy mess for the 49/50s. I would find it amusing that the takedown latches might be key to isolating at least some of the changes, since there were so many latch changes in 50.
At the least, it seems like the bayonets may have run concurrently through the 49/50 border o' dates...and it seems that only pinless mags and same length cleaning rod nubs could be reliably dated to being 49 (and earlier). Everything else seems to be a bit of a shuffle between what was on hand at the time, and dated to a brief period of time (45 degree blocks for instance)....and what would make sense for even needing replacement in the time frame that could make for such confusing guns as we have recently seen in this era.
Many of us have owned a particular SKS for decades...of those, how many components have been actually worn out to the point of needing a totally new component? The amount and frequency of xxxxed out stock serials seem to indicate to me that refurbs often were done without real need for refurbishment. The same goes for scrubbed and reused components. It appears that varying degrees of refurb could happen across small to huge amounts of SKSs at any given point....the degree of care keeping original parts together seems to have a direct relationship to the degree they refurbed them.
The reasoning behind what components are serialed seem to be in direct contrast to why we consider them to be important. They would find parts that were good fit at refurb, assemble a gun and send it off to get matched. The matching likely was simply so groups could break down rifles together and still get the component conundrum solved with relative ease afterward.
I have seen modern video of Russian girls training with AKMs...and was fascinated by the degree of disassembly, and speed that they do it in. One of the first steps oddly enough is karate chopping the rear sight ladders off....WHY? Dunno, but they are serialed...so it matters not. It is the Russian way...seems completely insane to remove them...but they do it, and it friggin pisses me off the ease they do it with...despite how adorable it is seeing high school chicks taking down guns with Bruce Lee speed.
It seems to me that with this attitude, pretty much the only things that couldn't be humped from gun to gun were actually pinned in place are likely the only parts to be original to any barreled receiver. Beyond that...all bets are off on original. Brand new replacement parts could easily be stamped to match receivers, such as gas tubes, magazines...and even misdated covers. The point of serialling anything removable seems to be so that small gatherings of end users could service their weapons and not let the vodka impede on getting their slightly fit to perfection components back together.
Some great information could be culled from the gun murdering and chopping parts guys currently hard at work in Canada. You consistently see barrels offered for sale with no paint where barrel components were removed. This should indicate that barreled receivers were unlikely to be separated of their main components even under heavy refurb. Despite the small numbers manufactured in the early years, there to this day is no shortage of spike bayonets IN Russia. Refurbing to match a standard does not seem likely to me due to me not seeing (yet) one of these stripped barrels with both a top and bottom pin groove for supplanted stock ferrules to 'upgrade' to the blade standard.
Also, something to consider...we have seen actual factual pre 49 SKSs, with the Russian concept of refurbing...it would not shock me in the least since we just DO NOT see non refurb 49s...that the trial gun components between 45-48 ultimately ended up on 'production' guns in 49. I speculate that the spike bayonet was likely abandoned before 'full' production even began. There was no sense in wasting parts that hadn't even been used yet...so we end up with this partial year of 'production' that was 1949...and a whole bunch of tweaks in the upswing of production in late 49 into early 1950. By late 50, major design changes were essentially done...and the changes to come would be mostly minor and seemingly resource saving based. Heck, they even figured out how to make consistent stars on curves.
The inner politics of this era of Russian firearms should also be considered, in a few short years tremendous changes came. We go from the bolt action to the semi automatic to fully automatic in such a brief period the old guys must have been crapping their pants. The term conventional kind of went out the window in short order. Like going from a break barrel pellet gun to a bullpup almost overnight, the SKS seems to be the briefly made learning curve that the AK had already replaced before full production even began. The transition from wartime need for conservative ammunition supplies to post war infrastructure changing into a surplus machine also would change the mindset. These were new days, the SKS was just clinging a little more towards the old vs. the AK being the new wheel. The entire concept of ground war was changing post WWII, one man with a great weapon suddenly changes things from a mass affront method with bayonets brandished to a hiding behind something and taking out multitudes in short order...and living until the next day.
The SKS seems to be the perfect marriage betwixt practical and devastating. That is why I love the darn things so much.
Where the deer gun meets the oh, dear gun.
All hail Simonov.