Sks re-barrel project

[theSKSguy45]

Hey so I posted about my 1950 Tula sks and it’s pretty poor bore. I was wondering if I could get some answers from people. 1st off what torque spec should the barrel be set to? Second I’m planning on ordering headspace gauges but they won’t be in before the swap (hopefully this weekend), is there a way to roughly confirm headspace I could use? This being confirmed by the gauges when they arrive. Thirdly is there any modifications that need to be made to the barrel/receiver to ensure they sit correctly (they both are marked 0 so they should be compatible yes?) or is it simply swapping them out?. Fourth and finally is there anything I may be overlooking that I should address prior to the swap? Thanks

[echo1]

Murray did the test work on the clocking verification. PAX

[Phosphorus32]

It looks like you have a transitional 1950 with a 90° gas block. It’s a shame that the bore is so bad that you decided to change it out.

It looks like what I presume is your donor barrel is from a Chinese with a short lug threaded barrel. I’m not sure if the rest of the barrel profile matches up exactly with an early Russian barrel profile in terms of diameters where all the different sleeved and pinned components attach.

Presumably the Chinese use the same zero mark (top of the clock) for the indexing (clocking) marks (0 through 35) that the Russians did, but I don’t know that for sure. If so, then you’re matching 0-marked barrel and receiver should line up very close to perfect. As far as torque specs, I’m certain that nobody knows for sure what the Russians used, but I imagine a gunsmith could give you an educated guess for a threaded receiver and barrel on a semi-automatic rifle.

[theSKSguy45]

Barrels are prepped all I need to do now is switch them out and press on the barrel components



This gas block has seen better days

[echo1]

No blood? PAX

[theSKSguy45]

Not yet at least. Tried to see if I could cheat the Chinese barrel out with two big crescent wrenches. Not even close, this will be fun.

[theSKSguy45]

Barrels are off and the swap is imminent, going to clean it up good before attempting to set it in place.

[running-man]

Very nice!  What did you finally use to get them loose? (I see a 3' pipe wrench in the background of one of the pics!  )

[theSKSguy45]

Initially I tried putting the receiver in a vice and using a crescent wrench. That ended up rounding the corners making any further attempts of removal near impossible. After trying to use that pipe wrench on the junk barrel unsuccessfully I relieved material around the face of the junk barrel being sure not to damage the receiver. I did the same with the donor barrel but removed material from the receiver instead.

I had gone into this project using this video as a guide https://youtu.be/8mwr5lnKC4Y?si=pViGhdJ3unZibIZa in my newly gained experience that barrel had to have been removed and re-installed prior to filming because I used an amount of force well in excess of that with no success.

The end result was one junk barrel and one junk receiver. I’m reasonably certain if I had the proper tooling I could have avoided this predicament but that’s how you learn I suppose. Kinda why I wanted to try it on this rifle as I’m only $150 in on.

We will see how difficult installing the new barrel will be as the fit appears slightly tighter between the new barrel and old receiver.

Perhaps rethinking my approach will be necessary


The relief cuts I made to the old barrel.

[Greasemonkey]

Possibly some heat and soak.. not heat it red... but... warm it to 300-350 degrees well before metal color change, you dont want to change the hardness or previous heat treatment, so keep it low.. When I was a truck/heavy equipment mechanic.. common practice was to spit on bearings and such, when the spit bubbled and bounced.. it was right.. time to install. There are temp crayons that the mark vanishes at the correct temp for this same job. Soaking with or dunking it in oil while heated can help draw in the lubricant to the threads, many things work, diesel, PB Blaster, Free All, 50/50 mix of acetone/ATF, even regular candle wax. sometimes it might take a few cycles to do it, but usually it will help..There have also been times... dry ice was used to loosen things.. I've used it on cylinder liners.

And sometimes..... size matters.

[theSKSguy45]

And the barrel is on.

I used electrical tape on the back of a simulation round as a rough headspace check. I have proper gauges coming but it passed the initial test. If I was to hazard to guess I think the headspace is on the tighter end.

The barrel appears to be properly indexed

I needed to remove a little bit of material from the rear sight block to get it to fit but overall it worked fine


I apologize RM but a pipe wrench was used, I’d advise those with weak stomachs to look away now.






I elected to put the teeth in the locations where the rear sight block would hide them the best. I know it’s improper but it’s what I decided to do after a night to think about it.

I’ll have to re blue some spots and clean up the brass, copper, and aluminum that was implanted on the rifle from my sacrificial blocks, but honestly I’m happy with it so far. This is by far the most (and I hazard to use the term) “gunsmithing” I’ve ever done myself. Given this rifle was pretty solidly in the wall hanger category before I got it I figured it was the perfect rifle to test myself on. Worst case scenario it’s spares for my 1949. I guess I can now say I have a sino-Soviet SKS XD

All that’s left to do is shoot it from a vice and see if it blows up. Fingers crossed.

[echo1]

Best save job I've seen yet    PAX

[running-man]

GM is right on with his 'persuader' mentality.  Sometimes it takes heat, sometimes cold, sometimes a good penetrating oil overnight will do it, others are easy-peesy and there's no seeming rhyme or reason for it.

The barrel appears to be properly indexed

Very nice!  I'm glad that the indexing marks didn't lead you astray.  So I guess we can now safely assume that indexing marks are consistent between Soviet long lug production and early to mid Chinese long and short lug barrel (and receiver) production.

I apologize RM but a pipe wrench was used, I’d advise those with weak stomachs to look away now.

...

I’ll have to re blue some spots and clean up the brass, copper, and aluminum that was implanted on the rifle from my sacrificial blocks, but honestly I’m happy with it so far. This is by far the most (and I hazard to use the term) “gunsmithing” I’ve ever done myself. Given this rifle was pretty solidly in the wall hanger category before I got it I figured it was the perfect rifle to test myself on. Worst case scenario it’s spares for my 1949. I guess I can now say I have a sino-Soviet SKS XD

All that’s left to do is shoot it from a vice and see if it blows up. Fingers crossed.

Hey, when in need you use what you've got.  Nothing but admiration from me on this one! 

Now if you were a 'smith charging out at $150/hr for a custom build, then we could discuss...

Honestly though, great use of what you had, and I think it's going to turn out well.  Will probably be a great shooter too.  All the experience you learned in this one will go quite a long way on your next one (if there is one).  If nothing else, the photos and descriptions will help anyone else that comes after you wanting to do the same thing! 

[theSKSguy45]

My headspacing gauges finally came in and although on the tighter side the rifle passed with no problems

[echo1]

Nice. I have a MG go-no go for my shenanigans, PAX

[Phosphorus32]

My headspacing gauges finally came in and although on the tighter side the rifle passed with no problems

Great to hear! Fascinating experiment with the “cross-nation” indexing mark alignment. Glad it worked in the end