Soviet Re-arsenal re-barreling?

[Loose}{Cannon]

Exactly.

[Loose}{Cannon]

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

.

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.

These numbers are a measurement control system for proper indexing and headspacing

.

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.

If 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.   

[Greasemonkey]

So 36 units, starting at 0, going to 35

Ever seen 0 stamped?   I would venture to say 1 through 36 with no 0.   

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..

[newchi]

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.

[Loose}{Cannon]

For clarification,  Reply #81 was me quoting myself.   Those are all my own quotes.

[running-man]

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! 

[Loose}{Cannon]

Nuts and bolts time? 

[running-man]

Nuts and bolts time?

You bet your bottom dollar! 

[newchi]

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.

I 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!

[Loose}{Cannon]

You mean 0 and 17.   

[Loose}{Cannon]

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. 

[newchi]

Going back to the original post with an idea..

What 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.

[Greasemonkey]

Going back to the original post with an idea..

What 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?

[Loose}{Cannon]

No   

[Boris Badinov]

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?

[Greasemonkey]

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.

[Loose}{Cannon]

Like Blicero like to say......   Lets do this!

http://sks-files.com/index.php?topic=3767.msg42059#new