Gunsmithing SKS slam fires?

howdydoit

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My father is giving me an SKS so not sure which country it came from if it even matters.

But he says it will slam fire every once in a while. I didnt ask if he loads a round in the chamber first with empty mag, or if it strips a round and fires. So not sure there.

What would cause it and how can it be fixed?
 

mavrick10_2000

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Re: SKS slam fires?

Floating firing pin with loose tolerances cause this issue. There's someone out there that makes a spring captured firing pin for the SKS to prevent this. Can't remember their name at the moment.
 

300WSM

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Re: SKS slam fires?

soft primers can cause this on these types of guns. Sticking with mil spec ammo should help.
 

Greg Langelius *

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Re: SKS slam fires?

A dirty firing pin recess could be the cause as well. Give that bolt a good soaking in solvent and if possible blow it out with something that will clear out the interior.

If it's happening on the first round, it's likely the result of human error. If it's happening on rounds that have been fed from the mag, it's more likely to be a mechanical issue.

Personally, I've gotten so accustomed to single feeding all semis from the mag that I tend to cringe when I see someone put a round into the chamber by hand and turn that bolt loose. The bolt drag imposed by the magazine feeding process is a key design factor in semiauto operational procedure for safe operation. I can remember being smacked in the back of head (Gibbs style) in PI for doing it wrong with my M14.

Greg
 

mikNtx

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Re: SKS slam fires?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: mavrick10_2000</div><div class="ubbcode-body">Floating firing pin with loose tolerances cause this issue. <span style="color: #FF0000"> There's someone out there that makes a spring captured firing pin for the SKS to prevent this.</span> Can't remember their name at the moment. </div></div>


http://www.murraysguns.com/sksown.htm

eta: i agree w/ the mentioned above about stripping the bolt and cleaning the firing pin. its not hard to do. a lot of sks' were stored in cosmoline and need a thorough cleaning.

also please check out:

http://www.sksboards.com/

http://www.yooperj.com/

and a manual

http://www.sksboards.com/sksinfo/sksmanual.html
 

howdydoit

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Re: SKS slam fires?

Thank you all for the info, when I get my hands on it ill check it out and post back.

thanks agian
Howdy,
 

pepperbelly

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Re: SKS slam fires?

I collect C&R rifles, and this is a common problem with a simple solution.
Most people just spray the bolt and blow it out. This is not good enough to clean it. There are many online tutorials on how to disassemble the rifle and the bolt. Take the bolt apart and clean it. I ahve had several friends who bolied their bolt to remove the cosmoline and were very surprised when they took it apart at how much was left in there.
The slamfire is usually caused by the cosmoline and added crudholding the floating firing pin forward. When the bolt closes the round fires.
Be aware that this is not full-auto fire even if it sounds like it. When an automatic rifle fires the disconnector still works- it delays the hammer/firing pin strike until the bolt is closed. During a slamfire the bolt is not fully closed. This makes it very risky- case head seperations and debris being blown into your face.
This is a condition that really needs to be addressed before you fire the rifle. If it has occurred before like you said it will only get worse.
Take the bolt apart and clean it.

Jim
 

Clark

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Re: SKS slam fires?

Some guy filed down on the sear in his Garand, and the the thing doubled and the old Weaver scope came back and gave me the cookie cutter eye brow. I had a scar for a year.

I think that it is easy to mess with a bolt action trigger and get it down to 1.5 pounds.

But a semi auto with disconnector, 4 pounds is about as low as home made should go.

What does it all mean?
SKSs are famous for doubling when the firing pin bore is full of hard grease, but there is another way to make it happen.
 

pepperbelly

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Re: SKS slam fires?

You are correct- there are other ways to cause it to double or worse.
I also have a Garand. Once during a match I was shooting prone. I didn't have the sling adjusted right and had a double. It was from what is called bump fire. The rebound from the recoil pushed the trigger against my finger.
With an SKS, unless it has been altered, the most likely cause is a dirty bolt.

Jim
 

gun-rx

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Re: SKS slam fires?

I've got a scar in the palm of my right hand from 13 stitches and a Garand slam fire that happened some years back. The cause was a floating firing pin and soft primer cups. About a year after this happened, Federal thickened their primer cups. I personally saw the slam fire effects 3 times that same year. After my incident, I installed a rebound spring on the tail of the firing pin.
 

Greg Langelius *

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Re: SKS slam fires?

A Garand's trigger group design lends itself to doubles.

There is a very small zone along the trigger manipulation path that releases the hammer, yet cannot recapture it.

When the trigger is manipulated too slowly and gently, the hammer hooks miss engagement and the hammer rides the bolt forward and ignites the primer as soon as the firing pin extension clears the safety notch in the receiver. This is not a slamfire, as the ignition cannot occur without the bolt lugs being at least moderately engaged.

There is nothing wrong with such a rifle, it is simply being manipulated incorrectly. The Garand trigger was not designed to be manipulated by BR shooters. It was designed to manipulated by infantrymen.

The proper manipulation method employs a relatively firm, smooth, and moderately swift pull that clears the disengagement zone quickly enough to reestablish hammer capture capability before the hammer cycles to the point where it is required.

A slamfire is an entirely different animal.

Greg