Caution with SKS carbines

SKS Ray

Moderator
NES Member
Joined
Jan 14, 2006
Messages
16,728
Likes
1,626
Location
South Eastern, MA
Feedback: 56 / 0 / 0
Military surplus shooters and fans of modern commercial firearms are now more than ever taking note of Sergei Gavrilovich Simonov's invention that first came out in 1945. With the recent flood of Yugoslavian SKS carbines in the United States more and more shooters are finding out what fun these little semi auto rifles really are. Yugo SKS models like the 59/66 are affordable on almost any shooter's budget and are a 7.62x39 alternative to the sometimes expensive AK47. Problem is the SKS rifle has gotten somewhat of a bad reputation because of its ability to go uncontrollable full auto. This is an error that can be avoided if the shooter takes the proper safety steps.

First off since the SKS is a military rifle it was meant to fire military spec ammunition. Many shooters make the mistake of buying a box of commercial hunting 7.62x39 ammo and fire it through their SKS' and AK47s. Commercial ammo unlike military spec ammo is made with soft primers and is usually meant to be used in bolt action rifles. Because the semi auto SKS' firing pin rides against the primer when a round is chambered from the magazine, there is danger of igniting that primer before the trigger is pulled and the firing pin is released. I myself am guilty of this because a while back when I got my first SKS I didn't know any better. I was using Federal 7.62x39 ammo in a Chinese SKS that had been properly cleaned and after shooting a few rounds I had 3 go off full auto on me. Luckily nothing happened to me or the rifle but it scared the hell out of me because I never expected it. A veteran shooter a few lanes away came over and explained what had happened and I've never used commercial ammo in any semi auto since.

The other common cause of an SKS going full auto is a dirty rifle, especially the bolt. I've seen so many surplus rifles both for sale and at the range that people have just wiped down and never properly cleaned or inspected them. What people fail to realize is that years ago when these rifles were packed up and put away for future use, they were disassembled and packed with cosmolene to prevent rust and keep them preserved for long term storage. Its not uncommon to see posts from new milsurp shooters saying their rifle doesn't fire a round sometimes even though the primer is dented. The first reply is usually "Did you check the inside of the bolt for gummed up cosmolene?" SKS rifle bolts are often packed with cosmolene which sometimes keeps the firing pin from moving freely and allowing less pressure on the bullet's primer when the bolt is chambering a round. The result... often a slam fire sometimes followed up by uncontrollable full auto fire. I know to some this sounds cool but think of it this way. If the bullet is not properly seated in the chamber when that round goes off, excess gas pressure builds inside there sometimes resulting in shrapnel from the ruptured casing exiting the receiver, or worse yet the receiver itself actually being torn apart. Think of a small bomb going off a few inches from your face. Not my idea of a fun day of shooting.

The SKS rifle bolt is a simple design and easy to work on but it needs to be completely clean in order for it to function the way it was meant to. I'm not going to show pictures with circles and arrows here but am going to post a link to surplusrifle.com's section on disassembling the SKS bolt.

http://www.surplusrifle.com/sks/boltdisassemble/hs.asp

www.surplusrifle.com is a great reference for disassembling and cleaning military firearms. I can't thank Jamie Mangrum (site's owner) enough for the valuable info he's offered to milsurp shooter's over the years. Following the procedures he shows will guide you step by step in disassembling and reassembling your SKS bolt. First off I'd like to suggest reading all the steps a few times before attempting them. That will help familiarize you with the bolt and its workings before you start taking it apart. I'd also like to point out some things that I've noticed from working on SKS bolts that will make understanding the procedures shown a little easier. Print these out if you want and keep handy when following the info on the site.

First thing is that when you are tapping the retaining pin out, observe how it comes out of the bolt. The best thing I've found to use is a large piece of wood like a chunk of 2x4 with a hole drilled in the center that's large enough for the retaining pin to fall into when its tapped out. Also, use a punch that's slightly smaller in diameter than the retaining pin. If your SKS came with a kit, the punch in there will work. Sometimes these pins can be stubborn so a few drops of penetrating oil is recommended to help drive them out.

Secondly... when the retaining pin is out, observe how the firing pin comes out of the bolt! You'll need to put it back in the same way in order for it to function and for the retaining pin to line up. The firing pin is triangular shaped and has a small raised area that blocks it from falling out. You'll notice this when you first take it out.

Now, after you remove the extractor as shown in step 4, its time to clean the bolt. There are several products you can use to get your bolt squeaky clean. 3 things I suggest though are Q Tips, pin point nozzles to spray inside small areas, and compressed air to dry the areas out and blast away dirt and crud. A can of compressed air such as the type used to clean PC keyboards will work if you don't have access to a compressor.

The 3 main areas you need to clean are
1) the hole the retaining pin fits into
2) the slot the extractor fits into
3) and most importantly where the firing pin goes!

Any left over grease or dirt could cause your bolt to not operate smoothly. Items such as pipe cleaners, Q Tips, small round brushes, etc. can all be used to scrub away and get these areas clean. I usually pull a small amount of cotton off the ends of Q Tip so it will fit and push it through the firing pin hole. You won't be able to get it all the way through but can grab it from inside the notched out area of the bolt with needle nose pliers and continue to push it through and finally pull it out. Spraying the bolt inside and out with products like Break Free, Gun Scrubber, etc. will dissolve any grease and cosmolene inside and out. Blowing compressed air inside and out of the bolt will allow you to get it completely dry before reassembly.

Another thing I'd like to mention is that the tiny extractor spring that keeps pressure on it to lock it in place should also be removed. This is done by pulling on it until it snaps out. You'll find lots of grease in there which can heat up and seep back out onto the bolt when it heats up during operation. Once clean you can insert it back in and install as directed in the diagrams.

One more note is when you put the firing pin back in as shown in figure 7, make sure you remember how it came out and its as shown in the diagram. When you look through the hole where the retaining pin goes with the firing pin inside the bolt, you'll see where the flat side of the firing pin along with the raised area allows for the retaining pin to hold the firing pin in place. The retaining pin has a U shaped face that shows where it should be seated in the bolt once tapped back into the hole. Make sure its lined up as even as possible when tapping it back in to avoid binding the firing pin.

Once fully assembled you should be able to shake the bolt fairly hard back and forth and have the firing pin move freely and even rattle a little inside the bolt. Push the firing pin in and out with your fingers to make sure there is no resistance. If the firing pin is tight and doesn't move in and out, disassemble and retrace your steps to find out what you did wrong.

Once the bolt is together and everything functions as it should, at this point you may be tempted to spray it down with oil before putting it back in the rifle. DO NOT OIL THE BOLT! Wipe it dry and leave it as is. If you're worried about corrosion due to humidity, whatever, at the most use a silcione cloth and barely wipe it down. Oil (especially poor quality) can gum up inside the hole and cause the firing pin to stick bringing you back to square one.

And that's basically it when making your SKS safe to shoot. Of course thoroughly cleaning the rifle's chamber, gas piston, etc. and getting rid of overall cosmolene is also in order. You can follow the steps found on surplusrifle.com's site and learn how the complete rifle comes apart too. http://www.surplusrifle.com/sks/carbine/index.asp

Using military surplus ammo and ammo designed to military specifications in a properly cleaned and inspected SKS should never pose a hazard to a safe shooter. I'm posting this info to be made a sticky so others can enjoy shooting these rifles in a more safe manner. I'd like to point out though that I am not a licensed gunsmith, just a milsurp collector/shooter that enjoys watching this part of our sport grow and enjoys seeing others get into it. Take the info mentioned here as free advice and in no way am I or anyone here at NES to be blamed for negligence or any mishap that may occur while shooting an SKS carbine. Safety is up to YOU the shooter and if you don't feel comfortable performing the proper cleaning, don't bring them to me, have a licensed gunsmith do it for you.
 
I have found that soaking an assembled bolt in a can of gasoline overnight works very well in removing cosmo from the bolts.

As always use extreme caution when dealing with gasoline or other solvents. Do not use indoors, let the bolt soak outside in a sealed container.
 
I would suggest ANOTHER solvent (Kerosene) instead of gasoline!

Gasoline is too dangerous to work with and remember that the fumes can easily ignite.
 
I would suggest ANOTHER solvent (Kerosene) instead of gasoline!

Gasoline is too dangerous to work with and remember that the fumes can easily ignite.

Non-chlorinated brake cleaner works really well, I've also read that WD-40 works good for removing cosmoline.

I'd still detail strip the bolt (rather than soak it assembled). At first, I cleaned it
fully assembled (using the brake cleaner). Then I started finding out more about the safety issues. I went back, stripped the bolt and sure enough there was still huge amounts of cosmoline inside.
 
I've also read that WD-40 works good for removing cosmoline.

That's what I used. Melted the stuff right off.


I am going to check mine out this weekend.

I have a problem with my bolt not returning all the way forward.
 
Sitck all the rifle parts in a galvanized trash can and place it next to a wood stove. The heat works awesome for softening up the cosmoline. Some scrubbing will be involved, but most of it should be able to be wiped off with a rag.
 
I was fortunate in that my Russian SKS came to me from someone who takes great care of his weapons. It was clean as a whistle. Still, this makes for very informative reading.

I've found the Simple Green works great for getting Cosmoline off of guns. I used it for both of my SMLEs which came completely covered. The key is to dry the parts thoroughly and use plenty of Break Free or other quality lubricant.
 
There is no way to just soak an assembled sks bolt and have it come out clean. The cosmoline is trapped inside the bolt. While the firing pin may feel free right now it can stick and go full auto at anytime. The bolt must be disasembled completely and cleaned properly to get the cosmoline crud out.

I shoot only ammo manufactured for my sks and when i reload for any military semi auto i use the #34 CCI nato primers there thicker walled primers so floating firing pins in military semi auto's won't be a problem. There are CCI nato primers available for the .223 caliber too besides the larger bores.(CCI #34)

The worst cosmoline i have cleaned was the Albanian sks's and i used kerosene in a large blue tub from walmart and let them soak and every few days with a soft parts cleaning brush scrubbed them until they were clean. Then i used the G.I. Rifle bore cleaner over all the parts and disassembled the bolts and gave it a G.I. cleaning. Then I assembled the firing pin into the bolt with a very thin coat of oil then wiped it off so it can't rust. I lubed the receiver, bolt, bolt carrier, gas piston and tube with a light coat of moly and she is good to go.
 
There is no way to just soak an assembled sks bolt and have it come out clean. The cosmoline is trapped inside the bolt. While the firing pin may feel free right now it can stick and go full auto at anytime. The bolt must be disasembled completely and cleaned properly to get the cosmoline crud out.

If you soak it in gasoline, it WILL dissolve the cosmo and get it cleaned as well as if you dismantle it. Some solvents will not dissolve cosmo completely but gas makes it disappear. I've done this several times.

I have been using gasoline to clean car and gun parts for over 45 years, as have many people I know who restore antique cars. It must be used outdoors and away from any source of sparks or flame.

Used properly, it can be used safely.....just like guns.
 
Milsurps,
Good post, well written and a valuable reminder.
The warning applies to most former military semi auto rifles.
The French M49s are well known for slam fires with soft primers.
Please be aware, also, that during the time that the Chinese SKSs were flooding the market, many were made with improperly heat treated parts in the trigger group. They can go full auto at any time as the parts tend to wear out quickly. I would recommend starting with 1 or 2 rounds in the mag when firing any unknown Chinese SKS for the first time and consider replacing any suspect trigger group with a new one before problems develop.
 
My suggestion is to disassemble the bolt, soak in Stoddard Solvent or Kerosene, scrub and reassemble. Gunk and Kerosene would also work. Spray Carburetor Cleaner or Brake Cleaner would work as well.

Sorry, Pilgrim, but Gasoline is just too dangerous to use. You only make one mistake with it, you'll refrain from using it again, if you make that mistake. Nasty stuff.
 
I've used carburetor cleaner many times, be sure to wear safety glasses in case of splash back from the pressure. I still tear the bolt assy down all the way occasionally.
 
I tried soaking the bolt at first and later took it apart and found the cosmoline still in the bore and on the firing pin. Your not getting it all out when soaking the assembly. Then i burnish some moly on the firing pin and wipe off the excess and assembly it dry just with moly in the pores.

The slam fires were mainly caused by not cleaning the bolt and the american made ammo at first had soft primers. I use CCI#34 primers in all my military guns wether its bolt action or semi auto so the ammo doesn't get mixed up when loading two different primers I just stick with the nato primers for all my military calibers. They also offer the small nato primers for the 223 too. Besafe do it right.....we need you here..and your family needs you too.

Becareful using carb cleaner around open flames like pilot lights I have seen the vapors go up. Use it with care and in the open areas too.
 
Last edited:
Back
Top Bottom