View Full Version : My SKS build thread: strictly fundamentals

03-14-2015, 04:47 PM
Hey guys,

I'm relatively new to the forums here but I've been lurking for a while. With a couple of buddies of mine getting their PALs and taking up plinking and running and gunning on the weekends, I got sucked into it and I've been meaning to myself kitted out for a while. The papers I have, but these days, university and work aren't really conducive to getting out and shooting. Which is why I thought this would be a perfect time to be a cool kid and hop on the SKS bandwagon. Here it is out of the shop.

https://farm8.staticflickr.com/7622/16814399442_f82dfe7186.jpg (https://flic.kr/p/rBQc9E)[/url]

I thought I'd share my work, because I don't plan on going the typical routes, namely leaving everything stock and beating the living piss out of it or going all-out tacticool with tapco hardware. Rather, I'm trying to go OEM-plus with this, fixing the platforms inherent problems just to round off rifle. At the end of the day, what I want to build is an SKS that's a better plinker, and overall a better experience to shoot as it was originally intended: on a wood stock, with iron sights, and without a gazillion doodads hanging off of it.

This whole gunsmithing deal is all new to me too. While I think I'm pretty handy (women don't find me handsome, so I aught to be), this is something I've never done. I think it's a great project to get my tool collection started.

Here's what I plan on doing to the gun:

Bayonet & bayonet lug/front site delete
Furniture refinish
Front sight replacement
Improving receiver-stock interfacing
Chop, thread and recrown muzzle
Shaving down a few bits which I don't find useful

First step was disassembly and evaluating what needed to be done. I'm sparing you the photos because you all must have seen the process by now. Toughest part was getting the front sight and bayonet lug off the front end, consider I used an awl and not an actual punch. But hey, it worked!

https://farm8.staticflickr.com/7644/16195578143_83f9eb5601.jpg (https://flic.kr/p/rBQc9E)

Word on the street is this skinnier section where the front sight post used to be is already the right diameter for threading with M14x1 LF. My digital caliper is out of batteries, but but eyeballing it its seems to be close to the 0.552 inches diameter that specs say such a thread should have.

While taking the furniture off, I examined how the receiver beds on the stock and I discovered what is probably a huge obstacle to accuracy, on my example anyways. The way these things go together, the receiver holds the stock in a sandwich with the trigger group and magazine assembly. The problem with that is that if the stock is milled out incorrectly, the action can rock back and forth in the stock, like so:

[url=https://flic.kr/p/qEW8vY]https://farm8.staticflickr.com/7285/16193150614_7c658a7357.jpg (https://flic.kr/p/qF9z8V) (https://flic.kr/p/qEW8vY)
https://farm8.staticflickr.com/7646/16629377699_cb43fd38a2.jpg (https://flic.kr/p/rktUCB) (https://flic.kr/p/rktUCB)

First picture is with the back of the receiver completely mated to the rear of the stock, second is rocked to the opposite position. It's pretty clear that the bolt going through the stock transversely is acting as a pivot on which the receiver can rock. While it's theoretically being held in press fit with the lower components, however I think there is reason to believe that press fit shouldnt't be trusted.

To solve this I found two points where the receiver could be bolted down to the stock after the pivot point, torwards the rear. First one is back under the receiver cover fixing bolt.

https://farm9.staticflickr.com/8747/16195599453_9faaae4c02.jpg (https://flic.kr/p/qF9Ftk)

There is ample room for a medium sized metric bolt, something like a head-headed countersunk faster in something like M5 or M6, and ample room in the stock for a thread insert. This is probably where most of the gains in accuracy will be made, since it's the stock furthest away from the pivot point.

The second spot is to each side of the receiver, in the skinniest narrowest section of the bolt cut-out. On the picture below, the receiver would be drilled and tapped for something like M3 or M4 right about where the sideways C is, to the leftmost edge of it.

https://farm8.staticflickr.com/7602/16814400452_887b7435ac.jpg (https://flic.kr/p/rBQcs5) (https://flic.kr/p/rBQcs5)

There is a solid 6mm of solid steel on that point of the receiver, and enough wood to properly hold a countersunk screw. Those two basically just assist the first rear-most bolt in keeping the receiver as far back on the pivot as possible.

I've identified a possible anchoring point at the front, but that would involve filling the bayonet slit up with epoxy to get a threaded insert in there, then securing the front of the gun with a small screw going longitudinally through the metal cap that finishes off the stock at the fore-end. To make that worth it I'd probably have to bed in the front section of the receiver in first with bedding compound. I'll start with doing the first two and see from there.

For now, I've got an AK thread die and guide set in the mail and I still have to choose my muzzle device, so I'll working on stripping the furniture and working on the anchoring points.

Hopefully I'll update this with two weeks. Thanks for reading.

03-14-2015, 05:36 PM
http://i1328.photobucket.com/albums/w534/kennymo81/Mobile%20Uploads/54D097CC-CD55-4FBE-9F59-B8746E800CDC_zpscftx4tuw.png (http://s1328.photobucket.com/user/kennymo81/media/Mobile%20Uploads/54D097CC-CD55-4FBE-9F59-B8746E800CDC_zpscftx4tuw.png.html)

But I can't protest too loudly, one of mine rests in a folding stock with a Promag side mount..... I'll be interested to see what happens with the accuracy if you add those bolts through the stock.

03-15-2015, 01:06 AM
Where'd you find the AK die, and where can one locate compatible accessories?

Looking good.

03-15-2015, 09:44 AM
I found the die and guide on ebay, they ran me about 50$CAD for the kit. The die isn't anything special, just a reversed metric thread, the guide might be somewhat harder to find though.

As for accessories, I'm not too sure what you mean. AK threaded goodies are all over the places. If you happen to mean the die wrench and all that stuff, I already had a good set of taps and dies, so that I already have.

03-16-2015, 10:45 AM
As it turns out the Ares Armor Effin'a in AK variant (http://aresarmor.com/store/Item/AA-EFFINACAK) is on sale right now. Considering the great reviews and the fact that Ares does what they do for gun rights, it's all the persuasion I needed.

Once the brake is in I'll figure out where my chop needs to be and we'll get started on the real work.

03-17-2015, 04:33 PM
I'm interested to see how this turns out. Good luck!

03-21-2015, 03:18 PM
Did a bit more work on the gun this week.

For all intents and purposes, the furniture is now sanded and ready for tint and reseal. It's not on bare wood everywhere, but I feel that I'd be removing too much wood if I sanded it down further. The stain was probably just not correctly applied, and considering that I'll restain it in all black, having a patchy base color will probably not affect things much.

https://farm9.staticflickr.com/8734/16263471224_22fcb958c5.jpg (https://flic.kr/p/qM9xoh)

Did more measuring to make sure that everything I had planned can actually work. I can confirm that the barrel is reading within a few hundredths of a millimeter of the spec M14x1 major diameter on the slimmer section where the front post used to be. Spec is just slightly under 14mm for male threads, 13.974mm. This gives me more than enough room to chop and thread, with no need to turn the muzzle to an appropriate diameter.

https://farm8.staticflickr.com/7589/16699717449_82135316ee.jpg (https://flic.kr/p/rrGqbV)

Further stripped down the gun, removed the gas block and the front stock cap. The pins were surprisingly easy on those. As in one-shot easy. Either I'm getting good at these or the pins were original and / or slightly undersized.

https://farm8.staticflickr.com/7596/16859948186_f94dce1dc0.jpg (https://flic.kr/p/rFRDcQ)

The stock cap is going to get filled in so that I can redrill a hole for longitudinal bolt that will go through it. After seeing that the action still moves with the gun assembled, I'm definitely going to fill and bed the stock and anchor the front portion of the stock.

I also check out the CAD drawings of a couple of fasteners I planned on using for the anchor points, I'm gonna need to size down in order for stuff to fit. M5x0.8 for the rear anchor, M3x0.5 for the side anchors, all countersunk black nitride hex screws.

Here are the part numbers I'm going to order from Fastenal, probably gonna have to order a few more to actually place an order, if anybody else want to be a copycat I'll most likely have some leftover hardware.

M5x0.8mmx14mm - 40939
M5x0.8 hardwood threaded insert - 11138945
M3x0.5x10mm - 40923
M3x0.5x12mm - 40924

I've got the front sight figured out, I'll be welding the front sight post to the gas block. Apparently I'm not the only one to have thought of that (http://img.photobucket.com/albums/v357/grouster/SKS_0004.jpg). Gas block and front sight combos are off-the-shelf parts for AKs, but things are a bit tougher for the SKS. FYI, horizontal alignment should be 32mm from center of front sight circle to center of gas block mount. On the stock front sight, both diameters are exactly 14mm, and separated by 18mm. Words cannot express how happy I am of not having to work those numers out with fractions of inches.

https://farm9.staticflickr.com/8728/16885856665_fa1fce5a7d.jpg (https://flic.kr/p/rJ9qTK)

With the muzzle brake ordered, all I need now in terms of parts now is the following:
-Mason Reamers military recrowning kit.
-A set of steel Tech-Sights, so that I can have those welded onto the rear cover to get rid of the rear set screws and to minimize the amount of moving parts.

03-22-2015, 03:39 AM
Did you fire this particular rifle first before assessing any needs it may or may not require?

03-29-2015, 04:33 PM
its all neat, goodluck and i'd like to see pix when done of course :-)

03-30-2015, 09:08 PM
Did you fire this particular rifle first before assessing any needs it may or may not require?

I have not, because this particular rifle is nothing special. Keep in mind I bought this with the specific intent to tinker, if I happen to get a winning formula to making this platform more accurate, that's gonna be great. If not, I'm still going to have something that shoots lead downrage in a somewhat regular fashion, gunsmithing experience under my belt, and a slightly more rounded off set of tools. If t his were any sort of serious endeavor, of course I would have run a couple of baseline groups. But this is not what this is.

Tiny update on the Krink-style gas block. A bit of smoothing and we're in business.

https://farm9.staticflickr.com/8697/16825434730_ced8ec6133.jpg (https://flic.kr/p/rCNKyf)
EDIT: Fixed picture link

04-10-2015, 01:58 PM
So I was so distracted by the fact that I had bought a german-made die that I forgot to check what side thread it is; I bought a right had die. The only options for left hand dies were Chinese, so I have one of those en route.

Also my Fastenal order is now at well over a week, so no work on the gun for some time.

04-10-2015, 10:08 PM
Looking forward to seeing the results on this.

The SKS is a gateway gun, and I love to tinker. I haven't owned an SKS in years.

04-11-2015, 04:07 AM
Looking forward to seeing the results on this.

The SKS is a gateway gun, and I love to tinker. I haven't owned an SKS in years.

The gateway to more SKS's.....I have three and I find myself wondering if that's enough....

senior cheeks
04-12-2015, 11:34 AM
The gateway to more SKS's.....I have three and I find myself wondering if that's enough....

I thought 3 or 4 was enough ,but I was wrong.I find I now have 7 and that`s getting close to enough ,but I like a nice round number ,so 8 seems reasonable LOL

OH....3 of those are Chinese, the rest Russian.

To the OP ,very nice thread and project ,like it !!

As mentioned, the SKS is indeed a great gateway gun ,as I myself turned one into a Dragunov and another into an AK version.Both turned out nicely and were fun projects.

Keep it coming !


05-01-2015, 12:13 PM
So I was so distracted by the fact that I had bought a german-made die that I forgot to check what side thread it is; I bought a right had die. The only options for left hand dies were Chinese, so I have one of those en route.

Also my Fastenal order is now at well over a week, so no work on the gun for some time.

If they are RH x 14 the CZ858 brakes will work on that.

05-01-2015, 12:16 PM
We have a front sight kit just for people who want to remove the bayo lug assembly.

Here is the front sight with AK threads built in, It is same plane as the factory sights, so you can mix & match. It will allow you to remove the front sight /Bayo lug assembly. It also uses any AK muzzle brake, & we have a LOT of different brakes in stock, HERE! (http://www.hical.ca/search.php?search_query=brake&x=0&y=0)

http://i629.photobucket.com/albums/uu12/mp5k1/trueshot%20sight_zpshd8m1a6e.jpg (http://s629.photobucket.com/user/mp5k1/media/trueshot%20sight_zpshd8m1a6e.jpg.html)

05-03-2015, 07:41 PM
Thanks for the offer, but it's a bit too late for that.

Got the brake last week:

https://farm8.staticflickr.com/7673/17175453739_b0d9e7852f.jpg (https://flic.kr/p/saJG1K)

LH die is due any time now. Found the resin I was looking for, I'll start filling in the stock this week, maybe attempt bedding some time next weekend.

Now all I need is a set of solid carbide countersinks, that's probably gonna run me the price of the gun :S.

11-28-2015, 07:41 PM
Believe it or not, the gun has been in parts all this time. Life got in the way of messing around with this stuff. I tried tapping the barrel without cutting it off as a test, the threads looked great but they were very crooked. Chopped off half an inch, threaded, still crooked. At this point, I got tired of trying and chucked it in the safe.

Months, later, got tired of the bare action laying around in my safe, so I brought it to a first machine shop back in late August. After well over a month of telling me they were gonna look into it, I took it back. While getting a job done for wheels on my truck, I asked another machine shop, they were down to do it and they had proved to be much more efficient at getting stuff done. I had the crooked thread chopped off, the muzzle recrowned and threads dones on a lath. They are perfectly aligned now. To be honest, save yourself the money and go straight to a machine shop if you want this done to yours. If you value your time at anything over minimum wage, it's totally worth the 80$ or so I paid to get it done right the first time. As a bonus, I didn't have to buy a recrowning tool.

The barrel is now at approximately 18.75" without the brake, or well within the limits of the law. I remounted my Krinkov-style front sight and the stock cap on the barrel, and mocked up the gun in assembled for. It looks like this:

https://farm1.staticflickr.com/659/23356585606_bd68391fbe_k.jpg (https://flic.kr/p/BzWBaQ)

Closeup on the assembled front sight:

https://farm1.staticflickr.com/686/23014779929_091a8e2318_k.jpg (https://flic.kr/p/B4JLfv)

I've tried assembling the anchors in the stock, and it's not going as planned. After breaking 3 expensive drill bits in the receiver for the side holes, I gave up. The rear I was able to drill through and countersink properly (it took hours), but the insert doesn't have enough wood around it to work correctly. I'll probably fill the rear hole with fiberglass resin and tap directly into that, and forget the side mounting points altogether.

I've also started glassing-in the bayonnet and cleaning rod channels in the stock, but I've been doing that at work, so no pictures of that. If I can get my hands on proper release agent, I might tried to bed the back end of the barreled action just to practice bedding with regular fiberglass resin; I have a few of my bolt guns I'd like to bed properly.

Techsights will probably be on order during the Christmas break, giving me time to work on the stock and refinish it. Sight radius is about 3-4 inches better than with the regular sights, according to my calculations. With the stock rear sight, it's 9 inches. :Bang head:

If all goes well I might be shooting this thing before the third quarter of 2016. :tounge:

Now that I know where and how to get proper chop and thread jobs done, I really want to do a shorty SKS with a threaded and welded-on AK style brake at a flush 18.5 and some sort of micro-red dot mounted on the front portion of the receiver or something. But I'll hold off until this one is finished.

11-28-2015, 08:05 PM
That homemade gas block sight really changes the look of things. Interesting stuff.

11-28-2015, 10:22 PM
Interesting build.

12-11-2015, 09:38 PM
Very cool. I like that gas block sight.

If you ever decide to sell the rifle PM me.

01-06-2016, 09:26 PM
Very cool. I like that gas block sight.

If you ever decide to sell the rifle PM me.

Thanks for the offer, but seeing that I'm well over twice the value of the gun in tools and accessories, I think I'll be keeping this one. If you have around 800$ laying around and want to thow it at an SKS, I'd be happy to build you a clone! :P

I didn't give you guys a preview of what the gun looks like fully assembled last time, so to start off, here it is.

https://farm2.staticflickr.com/1486/23926235780_6481bf5650_z.jpg (https://flic.kr/p/Cshdjy)

Doesn't it look the part? Not having that dinky bayo lug on there sure helps in the looks department.

In the spirit of the build, I want to remove anything that won't be of use on this gun, and since the rear sight blade is gone and not likely to come back, I figured I'd shave that bit. And so, this everything that's back of the tape had to go.

https://farm2.staticflickr.com/1708/24221789425_4157e1da7e_z.jpg (https://flic.kr/p/CUp184)

The result is a nice, flat-ish surface I can weld some bar-stock onto to plug the hole where the piston return spring is apparent. On my next build, I'll probably have this done by my machinist to make sure that the resulting cut is exactly straight and perfectly in line with the bore. This is how much space this gives me on there. I'm sure some of you can piece up (http://holosun.ca/index.php/products/hs403a) where I'm going with this (http://www.gunsnorthwest.com/18-steel-picatinny-rail-18-rail.htm). My plan is going to involve reworking the gas block detent, but I think I've got that all covered.

https://farm2.staticflickr.com/1446/24113727262_5c1312bee8_z.jpg (https://flic.kr/p/CJRa1j)

Resulting sight picture is much better, with the top handguard now being the interference in my sights, not the gas block detent.

[img]https://farm2.staticflickr.com/1690/24195763776_3c8d8c5b0e_z.jpg (https://flic.kr/p/CS6BAY)

Tech-Sights hooked me up with a set of customer-returned steel TS100s which are a perfect candidate for all the welding shenanigans I'm going to be doing. I had to provide a US shipping address, but they were incredibly helpful in getting me what I wanted and saving me a couple of bucks in the process. Now getting the parts home might actually take a while... but if you're still following this thread at this point, you're probably not surprised.

I also splurged on a steel threaded NC-Star AK-style brake for my next build, it was under 20$ on Amazon and I was not gonna let the US dollar get worst on me. Still looking out for a barrelled action for that too. Still haven't found release agent at a decent price, I might be holding off bedding the stock and just re-finish it while I'm without a rear sight anyways. I'm also really tempted to shoot it with just the front sight just to get the muzzle device set with lock-tite and everything.

As always, updates will be posted whenever they come.

01-06-2016, 09:57 PM
This is turning out great!

01-07-2016, 04:05 PM
Thanks for the offer, but seeing that I'm well over twice the value of the gun in tools and accessories, I think I'll be keeping this one. If you have around 800$ laying around and want to thow it at an SKS, I'd be happy to build you a clone! :P

I didn't give you guys a preview of what the gun looks like fully assembled last time, so to start off, here it is.

https://farm2.staticflickr.com/1486/23926235780_6481bf5650_z.jpg (https://flic.kr/p/Cshdjy)

Look'n more and more like a M59/66 from a distance.

01-14-2016, 10:18 PM
Got the brake for my next build, thought I'd share a preview:

https://farm2.staticflickr.com/1537/24387103685_6e458dd15c_z.jpg (https://flic.kr/p/Da1hhV)

Just from the weight of that AK74 brake, I'd say that even if it did nothing with diverting gases, you'd still get a reduction in muzzle rise from hanging on the end of your gun. 5 ounces of steel... it's a big MFer.

Photo shows the Ares brake in it's original position, and the AK brake more or less where it will be once it's welded on the new project.

04-03-2016, 05:45 PM
Thats why i love GOC. Nothing but support here whereas if you were on CGN youd be getting abused left right amd center. Keep it up!!

04-17-2016, 02:32 PM
Almost 13 months later, I got to shoot the damn thing. I helped a buddy with a proper gassed mig move a compressor, so I got to use his welder to do work on my receiver cover.

I wish I had more pictures of how I chopped the Techsight, the only one I could find is this one. Taken on top of tax forms... :confused1:

https://farm2.staticflickr.com/1513/26488662645_597c1fd95e_z.jpg (https://flic.kr/p/GmHjy6)

I went to a local welder initially, who wouldn't do it without a jig, citing risk of weld creep, expansion, yadda yadda yadda. Found this way to keep things together, and it worked together great, despite that I had a lot of grinding to do afterwards. Result:

https://farm2.staticflickr.com/1569/25885480403_d98a78f12d_z.jpg (https://flic.kr/p/FrpRug)

Not the prettiest, but I'm not gonna win a beauty contest with a discounted b-grade SKS anyways. Still looks better than any tacticooled out tapco-stocked piece of shit if you ask me.

https://farm2.staticflickr.com/1575/26396158442_5d125e22bf_z.jpg (https://flic.kr/p/Gdxdh3)

Performance at the range was very good. For one, target acquisition is MUCH faster than with blade sights. After a bit of struggling with sighting at 50 because I was using the 200+ aperture, I moved it out to 100 yards and got this group. 10-rounds ghetto supported sitting, Norinco copper-clad corro surplus, after more or less 50 rounds in half an hour.

https://farm2.staticflickr.com/1512/25883420774_dd1a25ae9d_z.jpg (https://flic.kr/p/Freieq)

Let's call that 4.5 MOA. I must admit I had a bit of trouble sighting in because the orange target was barely visible at 100 yards, but that's all I had time for: lots of people at the range today. Obviously needs further adjustment, but both front and rear sights are almost perfectly centered, which means I haven't completely fucked up on the welding. Still, pretty decent. I'm gonna make the front sight pointy, that'll be a start. I'd also really like to get a battle rifle crowning tool kit from Manson Reamers (https://mansonreamers.files.wordpress.com/2015/06/january-2016-catalog-cover-ii-small-file.pdf), but it's kinda expensive if I'm not gonna rent it out or or use on any other gun. If any of you guys want to get in on some of that action, please let me know.

I don't think it's unreasonable to say that this is probably a 2 MOA capable rifle with surplus ammo with everything sorted out. Not to mention it's much more shootable. I didn't get to adjust the brake because standing was a no-go at the rifle range and only rimfire was allowed on the pistol range. Soon though.

The buddy with the welder has a sandblast, gonna go with a BBQ paint refinish unless somebody volunteers something more exotic... not pumping more money in this thing just yet.

Still looking for a bare action to get my next build started. Stayed tune for the results of that one in 4 years time :P.