In a recent thread on CGN, a forum member claims to have a chrome-lined 1950 gun in his collection. I am doubtful, however I am aware that it isn't entirely impossible -- however improbable it would seem. From time to time over the past 7 or 8 years I have encountered claims of Soviets re-barreling sks45's during refurbishment. In that time, however, I haven't seen any definitive proof that this ever happened.
It seems as if the entire process would overlly labor intensive, and that most practical means of addressing barrels too worn to return to service, would be simply tossing the entire barreled action into the scrap heap and putting the rest of the rifle back into service as replacement parts.
What definitice evidence -- if any -- is there that the Soviets re-placed barrels on the sks45?
QuoteWhat definitice evidence -- if any -- is there that the Soviets re-placed barrels on the sks45?
Doubt there is any, but I dont think it would be much trouble to bust off an old barrel and slap on a new one. The receiver is a highly milled component that would be regarded as valuable so long as its not broken. Especially a non chrome barrel, I imagine pitted or otherwise un-serviceable 49/50 barrels having a much more likelihood of being replaced.
I got nothin Boris. 97% of the photos I have are in the stock, so no help from the alignment marks and barrel match #'s. I'm very wary of any internet poster's ability to differentiate chrome vs non-chrome lined barrels too. You have to physically hold and check a few hundred guns before you'd be able to make any kind of determination I'd think.
As for the practicality of it, i dont see why it wouldnt be a standard part of the refurb process to replace worn and pitted barrels. They took the time to XXX stocks, grind and restamp numbers off mags and trigger groups, and to black bbq paint the bolts, carriers, and receivers. I don't think barrel swaps to get a near new gun would be too much of a task. As far as i know, the barrels didn't change outer dimensions, so all the RSBs, gas blocks, and FSBs would be reused, eliminating the need to go searching for an early style gas block or a late RSB for any particular rebarrel.
I've got no proof they did this, but I generally dont see swapped or mismatched RSB, gas block, or FSBs on Russian guns. This is how I always reconciled it in my mind. dntknw1
What lead to this query was the claim of a 1950 dated gun with an early bolt assembly AND a replacement chrome-lined barrel.
I struck me as particularly odd that an arsenal would put in the effort to refurb a rifle with the early bolt and carrier design. It would make more sense (to me) if it were a replacement barrel on a 1950 gun with the type2 bolt design.
Also the gun in question came through one of the Canadian distributors. Which has me considering the possibility that the dated cover is a replacement and that the rifle is in fact just a 1951 gun with chrome barrel and a early firing pin-- which also sounds weird.
Quote from: Loose}{Cannon on November 24, 2017, 11:20:48 AM
QuoteWhat definitice evidence -- if any -- is there that the Soviets re-placed barrels on the sks45?
Doubt there is any, but I dont think it would be much trouble to bust off an old barrel and slap on a new one. The receiver is a highly milled component that would be regarded as valuable so long as its not broken. Especially a non chrome barrel, I imagine pitted or otherwise un-serviceable 49/50 barrels having a much more likelihood of being replaced.
I would also tend to agree with this.... many nations were known to replace worn barrels and reuse the receiver and the rest that met their guidelines.. Finland, France, Switzerland, Britain, even the United States, plus others done this. Finland was huge in this type of operation on captured Mosins, 99% of Finnish Mosins are all Russian receivers, they just rebarreled with their barrels. Why chuck a perfectly good labor intensive receiver that meets/exceeds all criteria when you could throw a new barrel on it for maybe a tenth of the cost, and a tenth of the time of building a new weapon, and just have a fully viable rebuilt weapon ready for action. When your fully equipped to do it in a massive rebuild shop, it's not that hard.
MAS36s, Enfield rifles, 1903's, 1917 Enfield, K31s, Garands, M1 Carbines all got rebarreled... I"m sure even Sweden rebarreled their Mauser given how close they checked bores.
I have a few issues that I try wrap my head around.
I can see rebarreling, why not? What I don't get is changing barrel components around, without skipping to the chase and replacing the whole assembly. For instance, replacing the spiker small stock ferrule on a 49 to meet blade bayonet and stock standards. If recycling was a paramount priority...we should also see '55s with the occasional 90 or 45 degree gas block. From my reading I am beginning to surmise that it wasn't a shift changeover at Tula and suddenly they exclusively made blades. More and more of the stuff coming up in Canada makes me think that blade and spikes had a concurrent period in later 49 and early 50. I speculate it was probably sometime mid Decemberish that it may have began to transform....what would really be nice to isolate is when the receiver covers became stamped vs engraved....
There is enough evidence from what I have found in the 49 dept. on Russian sites to make me suspect rebarrelling didn't happen. What I have seen refurbished in that era at most have replacement laminate stocks, while retaining all of the original features...even the spikes. Beyond that, they appear to be unfettered. I have not seen a spiker refurb that has even a 45 degree block...I did not see any from 49 that still had original bluing...indicating pretty drastic refurb with the BBQ dip....I feel for the poor dumb bastard that had to fit a laminate to a few of them.
Considering that for the majority of Russian SKS manufacture, they were in a rebuilding period...and the SKS was always a bridesmaid, but never the bride. I find it pretty cool that they seemed to be still working out some kinks on it for as long as they did. (bad gas block innuendo intended...hope you got it)
I can totally see them unbarreling and reusing receivers but totally upgrading them in the process....and scrubbing them. They liked to scrub things and reserial. I don't think they did many of the early ones, simply because there weren't many that needed rearsenaling. It would not be hard to upgrade an early receiver to accept the updated take down lever though...some 49/50 receivers may be in the melee of refurbed guns. When you don't see evidence of random early parts used on other refurbs it kind of makes you question just what they would do.
I do believe there were some minor variances between 49 and early 50 even though. Fitting an early 50 cover to my 49/50whathaveyouSKS was a bear of a job, whereas finding a replacement 49 cover took little more than reblueing the scrubbed serial that was dabbed into the BBQ pit for a sec. Fitting a known early 50 trigger group to my receiver was also an unexpected surprise. There may be enough variance in them for it to not be worth the effort to rebarrel. How much could one use/neglect a gun to require a new barrel within two years? Perhaps the OP's gun in reference was just an early trial in chroming? It falls into the last evolution time frame that the SKS ever had until the Chinese started cost cutting measures....and the Albanians just got all wacky with it. :)
All this being said, one day away from my 11 month anniversary of really reading into early Russians much at all. My first and only...so far....just happens to fit into the weird few months these transformed into what essentially was the cookie cutter SKS for many years and nations to come.
My vote is, of course they re-barrelled them. There are lots of ways to wreck a barrel without shooting it out.
Justin, I think you and I are looking at this from totally different ends of the spectrum. To reuse a '49 receiver, you simply have to have an early RSB as a late one will simply not fit. Because of this, and because you don't see early FSBs and curved gas blocks on early receiver guns (at least I don't), my thought is that when they rebarreled an SKS, they reused 100% of the components attached to the barrel. With the barrel off already, it wouldn't be much of a task to pull the FSB, stock ferrule, gas block, and RSB and then refit them all together onto the new barrel after it's indexed onto the receiver. I would think it very rare that the majority of these barrel mounted components wouldn't be reusable. Voila, you have a gun with a new barrel and mostly original components. Then they fit everything else according to what the gun needs, with the exception being blade bayos being used with early spike stock ferrules (and we've seen them weld the reinforcing plug on these to avoid the cleaning rod hole weakening the whole setup.)
The only things I see heavy evidence of being swapped for non like year hardware are things like rear sight leafs, receiver covers, magazines and the like. As you've noted, this probably took some fitting, but being in a refurb shop, they could grind to their hearts content and at the end of the day, if they had a working firearm that's all that mattered.
QuoteI struck me as particularly odd that an arsenal would put in the effort to refurb a rifle with the early bolt and carrier design. It would make more sense (to me) if it were a replacement barrel on a 1950 gun with the type2 bolt design.
Yet many refurbs are in the country with spring loaded fp bolts.
Quote from: Loose}{Cannon on November 24, 2017, 06:45:14 PM
QuoteI struck me as particularly odd that an arsenal would put in the effort to refurb a rifle with the early bolt and carrier design. It would make more sense (to me) if it were a replacement barrel on a 1950 gun with the type2 bolt design.
Yet many refurbs are in the country with spring loaded fp bolts.
But with chrome lined barrels?
This would present the argument that some percentage of "all original,""as-issued," "non refurbs" are actually rebarreled guns.
I'm still seems that shot-out, irreplaceable sks barrels more likely accompanied their receivers into the scrap heap and back into the smelter.
Is there any know evidence of arsenal rebarreling on any of the sks variants? Seems like a rebarreling require some form stamp somewhere on the barrel or receiver, no?
Ok.. how many shot out, corroded Yugo barrels are seen vs. how worn are the receivers on the same rifle? If it would pass headspace test, hardness and what ever random checks they did, why not just change out the barrel?
Which is easier to manufacture a receiver or barrel? Time is money, time to rebarrel vs time to build a whole new weapon, plus figure in materials.
A spring loaded firing pin is a basic item, that a field armorer could fix if a problem arose. If it passed muster in the refurb shop, it will go till it fails. Russia was going to do it as cheap as possible to arm as many as possible, quickly. Besidese time their main battle weapon had became the Ak... The SKS was kept more for guards, rear line troops, training, supplying other Warsaw pact members with arms, etc.
How often is a Russian SKS ever seen with a barrel like a Yugoslavian, worn/corroded slam the "f" out... I've never heard my Russian has almost zero rifling... My Russian bore is so pitted from corrosion.. On Yugoslavian nonchrome bored that's common. Most Russians are toted as bright and shiney, so this leaves one of 3 options...
1. Everybody lies about their bore
2. They were never shot much
3. Russia rebarreled and updated worn ones with chrome bores
Maybe 4.... Russia redid a bunch for import... A new refurb sells for more than a used highly worn beater... Commie business thinking.. chuckles1
But what do I know... rofl2
Still waiting for evidence. Nearly a decade since I first heard of rebarreled sks's and I still havent seen a photograph of one.
Still seems more likely that a worn out bore ends up in the smelter along with the receiver its attached to. The rest of the rifle is then parted out-- a very plausible explanation for the abundance of mismatched/ forcematched triggers, mags, covers, and stocks that ended up refurbished guns.
Replacing and/or upgrading stocks, triggers, magazines, and other parts are straightforward, and simplistic procedures (most of us can do this ourselves) in comparison to the time consuming tasks involved in replacing worn out barrels. Impossible? No. Impractical? IMO, absolutely yes.
Quote from: Boris Badinov on November 24, 2017, 07:05:06 PM
Is there any know evidence of arsenal rebarreling on any of the sks variants? Seems like a rebarreling require some form stamp somewhere on the barrel or receiver, no?
TRB in Bosnia rebarreled and sold those oddball M59/66s. They were doing a total rebuild. The B-10 and B-16 models...that at first were sold as M-59s. They were advertised as.. "rebuilt, cleaned and refinished utilizing new unissued barrels by TRB"
So it has happened I guess..if what they say is true.. I have never seen one in person.
Why would it require a stamp.. if done 50-60 years ago, they were planning on WWIII... Not making money off their enemy with surplus junk 30 years later after it was done.
Quote from: Boris Badinov on November 24, 2017, 08:38:32 PM
Replacing and/or upgrading stocks, triggers, magazines, and other parts are straightforward, and simplistic procedures (most of us can do this ourselves) in comparison to the time consuming tasks involved in replacing worn out barrels. Impossible? No. Impractical? IMO, absolutely yes.
See, I don't think that a repair arsenal with all the proper tooling would have that tough of a time replacing worn barrels. They'd have presses and jigs to pull everything off on that old barrel in no time. All the proper sized vises and spanner wrenches to pull barrels off easily too. The headspacing would be the hardest thing to do I'd think.
You're 100% right about not seeing any evidence. I haven't either, but again, it's not a feature that's captured very well in photographs and I wouldn't trust many SKS owners to be able to differentiate a chrome vs non chromed barrel.
This is a great discussion, as it makes us think! Perhaps there is indeed a 'rebarrel' stamp that they used that we simply haven't deciphered yet. There are lots of common marks on barrel lugs that could mean anything. It might be worth trying to look for a pattern on heavy 'furb guns...
thumb1
What exactly would a 'sign' of re-barrel be?
Perhaps a dif font on the corresponding fitment numbers.....
I agree with RM, if some weirdo named Cannon an bust off components and twist off barrels..... Im sure the russians could do it pretty darn quick! Can also headspace one in a matter of a few minutes as well.
Quote from: Greasemonkey on November 24, 2017, 09:04:19 PM
Why would it require a stamp.. if done 50-60 years ago, they were planning on WWIII... Not making money off their enemy with surplus junk 30 years later after it was done.
Why are there any stamps on any Soviet SKS's or any military gun for that matter?
They stamp them for future armorers. Like the log books that came with 59/66's, they are a record for those making future repairs to refer to whem making a determination on whether a part will remain, be repaired or replaced.
Regarding the Yugoslavian sks: with no chrome lining I would expect that the Yugoslavian variants would be the most likely variants on which to find rebarreled actions.
But they Yugoslavians were operating under very different circumstances than the Soviets and with far less access to vital resources and infrastructure. Post war USSR had a massive horizontal and vertical industrial complex-- recycling receivers to add new barrels is time consuming and impractical.
Ergo, the abundance of mismatched/forcmatched parts and stocks on Soviet refurbs. To the smelter with the labor intensive, shot out, barreled receivers and to the recycling bin with the rest of the parts and the stocks. We've all seen or own 45's with xxxx'd out stocks-- did those barreled actions 1) end up in another force matched stock along with all the matching parts? Or 2). Is it more likely that the barreled actions were tossed and the stocks and parts ended up forcematched or scrubbed and restamped on refurbished guns? The latter seems far more likely (for the Soviet guns) to me.
QuoteWhy are there any stamps on any Soviet SKS's or any military gun for that matter?
Fitment numbers, quality control inspectors stamps, lot/heat numbers, Provisional black powder proof, Final black powder proof, Point of aim proof, Concentric "00" Accuracy proof...... all kinds of stamps, but none of them have to do with telling a rework tech what to do with it. Iffin a fubared barrel is coming off .... what purpose does a stamp serve?
Crazy thought inbound....
If that gun on CGN does indeed have a chrome bore.... it was replaced. Does it have any 'new' or otherwise not seen before mystery stamp on the lug or forward area of the receiver? Im guessing it does not.... which would tell me there is no special stamp on a rebarrel.
I look at it who cares what the part was it's last time in a refurb shop. If it's close or beyond spec now, replace it. What it was... has no bearing on what it is now.
And who is to say the mismatched parts we see didn't come from truly broken rifles, broken receiver or something else. They scrap it out and keep the good bits.
How does one know the mark is not there.. do you or anyone else know exactly what every single Russian military stamp is and have verification of such proof. The stamp may well be there.....but no one knows exactly which one it is. And getting a Russian to come up off such information would be like China coming off their information....
And again.... why have no Russians been found with worn, pitted or nasty bores? Especially non chrome early ones?
The way I look at it, the rearsenal tech wasn't working with a complete gun.
If this were the case, then when the barreled action ended up on in the rearmorer's hands, he (or she) had to determine the re-serviceablity of the weapon without being able to test for function. The test for the barreled action was simple: Visual inspection, some basic spec measurments, and slugging the barrel. If the barrel or receiver was worn or corroded, or some measurement out of spec, then to the heap for smelting went the pair. With no way to test for function the re-serviceablity of the entire barreled action would have depended on the results of the inspection alone.
What would a re-barreling stamp look like? No idea. But since the soviets stamped for umpteen different procedures, rebarreling would seem to be one procedure that would definitely require a stamp of some sort.
Quote from: running-man on November 24, 2017, 09:26:02 PM
Quote from: Boris Badinov on November 24, 2017, 08:38:32 PM
Replacing and/or upgrading stocks, triggers, magazines, and other parts are straightforward, and simplistic procedures (most of us can do this ourselves) in comparison to the time consuming tasks involved in replacing worn out barrels. Impossible? No. Impractical? IMO, absolutely yes.
See, I don't think that a repair arsenal with all the proper tooling would have that tough of a time replacing worn barrels. They'd have presses and jigs to pull everything off on that old barrel in no time. All the proper sized vises and spanner wrenches to pull barrels off easily too. The headspacing would be the hardest thing to do I'd think.
You're 100% right about not seeing any evidence. I haven't either, but again, it's not a feature that's captured very well in photographs and I wouldn't trust many SKS owners to be able to differentiate a chrome vs non chromed barrel.
This is a great discussion, as it makes us think! Perhaps there is indeed a 'rebarrel' stamp that they used that we simply haven't deciphered yet. There are lots of common marks on barrel lugs that could mean anything. It might be worth trying to look for a pattern on heavy 'furb guns...
thumb1
I Totally agree.
What's so hard about a rebarrel job for a refurb shop to do? Headspace.. they have head spaced hundreds, if not thousands. Thread the old one off, it will probably be close, set it up, drill a gas port in the correct place. The install the rear sight, barrel ferral and gas block, then front sight.
Maybe.... And I'm spitballing an idea..... Maybe, this is what the numbers on the receiver and barrel might mean..maybe they are all slightly different specs on each, maybe a .001 or .0005 difference in each. Maybe those are more than just a barrel/receiver assembly number. Each number could corospond to a certain measurement. So they go get a barrel with a number that matches what on the receiver, torque it down.. easy to put headspace in spec.
This is something that has never made much sense.. used by most makers...but no real rhyme or reason as to why....exactly. and why numbers don't exceed a certain number.
One never knows...
Quoterebarreling would seem to be one procedure that would definitely require a stamp of some sort.
Then I guess I wanna see this 'rebarrel' stamp. :)
We already have many known refurb marks.... Why would they stamp every part replaced with a special 'replaced' stamp? They dont. There are no 'replaced' stamps on FCGs, carriers, bolts, bayos, covers, mags...... nada. The refurb mark is the rebarrel (and whatever else it got) stamp.
QuoteThe way I look at it, the rearsenal tech wasn't working with a complete gun.
But yet most refurbs still have their original non scrubbed parts after refurb....refurbs are not 100% franken guns. They had to be keeping parts together at some level.
from CGN
QuoteI will say that the unpaired #2 that bobdbldr indentifies on the left side of his receiver is very intriguing, as the matched pair of numbers on the left receiver flat and barrel shank are known to be an indication of an original matching barreled receiver.
Dont we have dif fonts on receivers and barrels.... same gun? I think RM just posted this somewhere....
If these numbers indicate what 'I' think they indicate...... its a seating depth indicator and the numbers were stamped prior to assembly. Match a 33 with a 33.... same insertion depth into the receiver as a 22 with a 22. This would be vital in order to minimize headspacing tolerance.
https://clone.sks-files.com/index.php?topic=3590.msg41242#msg41242
Quote from: Loose}{Cannon on October 30, 2017, 09:21:27 PM
This whole paired numbers bs has irritated me since day 1. Why do it in the first place?? Were they intending to later strip off all the barrels, mix them up, then put them back together again for craps and giggles??
The only reason I would think to remove the barrel is to replace it, and in that scenario you would be tossing the barrel so you dont even need a number on it.
My current theory of choice is that these numbers are fitment numbers used in the same manor as the barrel numbers for (what we think) to match up size wise to the RSB, gas block, stock ferrule, and FSB.
Basically it would represent a dimension of the threaded barrel socket of the receiver and visa/versa the threaded male shank and lug of the barrel. (lets say) the numbers represent a fraction of a millimeter. In this case the highest number observed would be .36mm which is just about .014 thousands of an inch. I think its entirely possible to have a maximum tolerance variation across production of .014" or less.
That being said when a worker milled a barrel shank, a dimension was measured. If the perfect target size is say 40mm and its over that number by .09mm .... its marked with a 9.
You do the same thing with the receiver, you can literally have barrels and receivers marked in bins ready to pull for a perfect match. I would assume this measurement would be the barrel shank to mating flat so that the pair will index on the first attempt rather then having a worker failing to index barrels all day.
Quote from: Loose}{Cannon on October 30, 2017, 09:33:00 PM
Put it this way.... RM may back me up on this one.
If you DONT do this during the production...
A: You have a high failure rate of indexing barrels
B: You have to mill the receiver face on nearly EVERY single receiver until index is achieved.
If B, welp.. then you end up with a LARGE tolerance range from gun to gun on the back end of the bolt requiring major differences in length for headspacing.... more time and milling and a VERY LOW probability of interchangeability.
No.... you do as I described in my previous post and avoid ALL of that.
Quote from: Loose}{Cannon on October 30, 2017, 09:44:31 PM
You absolutely HAVE to devise a way to properly index lug flats and achieve consistent insertion depth into the receiver to ultimately save time, minimize drastic head spacing lengths of the bolt, achieve interchangeability, or at least reduce adjusting requirements of the bolt to head space.
Another explanation for the paired number that makes sense to me:
Prior to final assembly, bare-barrels were fully seated into the receivers, the alignment hash mark was stamped. Then--before removing the barrel to attach the ferrule, gas-port and front and rear sight blocks-- the matching numbers were stamped to assure that the now fitted pair of barrel and receiver were re-united when the barrel was reinserted for final assembly.
Hey Boris,
I always assumed that the stocks were XXX'd and replaced on different guns because that single part is the most time intensive part on the SKS and as such it was impractical to replace the same stock on the same rifle after a refurb. By time intensive, I mean that it took many many hours, perhaps even days for all the processes to take place and for things to dry and cure properly before it could be handled and reinstalled.
Pull a stock off the rifle, remove all the metal components, strip it/sand it, hit it with at least one coat of shellac if not several with a fair amount of drying time in between, assign it to a rifle, fit the crosssbolt to the receiver correctly, sand internally as needed, check that the bayo cut is correct, and finally XXX and/or stamp it with the correct serial number. I'd guess that many stocks were cracked and unsalvageable...off to the furnaces with those...which would mean there would be an equal number of blank hardwood and two crossbolt amber laminates on various guns indicating 'new' stocks coming into the equation.
I hadn't considered that perhaps the stocks are coming off guns that no longer exist...that's an interesting thought. Would it be likely that stocks would outlast barrels though? I have a hard time wrapping my head around that one, would a shot out gun have decent wood on it? Maybe I'm being unduly influenced by the Sino-banians and how nice the bores are (albeit they are all chrome lined) and how poor (in many cases) the wood looks. Good stuff though, I'm diggin' it!
Quote from: Boris Badinov on November 24, 2017, 11:09:07 PM
Another explanation for the paired number that makes sense to me:
Prior to final assembly, bare-barrels were fully seated into the receivers, the alignment hash mark was stamped. Then--before removing the barrel to attach the ferrule, gas-port and front and rear sight blocks-- the matching numbers were stamped to assure that the now fitted pair of barrel and receiver were re-united when the barrel was reinserted for final assembly.
Two things..
#1 You have to install, index, drill, and pin the RSB, FSB, and gas block while in barreled receiver state. Why? Because the RSB houses the OP-rod which has to be perfectly indexed to the.... receiver. The gas-block then has to align with the RSB, and so then does the FSB!
#2 The lugs have a 'flat' on the top and bottom right? Given machining length tolerance variations from lug face to chamber face, and receiver front to receiver headspacing lug. You will NOT just be able to screw on any random barrel to random receiver and have the upper/lower lug flats index square to the receiver. You HAVE to have a controlled measurement/number system to mate barrels to receivers without executive over/under rotational indexing.
I personally fitted a yugo barrel to a yugo receiver with non matching numbers. The flats did not index and the front face of the receiver had to be milled in order to rotate the barrel another 120 degrees. This also seated the barrel further into the receiver meaning ..... I had to do a good bit of material removal of the bottom rear of the bolt to headspace. This is the kinda crap im talking about that is a HUGE no-no in mass production.
Hell, I used to do all kinds of choppin and swapin on SKSs back in the day.... I fitted other barrels to non matching receivers on chinese aswell. Im tellin ya.... .005 difference from lug mating face to chamber face or +/- .005 on the receiver mating face length. You will not just screw that barrel in and have it index.
These numbers are a measurement control system for proper indexing and headspacing.
Do this....
Everyone go get out their russian sks and start looking for numbers on the barrel that corresponds to numbers on the RSB, FSB, and gasblock.
If anyone tells to their FSB has a #1 stamped on it so its more accurate then a #2 or a #3..... Kick em in the ding ding.
I was a machinist in a past life. Due to the human factor, machine calibration, tool wear etc you WILL have slightly larger or smaller IDs of components and ODs of the barrel journal locations where they reside. You do not try 32 RSBs onto a barrel until you find one that fits. You measure each ID and OD and mark them according to their measurements. Example: RSB IDs measuring .726 to .730 are marked with a #1, .731 to .735 marked with a #2... So on and so forth. These parts go into a bin separated by size #. A worker assembling said components to the barrel will observe the OD measurement # stamped on the barrel near the RSB location and select the corresponding RSB from a bin of the same number.
Proper fit everytime.... No guessing.
Why do I post this? Because an even more crucial component fitment requiring a similar system is the barrel/receiver. These numbers are part of this process.
Yugoslavia did replace barrels at refurb. This is why refurbs, when supplied with a new log book, the book was empty. It was essentially new again, no issues, no wear. As the weapon entered service and got used, and inspected, parts replaced the book was filled out. They used the log book for the life of the barrel or complete weapon, which ever came first.
Per the documents shown here:
https://clone.sks-files.com/index.php?topic=1491.0
Did they use special stamps? Saying they are different than Russia is true, but in the end they were a communist nation, broke, scared and Russia would have stomped a hole in them. Up until Yugoslavia made the SKS, they were pretty much Mauser, they got all the details from Russia, like they did for the Tokarev. I'm sure Russia set them up on both how to build and refurb, the log books were like the M59/66, a Yugoslavian design. Yugoslavia was kind of more like the Czech Republic, did possibly the minimum of what Russia said, used the calibers set forth by the Warsaw pact and liked to tinker and be original.
So.. modern day Bosnia and the former old school Yugoslavian military did change out barrels.
Maybe cause there was no chrome, they had to rebarrel all the time.... :o rofl2
And what is the explanation for the alignment hash mark?
There would seem to be no reason for it other than to re-align the barrel and receiver for a second time -- which would indicate that the barrel and receiver are separated after initial seating and indexing.
I will point out that no one of us knows for certain that exact order of operations for the assembly of the Soviet SKS. But that hash mark is on all of my rifles, Yugo, Romy, Soviet and Chinese.
I see no reason for the cross-national persistence of the alignment hash mark other than to RE-align the barrel and receiver after they have been separated after initial seating/indexing/head-spacing.
This would make numeric pairing of the barrel and receiver crucial to ensuring that matched barrel/receiver pairs were reunited once rejoined. Hence the hash mark regularly appearing between the paired numbers: they are a triplet set:
Digits--hashmark--digits.
Quote from: Loose}{Cannon on November 25, 2017, 12:31:00 AM
I was a machinist in a past life.
Did you work machining, hardened Chrom-Moly Steel? Or with softer, more malleable metals? And in the production that requires as high a degree of precision as the manufacture of firearms? Because the differences are significant.
Not all types of machining are the same. And higher degrees of precision are required for certain purposes and procedures than for others-- for example, inner diameters that differ by one to three thousandths (like the barrel bore) are far more crucial than some outer diameters that can differ by several hundredths.
.
Quote from: Boris Badinov on November 25, 2017, 07:25:17 AM
And what is the explanation for the alignment hash mark?
There would seem to be no reason for it other than to re-align the barrel and receiver for a second time -- which would indicate that the barrel and receiver are separated after initial seating and indexing.
I will point out that no one of us knows for certain that exact order of operations for the assembly of the Soviet SKS. But that hash mark is on all of my rifles, Yugo, Romy, Soviet and Chinese.
I see no reason for the cross-national persistence of the alignment hash mark other than to RE-align the barrel and receiver after they have been separated after initial seating/indexing/head-spacing.
This would make numeric pairing of the barrel and receiver crucial to ensuring that matched barrel/receiver pairs were reunited once rejoined. Hence the hash mark regularly appearing between the paired numbers: they are a triplet set:
Digits--hashmark--digits.
I would tend to agree that the index mark itself would be used in the event a barrel was taken off and reinstalled for some reason. This in no way shape or form is evidence this was done at the factory, yet alone on every sks being assembled. The marks are just a good habit for future reference. Most likely the only time they would be used is by a later smaller outfit if not a field armorer.
The index mark is literally nothing more then a reference point "if" the need arises. I don't know just how much machining experience YOU have, but to suggest there be no measurement/numbering system and all barrels just slap on thar and index perfectly is NOT how this works by a long shot.
Could the numbers also be used to keep a barrel and receiver together on a small scale? Sure... Call it two birds one stone, but on a large production scale you would alot more then 1-36. Perhaps something like...... a serial number. thumb1
You look at them thar barrel/component numbers?
I promise to pull all of my Soviet guns from the safe this afternoon/evening.
Promise.
Finally got some decent weather, so I'm gonna try and get a decent 4-5 hour bike ride in be while the sun is out and the windchill isn't hovering near freezing.
Another reason I know the barrel was NOT removed to fit/install/index the barrel components is because the RSB covers the barrel lug flat.... How ya gonna put a wrench on thar?!?!.
While we are at it.... Go ahead and drive out those RSB pins on TWO russians or two chinese, drift them forward to gain access to the lug flats, bust those barrels off and swap them...... See if they index. Be sure to have different numbers on the guns.
Disclaimer: I already know how this will end, but its a good learning experience.
I would just like to point out that it is hazardous to claim outright that any one of us "knows" for certain the order of operation of any given part of a process that none of us were actually a part of.
I spent four years working (and one year as a shop steward) in a large scale industrial fabrication plant. There are many aspects to assembly line production that might seem to be counter-productive and counter-intuitive but which persist nonetheless. And there are any number of ways to explain why these seemingly less efficient apsects remain. None of us "were there."
And outright claims of certainty tend to place a dead end where a dead end might not exist.
...
Moving forward... Another inquiry:
Do we have any indications that might demonstrate that the barrels were blued before or after seating / indexing?
#1 Never have I claimed anything of the sort . I just know for a fact you cannot index a barrel with the RSB in place, and you aint indexing a gasblock and FSB without the RSB attached and indexed FIRST. Don't ask me if the rest of the receiver was assembled prior or after because I couldn't tell ya.
I gave you a fool-proof answer that literally covers every angle of the topic. Don't be mad at me for it, your the one suggesting a receiver is thrown away when a barrel needs replaced and that barrels are fitted and removed dozens of times to find one that indexes or otherwise requires extensive additional milling procedures to make it index leaving you with a large headspace difference from one gun to another.
Its just your/my opinion and which one makes sense is up to the reader.
The argument of 'your wrong because you were not there' is something I would expect to hear from someone having a failing argument.
Quote from: Loose}{Cannon on November 25, 2017, 11:39:38 AM
I just know for a fact you cannot index a barrel with the RSB in place,
....
I agree (?) So, you would have to remove the barrel after indexing to attach and index the RSB?
Perhaps I am misunderstanding what you mean by "indexing"?
I would also like to point out that I am still curious to know what to look for regarding the determination of whether or not a barrel has been replaced or not? I am not arguing that it was impossible or unlikely--though llikely uncommon, even rare. I am only arguing that that rebarreling is impractical -- particularly with the addition of the chrome lined barrels and given the fact that the 1950's was a distinctly "cold" period for Soviet Red Army. Ergo, what need to replace what ain't even being used and abused?
Checking out for the afternoon.
Back this evening.
No offense taken. None intended.
QuoteSo, you would have to remove the barrel after indexing to attach and index the RSB?
No Sir.... Im saying you have to index the barrel to the receiver and leave it there prior to installation of the RSB. You do not have access to the lug flats with the RSB in place. The RSB also has to be rotationally aligned with the receiver OP rod hole and mated flush to the receiver. Not until then can you align and install the gasblock and ultimately the FSB parallel to the bore axis.
They do the same deal with the crossbolts. thumb1
Go look for numbers!
Quote from: Boris Badinov on November 25, 2017, 12:00:46 PM
I would also like to point out that I am still curious to know what to look for regarding the determination of whether or not a barrel has been replaced or not? I am not arguing that it was impossible or unlikely--though llikely uncommon, even rare. I am only arguing that that rebarreling is impractical -- particularly with the addition of the chrome lined barrels and given the fact that the 1950's was a distinctly "cold" period for Soviet Red Army. Ergo, what need to replace what ain't even being used and abused?
Who is to say "when" exactly they were done, any of them, there is no tag that says "refurb completed on 11/13/1956, or 10/31/1967". Like the unknown many thousands of Mausers they refurbed captured in WWII. They could have been done in the 1960's, maybe as late as the 1970's. Look at all that happened say between 1955 and say 1975. Cuba, Vietnam, it was a busy time. They could have started prepping and stock piling weapons for WWIII.. rebuilding loaner weaponry for Communist satellite nations to use Or... like modern day Molot, started refurbing these weapons using mass parts over stock of new and old parts for import in to the US and Canada for financial gains and make us argue when they were actually done.
The mating marks can be found on a number of rebarreled weapons m1903, m1917, K31s, MAS36s
QuoteI am only arguing that that rebarreling is impractical
Rebarreling has numerous benefits over building a totally new firearm, materials saving, adds a lower cost per unit which goes hand in hand with labor savings, less down time in the shop equals greater time a troop is armed, ready for action, allows for an easier parts logistics. It can, in the case of France, allow for incremental small upgrades and changes, such as the counter bore on the MAS36 barrel, which early rifles did not have. It can give an indication of mean time before failure for given use to help justify use of repaired rifle vs. upgrading to another type. A rifle that breaks is of no use to a military.
If it's so impractical... Why would Spain for example, totally rebarrel M1916 and M1943 Mausers... and produce the FR 7 and FR 8, Why would Brazil rebarrel m1908 Mausers and make a M1908/34... rebarreling rifles makes sense, again..... it happened right here in the US... a Winchester M1917 with a Remington barrel, An IBM M1 Carbine with a US Postalmeter barrel. Uncle Sam didn't throw a Garand receiver away cause the bore was blown out, he didn't smelt a M1903 receiver cause the rifling was gone. Does a Garand set up easier than a SKS...a Mauser still needs to be headspaced, the M1917 needs to be headspaced. But yet, they still rebarreled.
Britain FTR Enfieild rifles, get them back on the battle field. Finlands military, almost everything they had was Russian captured property, hundreds of thousands of rifles of Tula and Izhevsk decent, mostly all rebarreled in Finland with VKT, Sako, and Tikka made barrels and the reused receivers turned against their creators.
If rebarreling was so impractical.... many militarys would disagree.. everyone did it..
Quote from: running-man on November 24, 2017, 11:14:23 PM
Hey Boris,
Would it be likely that stocks would outlast barrels though? .. would a shot out gun have decent wood on it?
Maybe not, but the one Ivan rested up against the BMP while he was taking a leak, that then drove off and crushed the fsb/bayo/barrel probably did.
There are so many reasons for something to end up at refurbish its impossible to list.
I have learned today that I will never break down an SKS that far....and based on how impractical it is to do....I wonder how common a practice rebarreling could have been. It really doesn't seem to be worth the trouble. Considering the brief period they were actively manufactured and the relatively 'cold' period that it was...I honestly cannot see them requiring service to that degree at all...ever.
In this case, I wonder if they tried chroming on leftover parts perhaps? It does seem most likely they would do that immediately after rifling though...but based on the surface prep they did on the barreled receivers before BBQing them...among other parts....it wouldn't shock me if they could do it after partial assembly.
Perhaps something considered for a time at refurb was chroming barreled receivers? If it was overly labor intensive or just difficult to effectively do...it may have been a very short time they did it.
I have absolutely no basis to speculate upon though...you guys are far more educated on the subject. I totally didn't consider having to remove the RSB in order to even begin unbarreling....and the indexing sounds like a major PITA.
It seems to me the robust nature of the SKS would require little to maintain, it seems as if rust proofing for storage was the main goal of refurbs anyway...the stocks seem to be the only questionable portion of them....stupid wood's lack of being metal and all. I can see older weapons being used in wars and conflicts coming home and perhaps being extensively refurbished if a new replacement weapon had not recently been adopted. At the time Russia had two...and the SKS obviously wasn't the winner. Elegance didn't win over cheap easy mass production in the end...it seems a little off to think they would put a whole lot of effort into refurbishing an SKS to the point of rebarreling unless it was an experiment, or busy work...perhaps training purposes even? Maybe Sergi Pyle's first offense warranted a year in a refurb plant...second was a gulag, third was Siberia. :o
As time moves on and we evolve into a more modern disposable world, and the lack of truly heavy use of the SKS during it's cold war existence the refurbing of these seems less than necessary...considering the massive amount of them on hand, not being the primary weapon, and not being involved in an active heavy combat situation before they were mothballed....the extent of refurbing they did seems insane to me.
I vote this thread as November post of the month....very interesting discussion. :)
No need to make/maintain as many as possible? No need to arm warsaw nations? :o
Mother russia not utilize all serviceable parts? :o
Its a wonder they refurbed guns to begin with!
Justin.. what numbers you find on barrel and where?
https://youtu.be/KMjYNKED0U0
Gotta try get the bum out of my gun room before my daughter comes home and kills him....the 49/50 is sitting here awaiting disassembly...but I only have a couple hours to get a battery under his hood and a tire on his rim...send his stupid ass off to California and prevent a crime scene.
BRB
Just got back.
Did 52 miles on the bike -- it was a beautiful day out so I had to take advantage of it and work of the Turkey, stuffin, pie etc. I also ended up in a 3' deep, sludge filled ditch that, covered with leaves, looked like solid ground. The kind of sludge that smells like sewage. But the ride made it worth the sludge because: "Rule number one for surving Zombieland": https://youtu.be/Ci9dCZEF6Mw?t=2s
If I am going to be able to participate further and meaningfully, I'm gonna have to go back through the entire thread and try and wrap my head around points that you've all made -- lots of good ones and plenty to think about.
But right now: I. Am. Beat. Gonna eat leftovers, watch the last two episodes of Stranger Things 2 with my better half, and then crash out. But I will go through my 45's in the morning -- if i don't end up at the range-- and post my findings. along with any new insights or inquiries that come up.
Great thread, gents.
(glad i thought of it. haha. I kid)
goodnight.
Question:
Are top and bottom lug flats machined before or after seating the barrel?
...
The only practical answer I can come up with is that the top and bottom lug flats must be machined after the barrel has been fully seated into the receiver. Because the "top" and "bottom" of the barrel lug cannot be determined (nor the RSB attached and indexed) until the barrel has been fully seated.
If you have a measuring/numbering system to ensure proper indexing, you sure as sheet can have lug flats when installed...I know I did. thumb1
How they put a wrench on thar? Those suckers are ON THERE TIGHT, ask me how I know.
"Must be" nea1
Quote from: Loose}{Cannon on November 25, 2017, 10:10:19 AM
Another reason I know the barrel was NOT removed to fit/install/index the barrel components is because the RSB covers the barrel lug flat.... How ya gonna put a wrench on thar?!?!.
While we are at it.... Go ahead and drive out those RSB pins on TWO russians or two chinese, drift them forward to gain access to the lug flats, bust those barrels off and swap them...... See if they index. Be sure to have different numbers on the guns.
Disclaimer: I already know how this will end, but its a good learning experience.
Ya don't need to have access to the lug flats to remove an sks barrel from the receiver. You simply need the right tools: Put the barrel in a barrel vice, and use an action wrench on the the receiver flats to break the barrel free. Pretty straightforward:
https://youtu.be/H9IehOwCyXU?t=27s
As Larry Potter says, "So, that's how ya pull a barrel. No too difficult if you've got the right tools, but impossible if you don't."
Quote from: Loose}{Cannon on November 26, 2017, 03:20:27 PM
If you have a measuring/numbering system to ensure proper indexing, you sure as sheet can have lug flats when installed...I know I did. thumb1
How they put a wrench on thar? Those suckers are ON THERE TIGHT, ask me how I know.
"Must be" nea1
Not sure I understand the wording. Are you saying the flats are machined before or after seating the barrel?
Ok Boris.... You gonna love this.
If these numbers have anything to do with indexing a threaded barrel and nothing to do with keeping them together with the receiver. Then pinned barrels will NOT have them.
All sksfiles members please report.
Quote from: running-man on November 24, 2017, 11:14:23 PM
Hey Boris,
I always assumed that the stocks were XXX'd and replaced on different guns because that single part is the most time intensive part on the SKS and as such it was impractical to replace the same stock on the same rifle after a refurb. By time intensive, I mean that it took many many hours, perhaps even days for all the processes to take place and for things to dry and cure properly before it could be handled and reinstalled.
Pull a stock off the rifle, remove all the metal components, strip it/sand it, hit it with at least one coat of shellac if not several with a fair amount of drying time in between, assign it to a rifle, fit the crosssbolt to the receiver correctly, sand internally as needed, check that the bayo cut is correct, and finally XXX and/or stamp it with the correct serial number. I'd guess that many stocks were cracked and unsalvageable...off to the furnaces with those...which would mean there would be an equal number of blank hardwood and two crossbolt amber laminates on various guns indicating 'new' stocks coming into the equation.
I hadn't considered that perhaps the stocks are coming off guns that no longer exist...that's an interesting thought. Would it be likely that stocks would outlast barrels though? I have a hard time wrapping my head around that one, would a shot out gun have decent wood on it? Maybe I'm being unduly influenced by the Sino-banians and how nice the bores are (albeit they are all chrome lined) and how poor (in many cases) the wood looks. Good stuff though, I'm diggin' it!
The way I look at it...all scenarios are viable. Without evidence of the process and the level of efficiency and standardization involved, my best guess is that all scenarios are likely true.
Some stocks in great condition were separated from rifles with metal deemed to corroded to reservice. While other stocks required more intensive attention, due to poor condition of the finish.
I have two 45's with stock minor stock repairs, both are also xxxx'd and force matched.
And one of them has a #2 on the FSB.... Never did report on those fitment numberings.... Crossbolts either.
Damn, so now we need to check all SKSs with threaded barrels? I don't recall seeing the numbers and index marks on my Chinese...but now I am intrigued....almost enough to confront the couch surfer that JUST WONT LEAVE. I hate being a nice guy....just as much as I hate not knowing.
Quote from: Loose}{Cannon on November 26, 2017, 03:36:08 PM
And one of them has a #2 on the FSB.... Never did report on those fitment numberings.... Crossbolts either.
I am only one man. I can't do everything at once.
Would you, please, explain the meaning of your statement above. As I don't understand your wording.
Are you saying the flats are machined before or after seating the barrel?
Before.
Otherwise you run the risk of cutting into the receiver face ultimately shortening it, and we would find different measurements from flat to flat especially on other nations. Ironically they are all an exact MM wrench size.... Dont recall what that size is though.
I guess that extractor recess was cut when installed also? nea1
You screw in a barrel with no flats and let it bottom out wherever it wants and cut the flats after.... You also cutting the extractor recess after...
:-\
I will never again **** about the removal of a FSB.
Jebus, I had no idea.
I can see why you aren't cranking the straight pull match grade SKSs out left and right. How much trial and error was involved in mating a barrel to your receiver?
Laff Justin... I just like keeping ole Boris on his heels and toes.
Xtriggerman sent me two steel half circle deals with the same diameter of the barrel to protect it when clamping in the vice and I put a large crescent wrench on the receiver.
I locked it down and plotted where the extractor recess would be, took it out and cut it, torqued it back on the receiver.
Quote from: Loose}{Cannon on November 26, 2017, 03:46:51 PM
Before.
Otherwise you run the risk of cutting into the receiver face ultimately shortening it, and we would find different measurements from flat to flat especially on other nations. Ironically they are all an exact MM wrench size.... Dont recall what that size is though.
Quote from: Loose}{Cannon on November 26, 2017, 03:50:26 PM
I guess that extractor recess was cut when installed also? nea1
You screw in a barrel with no flats and let it bottom out wherever it wants and cut the flats after.... You also cutting the extractor recess after...
Again. Which? Cut the lug flats
before or
after? From the above statements it sounds like you are saying both.
I wlll get the rifles out later tonight (hopefully) and report what I find. Where are the numbers located on the crossbolts?
We had an unexpected visit from non-firearm-friendly guests in town for Thanksgiving.
It was a statement... That if you cut flats on lug while installed, your also cutting the extractor recess installed?
I have never seen deeper mill cuts on the upper and lower of the receiver face... You would think an offset step would be seen from the side if even ONE was cut further then flush by even a few thousands.
I ask again. "If" these numbers are not rated to barrel index sizing etc, what are they for? I don't believe the off/on story because in the factory you would need alot more numbers then 36.... Like a serial number. In addition, iffin your taking off a barrel to replace it..... WTH would you care about a number on it. Its being scrapped! Literally make no sense.
Quote from: Loose}{Cannon on November 26, 2017, 05:52:03 PM
It was a statement... That if you cut flats on lug while installed, your also cutting the extractor recess installed?
I ask again. "If" these numbers are not rated to barrel index sizing etc, what are they for? I don't believe the off/on story because in the factory you would need alot more numbers then 36.... Like a serial number. In addition,
This is what I am referring to regarding definitive claims regarding a process none of us were there to witness. At 250k guns per year, that's a 685 guns per day average. Why would paired number sets of 1-36 be insufficient? This would require only 19 people. Or 8.5 people performing the same task twice for two batches of numerically paired barrels and receivers stamped 1-36.
It's a bold claim that implies an intimate knowledge of the actual production processes employed by the soviets, and the number of people employed by the arsenal performing one specific task within the order of assembly.
Quote from: Loose}{Cannon on November 26, 2017, 05:52:03 PM
In addition, iffin your taking off a barrel to replace it..... WTH would you care about a number on it. Its being scrapped! Literally make no sense.
As I've stated already, I am doubtful about the frequency and practicality of replacing barrels during refurb. I thought I was clear earlier and elsewhere that I believe these numbers are related to assembly not dismantling and replacement.
....
Also: I'm still not clear on what you mean exactly when you refer to barrel "indexing" and head spacing.
Are you referring to aligning the curvature of the barrel bore to the vertical axis of the rifle to improve accuracy?
Or...
Are you referring to the process of incrementally indexing the barrel to seat it within the receiver with the proper head space?
Quote from: Loose}{Cannon on November 26, 2017, 03:27:58 PM
If these numbers have anything to do with indexing a threaded barrel and nothing to do with keeping them together with the receiver. Then pinned barrels will NOT have them.
Dude, my entire POV is that the numbered pairs ARE index specific. I just disagree that they refer to specific measurement. My whole argument is that the paired numbers are stamped so that the indexed pair (barrel and receiver) are reunited after being separated.
Whether they are separated after initial indexing is where I think our disagreement is.
So.. Why would they be separated after indexing? :
To ream the chamber and machine the receiver face. And finally to machine the lug flats before re-installing into the receiver.
....
I do not own any pinned-barrel guns. But, my guess is that they do not have paired barrel receiver numbers.
This is a great thread. Really getting us to think through different scenarios and contemplate the likely from the possibly all the way to the the ludicrous.
We can all step back take a nice deep breath, we're all adults here and there's no need for anyone to take anything said here personally (not that that's happened or would happen, but I'm just trying head off any possible disaster that might be around the corner...I really like this thread!!) dance2 We will possibly never know the answer, as Boris says nobody was there when these were refurbed and we can't determine things in absolutes. We can perhaps determine more likely vs more unlikely with a bit more data though. LC's idea of looking at pinned barrels is a good one. We have to make certain that we don't take data from formerly threaded receivers that were subsequently scrubbed (perhaps not all the way) and converted into pinned barreled receivers. Also, we have to realize that the Chinese and Russians, while they started out in 1956 with approximately the same hardware with very similar stampings, really did have different assembly and refurb setups by the time the pinned barrels rolled around in the ~1970 timeframe.
So LC's comments on the barrel indexing is interesting. I had totally forgotten about the relief cut for the extractor. That's a game changer right there in my opinion, made the little light bulb go on in my head! bouncecool1
So you're not just trying to get one of two flats to the horizontal position when you put a barrel and a receiver together. That's hard enough with many different variations on flat position vs. thread start location. Now that you are trying to clock the extractor relief cut to an exact location, you have quite a few possibilities - 360 of them if you cared about every single degree. Maybe you don't care about every degree though, maybe if you're within 10°, you can make the barrel clock correctly either through additional torque, peening the faces, other tricks we might not even know about etc. So 360°/10° = 36. think1
Additionally, you start at 0° and never get to 360° because 360° = 0° when clocking something. think1
(http://etc.usf.edu/clipart/43000/43036/polar_36-3l_43036_lg.gif)
So 36 units, starting at 0, going to 35 indicating the clocking orientation of the extractor (and by default the flats, flats are always located the same with respect to the extractor on every barrel regardless of anything else) compared to the starting point on the threads. Sound familiar? think1
I'm thinking this is what these numbers truly mean. Not assembly numbers indicating 1 out of 36 units, but the clocking angle of the extractor as it is mated to the receiver. What do you guys think?!
QuoteThey stamp them for future armorers
Quoterebarreling would seem to be one procedure that would definitely require a stamp of some sort.
Quotethe top and bottom lug flats must be machined after the barrel has been fully seated into the receiver
And the mother of all contradictions within the same post.
QuoteThis would require only 19 people. Or 8.5 people performing the same task twice for two batches of numerically paired barrels and receivers stamped 1-36.
It's a bold claim that implies an intimate knowledge of the actual production processes employed by the soviets,
Their called opinions Boris.... Opinions. You have them, and so do I.
Its a bit frustrating and monotonous explaining the same thing over and over and people out right fail to comprehend what your slapping down or blantantly misrepresent what you are saying.
Lets chop up this lastest one for craps and giggle and go from there.
QuoteSo.. Why would they be separated after indexing? :
To ream the chamber and machine the receiver face. And finally to machine the lug flats before re-installing into the receiver.
The chamber has already been reamed. How do I know? Because 36 numbers wouldn't keep hundreds if not thousands of barrels matched to receivers when they are separated for CHROMING..... You would need a much larger number and a bunch of monkeys trying to put the puzzle back together at a later date.
The receiver face.... You take off .001 off that face and your barrel will insert even further into the receiver and you will index an untold number of rotational degrees PAST your index. What comes next? You would then have to machine MORE off the face until you come back around another 300 someodd damn degrees before indexing again. Now what? Welp, now the chamber face insertion depth into the receiver is too deep. What will that cause? For starters, now your taking off THAT much more off the back of the bolt to headspace. Anything else? Yes, now when the RSB is seated flush to the receiver, it also has now moved back which means your magazine mounting tab on the bottom of the RSB will push the mag too far rearward and will not clear the mid receiver tang AND you may have feeding issues.
Machining the lug flats. Welp.... Just how would you know exactly where said flats need to be?
My opinion is simple.
#1. Throwing out the most valuable and tedious component and heart of the rifle because a barrel is bad..... Rediculous
#2. Barrels and receivers milling processes were complete prior to mating and they used a simple numbering system to ensure proper indexing every time without adding all kinds of time consuming additional individualized procedures and throwing repeatability out the window along with consistency and any hope for interchangeability of numerous components.
QuoteSo 36 units, starting at 0, going to 35
Ever seen 0 stamped? I would venture to say 1 through 36 with no 0. thumb1
Otherwise, I love the idea. In fact GM just sent the notion to me a bit ago and I told him its outstanding.
There HAS to be a control for this procedure..... My opinion.
Quote from: Loose}{Cannon on November 26, 2017, 10:08:02 PM
QuoteSo 36 units, starting at 0, going to 35
Ever seen 0 stamped? I would venture to say 1 through 36 with no 0. thumb1
Otherwise, I love the idea. In fact GM just sent the notion to me a bit ago and I told him its outstanding.
There HAS to be a control for this procedure..... My opinion.
Yup, there are absolutely 0-35. The 0's always bothered me....why not start at 1 I always thought. i think what I've mentioned explains it pretty well.
Never seen a 36 in my 17 years of collecting and believe me I've been looking for one higher than 35......
(https://image.ibb.co/bZDDsm/H2069_receiver.jpg)
(https://image.ibb.co/h5EKXm/H2069_left_lug.jpg)
Ah... Ok. I just remembered you stating 36 total numbers and didn't realize it was 0-35 and not 1-36. wink1
Ahh. So...1-36 are the only numbers known to have been stamped in pairs on the left side receiver and barrel flats?
Also, machining the lug flats with the barrel separated from the receiver AFTER indexing = not impossible. The top and bottom lug flats don't have to be perfectly perpendicular to the barrel axis, they only need to be parallel to one another.
Hypothetically, the lug flats could have been machined according to witness marks that were stamped once the barrel and receiver had been fully indexed and seated. We wouldn't be able to see these witness marks because they were removed when the lug flats were machined.
-----------
What RM has illustrated and explained above -- notably with nary an ounce nor one square inch of condescension -- seems entirely plausible IF 1-36 are the limit on stamped pairs. Numbers larger than 36 would make the explanation less likely.
If true, however, it still leaves unexplained the existence of the barrel/receiver alignment hash marks. Which leaves open the possibility that barrelled receivers were separated during assembly and after initial indexing and seating. If 10° is the margin of error for re-seating the barrel, then the hash mark would be an easy reference for RE-attaching a barrel that has been removed from the receiver during initial assembly. Get the hash marks close enough and yer extractor clearance and head space are good to go.
...and from this, one possible indication of a replacement barrel could be the absence of the hash mark on the barrel lug. No?
Correction: 0-35 not 1-36.
No. chuckles1
Remember, RM isn't dealing with shots across his bow so expect his response to be more.... Peaceful?
If the numbers represent what RM describes, then.....
#1. I am right in that they are an indexing control number based off of measurements to ensure proper indexing..... Everytime, and without causing further serious complications.
#2. They are not to keep barrels and receivers together while the factory monkeys "screw" with them all day. Pun intended.
So... likely many "as-issued" "all original" "matching" guns out there have replacement barrels?
Also, still no exlpanation for the alignment wintess mark/hash mark?
And no means of detecting a replacement barrel?
I would think the indexing mark on both the barrel and receiver were stamped prior to installing the barrel on the receiver. If you have a jig, you can make that mark in the same spot on both pieces each and every time. I don't remember seeing much variation in the indexing marks..maybe in total length, but as far as position, they are always 90° to the surface of the receiver where the S/N lies. Marking both prior to installation would mean that the Russian tech assembling things would have to grab a barrel and a receiver, then figure out a way to get the two lines to line up with each other. At that point, the extractor cut and flats would both be exactly where they needed to be. Headspacing would still need checked and possibly tweaked, but that could be done via other parts such as the bolt itself or even the hardened square key that the rear angle of the bolt locks into...
You clock where thread starts, mark the degree, match up the numbers. Its that simple. thumb1
Hold your fire Boris.... Ill let RM explain the procedure in better detail, but for now.
Its nearly impossible to clock the starting position of male or female threads even on the most modern CNC machines yet alone in the 50s.
What your looking at is rotational degrees that are plotted prior to mating of the components. You would mark the witness mark 90° from 12 o'clock and thread the barrel into a jig. This jig would have 360° marks all the way around it in 10° increments from 0 to 35. When you seat the barrel all the way into the threaded jig your witness mark will land on a number. You stamp that number which literally plots the beginning location of the first thread. You do the same on the receiver using a male jig and stamp the number.
You have receivers and barrels on standby numbered 0 through 35 representing the rotational angle of the begging thread. You achieve perfect index every time you match the numbers.
It explains the witness marks, the numbers, and the entire process of how they indexed barrels to receivers.
Case closed.
Yeah, machining threads consistently from part to part in the 50's would have been a nightmare. Even today, if someone wants a precise start point on a part they would tend to threadmill it by driving the helix instead of trying to single point it out on an NC lathe.
So you know something I just thought of (LC probably already assumed this but it wasn't apparent to me until I thought about it for a bit), if the numbers are indeed representing 360°/10°, then it would make sense that if a barrel was changed...the numbers would never be different. If a #15 barrel/receiver combo was shot out and the Russians chose to rebarrel that firearm, they would replace the old #15 barrel with a new #15 barrel. You wouldn't be able to tell at all by looking at that number. think1
Yup, I do like this thread a great deal! thumb1
Exactly.
QuoteIf these numbers indicate what 'I' think they indicate...... its a seating depth indicator and the numbers were stamped prior to assembly. Match a 33 with a 33.... same insertion depth into the receiver as a 22 with a 22. This would be vital in order to minimize headspacing tolerance
.
QuoteYou do the same thing with the receiver, you can literally have barrels and receivers marked in bins ready to pull for a perfect match. I would assume this measurement would be the barrel shank to mating flat so that the pair will index on the first attempt rather then having a worker failing to index barrels all day.
QuoteThese numbers are a measurement control system for proper indexing and headspacing
.
QuoteWhile we are at it.... Go ahead and drive out those RSB pins on TWO russians or two chinese, drift them forward to gain access to the lug flats, bust those barrels off and swap them...... See if they index. Be sure to have different numbers on the guns.
Disclaimer: I already know how this will end, but its a good learning experience.
QuoteIf you have a measuring/numbering system to ensure proper indexing, you sure as sheet can have lug flats when installed
All from the same crazed jackwagon in the same thread. bat1
Quote from: Loose}{Cannon on November 26, 2017, 10:08:02 PM
QuoteSo 36 units, starting at 0, going to 35
Ever seen 0 stamped? I would venture to say 1 through 36 with no 0. thumb1
Otherwise, I love the idea. In fact GM just sent the notion to me a bit ago and I told him its outstanding.
There HAS to be a control for this procedure..... My opinion.
Installing a manual fuel pump in an old Cummins was the inspiration. Gotta time it or it don't run. Threads are like gears, consistent, and results are able to be duplicated over and over. The only change is it's starting point.
And dealing with enough nuts, bolts, studs in over 30 years of wrench pulling, it takes roughly about 10 degrees give or take to engage 2 threaded components enough to where they won't separate with a pull of your hand, you have to reverse or back one out to seperate. Now this is variable due to thread pitch, smaller pitch/fine threads are slightly less, course threads a little more.
Counting the threads will tell you your exact number of turns for seating to contact, this works on any bolt, but, screw jack, puller,. Torque when contact is made between two components will seat it slightly more because your stretching metal,, stressing the threads some, which for given material of known hardess/strength and thread pitch is also predictable. All materials will deform a certain amount, under a certain amount of force which is constant and known. Exceed the known max value and the components become useless.
Which is why torque to yield bolts are so common....stretch, torque to a rated value and turn another 90 degrees. The amount of clamping load is predetermined then, by not by a torque value, but by the amount of predetermined bolt stretch. Also, this is why generally you chuck them if and when removed. Stretch them again, usually they will break, the metal in them has reached the max it can stretch.
I'm sure RM and his engineering back ground can explain it better.. :)
So last night i was totally onboard with this thread....until... i realized that for someone to be able to look at one part and say i need a number X of the other part someone else has to put them on something to figure that out.
So, just because i am slow, are we saying, that a step was taking fresh round barrels, figuring out where the thread starts/how far they go in, marking it, slicing the sides off to fit a wrench?
And something similar for recievers.
Overnight replies have suggested that, but i'm just checking.
For clarification, Reply #81 was me quoting myself. Those are all my own quotes.
Quote from: newchi on November 27, 2017, 08:38:52 AM
So last night i was totally onboard with this thread....until... i realized that for someone to be able to look at one part and say i need a number X of the other part someone else has to put them on something to figure that out.
So, just because i am slow, are we saying, that a step was taking fresh round barrels, figuring out where the thread starts/how far they go in, marking it, slicing the sides off to fit a wrench?
And something similar for recievers.
Overnight replies have suggested that, but i'm just checking.
For something like this to work, the Russians would have to have made up some type of master jig that determined the indexing on a barrel or receiver. The master jig (or duplicates of it) would then be used to identify the index number of every barrel and receiver and that number could be stamped and the components organized into bins. This could be done long before either of those two components were mated together. Two #17s paired together would get you well on your way to a functional firearm as the indexing is taken care of. Press on the barrel components, headspace the bolt and voila you have a barreled receiver w/o a bunch of trial and error fitment.
I see no reason why the flats weren't already on the barrels prior to mating with a receiver. I think LC's argument that if they were cut after being mated to a receiver there would be areas of receiver that get kissed by the endmill is 100% correct. The flats and the extractor cut (and the gas port for that matter) are always located an exact clocking from each other on every single barrel. It's the threads on the lug that are highly variable barrel to barrel and receiver to receiver that must be taken into account.
I have an idea how we can test this hypothesis too. Let's see if it pans out! thumb1
Nuts and bolts time?
Quote from: running-man on November 27, 2017, 12:03:54 PM
I see no reason why the flats weren't already on the barrels prior to mating with a receiver.
Me neither, once you have figured out where the top is going to be then you know where the cuts will have to go.
QuoteI have an idea how we can test this hypothesis too. Let's see if it pans out!
Me too, RM's going to look in the safe for a 0 and an 18 (or other opposites) and take them both apart, switch barrels and show us an sks with the bayo on the top! yahoo1
You mean 0 and 17. ;)
Another note...
When you thread in the barrel, you need to have it stop short of indexing so that the last 10° or so is all torque. I'm confident that when they clocked the threads on the barrel, they advanced the scale on the jig by 10° so that the barrel will stop just shy of indexing and the rest of the way was torqued.
So... If under normal clocking conditions the witness mark would land on say 20 but the scale was advanced so its actually a 19. Thread it into a 20 receiver and it stops 10° shy of index. Torque down the last 10° to witness.... Good to to go. wink1
Going back to the original post with an idea..
QuoteWhat definitice evidence -- if any -- is there that the Soviets re-placed barrels on the sks45?
Has anyone ever seen a counter-bored sks?
I doubt there were any due the the short barrel and x39 cartridge, its no mosin where a inch or two less rifling isnt going to matter much.
So even if a recruit ruined the muzzle by cleaning it wrong every day it was getting changed out.
Quote from: newchi on November 28, 2017, 07:12:22 PM
Going back to the original post with an idea..
QuoteWhat definitice evidence -- if any -- is there that the Soviets re-placed barrels on the sks45?
Has anyone ever seen a counter-bored sks?
I doubt there were any due the the short barrel and x39 cartridge, its no mosin where a inch or two less rifling isnt going to matter much.
So even if a recruit ruined the muzzle by cleaning it wrong every day it was getting changed out.
Or... a worn, pitted, hardly any rifling.. Whats the primary descriptor in a GB auction on a Russian bore... Lets see...RM listed 42 auctions in Sept '17.. lets check half the pool and see what half say..
1. 1951 Russian, The rifling is sharp
2. Russian Tula SKS 1952, bore is mirror bright.
3. Russian Tula 1953r, No description
4. Russian Izhevsk SKS 1954, Bore looks clean
5. Russian SKS 1954 Tula The bore is chrome lined and perfect
6. RUSSIAN SKS 1954 No description
7. Russian SKS Type 45 Mint condition Russian SKS
8. Tula Russian SKS Bore is good and shiny
9. RUSSIAN SKS 7.62X39 BORE IS SHINY W/GOOD RIFLING
10. Bubba Russian good condition..no bore description
11. Bubba Russian same lameo description as above
12. Russian Soviet SKS with 20" barrel having a bright bore
13. Russian SKS 1950 Tula bore is shiny and the muzzle passes the bullet test
14. 1950 Russian No description
15. RUSSIAN SKS TULA 1950 chrome bore is in excellent condition
16. SKS 1951 Tula bore is mirror bright and shiny with sharp rifling
17. Russian 1951 SKS Bore and rifling are good
18. Russian SKS 45, 1951 Bunch of hoopla..no bore description
19. SKS M45 Tular Fat finger keyboard, but no bore description
20. UNISSUED russian SKS bright shiny bore...uhmm...duh
21. Russian SKS 1952 Tula don't think it has been fired since rebuild.. so 2 dollars to a doughnut...it's fricken bright and shiny..RIGHT?
8 no descriptions...and 13 wonderful bright shiny bores..
Does nobody get a bad one, worn one, one thats blowed out, no rifling, sewer bore.... Was there such a thing out of the box during importation?
No chuckles1
I would guess that better than 90% of the 45's being sold online (with a barrel description given)
will come with claims of "shiny," "strong", "mirror-bright", "excellent", "like it has never been fire" etc...
LC-- are you still looking for fsb number stamps?
Quote from: newchi on November 28, 2017, 07:12:22 PM
Going back to the original post with an idea..
Has anyone ever seen a counter-bored sks?
I doubt there were any due the the short barrel and x39 cartridge, its no mosin where a inch or two less rifling isnt going to matter much.
There is no difference in barrel length on an SKS than a M38, M44, M91/59, M91/38 or a Type 53, all including the SKS had 20 1/2 inch barrel length. And the Mosin carbines can be found counter bored like their longer conterparts. I've seen between 3/8 inch to almost 2 inches of counterbore on the carbines, there was no specific set depth, they just removed what was needed. If they did counterbore, I would imagine that missing inch or two wouldn't make a whole lot of difference on an SKS with a 20 1/2 inch barrel....when an Ak47 has a shorter 16 incher, and got by just fine. Biggest thing is it could affect the gas system, maybe by changing bore pressures and what not.
I have never seen a SKS counterbored, come to think of it, I haven't seen a Type 53 Mosin with a counterbore...and there is some really, really rough bores around, but no counterbored ones I've seen.
Like Blicero like to say...... Lets do this!
https://clone.sks-files.com/index.php?topic=3767.msg42059#new