View Full Version : SKS rebuild
03-06-2009, 11:01 AM
O.K., we have a new project. Rebarreling a sks. Anybody have tecniques for bbl removal,installation? pressed/pinned chinese m21. Thanks.
03-08-2009, 08:52 AM
I have used an aluminum drift with a pilot turned on the nose to prevent the drift from slipping out of position (at a slight angle in an SKS chamber). Some penetrating oil and perhaps even heat my be needed prior to applying a 2 lb hammer.
The receiver was protected by shaped aluminum blocks lightly clamped in place. A large (6 inch or more) size vise restrained this assembly. Don't forget to remove the small barrel cross pin.
The Chinese SKS barrels are a nominal 19mm diameter at the breach like their AK barrels. I just measured one at 19.05mm.
A friend has successfully rebarreled SKS's to .223 cal after we had been told all sorts of horror stories and BS. I believe that the Chinese SKS receivers are castings. Others may be also.
Are you changing caliber on your SKS ??
03-08-2009, 03:58 PM
thanks, viper. No cal. change, chamber was welded inside,has lob of weld in chamber and bolt face was welded. Any idea why? I think it may have been a drill/parade rifle or something like that. Anyhow, my bud inherited it and has 0$ in it so we are going to try to get it running. I've rebarreled Ak's so I have an idea of how to go about it, but I wasnt sure with the rec. in the way. Taking the trunnion off an ak is easy since theres no rec. behind it to get in the way, but your way seems the way to go.
03-09-2009, 03:12 AM
Never re-barreled a SKS but I've thought about converting one to 223 for a long time, how did your friend do it viper ?? A New barrel, how did he close down the bolt face ? weld it up and re machine it?? What magazine did he use.. may be a tricky one. I think the best rout would be to get the SKS that takes AK mags and then get 223 ak mags one problem solved...as for rebarreling, I'd guess knock the cross pin out once it is removed, you press out the old barrel like a AK... I'd love to build a heavy barrel SKS like with a RPD barrel or bren barrel rechambered. I think that would be way cool... B2B
03-09-2009, 04:29 AM
Hello mtdew and b2b,
The welded chamber and torched bolt face are typical of Euro dewats that were once available over there.
SARCO or Numrich GPC may still have a Chinese 19mm SKS barrel or two left from the old days. An AK barrel is typically fatter and thus could be turned down as needed. If there is a pre-drilled gas port in the AK barrel you will need a work-around, maybe a modified SKS gas tube and piston. I recall that the SKS piston is 13mm diameter ie a bit smaller than the AK piston.
Very early Russian prototype AK's used the gas system borrowed from the SKS. However today the two gas systems are very different.
The .223 cal SKS variants used modified Stoner barrels. The stock SKS bolt was modified with a reground extractor that could hook onto the .223 rim to extract it. The same extractor would also push the case across the larger bolt face and into the SKS ejector. Tricky solution. No need to weld up and remachine the bolt face or ejector. However the fat SKS firing pin tip needs to be slimmed down to .223 size. The fat pin hole in the bolt tends to paper-punch the primers. Also a thin, tiny coin-like face was added to the SKS bolt having this smaller pin opening. Silver solder held it in place.
This over-size firing pin problem existed also on early Polytech .223 AK imports. The original 7.62x39mm firing pins are too fat for the higher pressure .223 ammo. They caused paper punched primers and blew crap back at you.
The SKS standard "magwell" was tweeked until it fed the .223 ammo efficiently. Grind a little here and there, bend tab "A" and tab"B" in slightly and carefully. Adapting a .223 AK mag is another solution. The SKS receiver must be opened up a bit much like when you adapt a regular AK mag to the SKS action. Also the bottom of the SKS bolt must be narrowed to pass between the AK mag feed lips.
Sorry I've forgotten the .223 cal gas orfice size. It's been almost 20 years ago. All in all the caliber conversion is not for the newbie.
03-09-2009, 06:00 PM
New problem-threaded bbl. Easy enough to get off and install, I've done numerous mausers, fal,galil,etc. Question is where to get threaded bbl for m21 sks? Thanks
03-09-2009, 06:33 PM
I'm not sure if these will help.
SKS Used Barrel & Barreled Receiver | e-GunParts.com (http://e-gunparts.com/DisplayAd.asp?chrProductSKU=501600&chrSuperSKU=&MC=)
SKS | TYPE 45, TYPE 56 | ITEM#878650 | e-GunParts.com (http://e-gunparts.com/product.asp?chrProductSKU=878650)
Here's Yugo barrel???
Yugo SKS 59/66 7.62 x 39 Barrel & Receiver Stub | e-GunParts.com (http://e-gunparts.com/DisplayAd.asp?chrProductSKU=855530&chrSuperSKU=&MC=)
03-09-2009, 07:02 PM
It may be worth a call to Numrich to ask if they have a used chinese threaded barrel. They aren't that rare and perhaps one of the cut up ones is that style. Other than that My Yugo is a threaded barrel also, but I don't know if the barrel threads are the same as the chinese.
03-09-2009, 07:58 PM
are the type 45,type56 threaded or pinned? I cant tell from the photos.
03-09-2009, 08:33 PM
I'm gonna call numrich tomorrow. The thing is that my boss bought the rifle from my friend because I had said it could be fixed for a hundred dollors. Hes all exited and now I'm not sure I can find a bbl. I sure wished I had looked at it closer and seen it was threaded not pinned. Now he has 60 bucks invested. Hes not just my boss but a good friend also so please help me find a bbl. Gunco folks are the best.Thanks
03-10-2009, 05:53 AM
I suspect that there are a couple different thread sizes used on SKS barrel breaches. One I had was a threaded european SKS (Yugo ??, Czech ??). It measured 25x1.5mm. Ironically the same as the Israeli FAL. So I screwed an Israeli FAL heavy barrel front end on the little SKS. It looked very cool !! Wouldn't work of course but it did look cool.
Talk with a knowledgeable person at Numrich GPC (e-gunparts). I have purchased SKS barrels and related bits from them as well as SARCO.
My humble guess is that the Chicom threaded barrel is about 19x1.5mm. If no such barrel can be found you will need a lathe that can turn 1.5mm pitch threads. Approximate gears will work OK. Timing and concurrent headspace will be a real bitch to catch. So be prepared to simply do the headspace and relocate the barrel fittings afterwards to the proper location.
There are threading dies in 1.5mm pitch that can work on metric gun barrels. These dies can be had cheap as they also re-thread trailer axles !! Very thoughtful of those trailer guys. A 16 TPI thread comes very close to 1.5mm pitch, like inch vs metric FAL barrels. You could make an aluminum test slug in 16 TPI to see how it fits the Chicom receiver.
An SKS "RPK" type sounds interesting. I like those early ZB and Bren barrel fins too. Break here while I go measure one...
The Bren barrel has plenty of meat and length to remachine for an SKS "RPK" type. The stock gas block would need an offset adapter... The breach is 23.24mm diameter minimum.
Omega Weapon Systems in Tuscon may still have some "Chinese" ZB-26 barrels in 7,62x39mm conversion. The breach end is 23.00 mm diameter minmum. Those do have fins too.
03-10-2009, 10:35 AM
wow,thanks for the info. lots of options now. centerfire has yugo barreled rec. 50 bucks,need yugo bolt. we shall see...
03-11-2009, 03:44 AM
Some used chicom SKS carbines have as much as 0.012 inch (twelve thou) headspace slop. That is extreme but not too rare. I prefer a snug fit of about 0.003 inch headspace based on the particular type ammo I expect to shoot in the gun. To get it that close you may need to mill or carefully file the bolt face edge back. The bolt face is rebated rather deep. An SKS can be rebuilt to shoot straight but quality ammo is also needed.
03-22-2009, 06:04 PM
Update- bought yugo barreled rec. from centerfire-Boss went to get it-atf denied him. Seems his crack head brother used his name once when he was incarcerated. Now boss has to get fingerprinted,etc.,etc. Hope it doesnt take long. Atf lady was real freindly,helpful.She says he really needs to repeal,all can be fixed. Not all atf bad I guess. Now playing waiting game. Boss is gonna tear brother a new one once he finds him.