An SKS Story

[pdowg881]

So today after shooting my SKS I started to break it down to clean it. After getting out the bolt assembly I accidentaly dropped the bolt. It landed so that the back of the firing pin where the hemmer hits hit direcly on the side of the stock. Left a mark like a had hit the stock with a punch. Made me angry because I had just refinished the stock, but no big deal. The fact that the mark looked funny caused me to examine the bolt, which is how I discovered the mark was from the firing pin.

Thank god i did, because The firing pin was jammed forward. (Slam Fire anyone?) I tried to pull on the back of the firing pin and using the tool in the stock for cleaning the gas valve that looks like a punch to try and push the firing pin out from the front. I even tried vice grips, but due to the cone shape of the pin I couldn't get a good grip.
So down to the workshop.

I got the firing pin to the rear position by sticking the back of the pin in the vice and pulling the bolt back. I then checked to see if the pin moved freely. It was a little gritty and stuck a little in the forward position. So I noticed when dissasembling the bolt that the small raised part that stops the pin from sliding out the back of the bolt when the pin stop is in had a dent in it. I smoothed it out. But the pin still stuck a little. I wasn't going to take any chances with it like this.

Upon more examination I found the real problem. Since the front of the firing pin, and the inside of the bolt where the bolt rests are both cone shaped, the face of the bolt where the pin protudes had a burr on it from being hit so hard when i dropped it. Having the conical shape of the pin and inside of the bolt is a perfect way to cause them to bind. In my opinion, a poor design. So I found a drill bit the same size as the pin hole in the bolt face and slowly drilled in it to get off the burr so that the hole was nice and round again. I then used very fine sand paper to smooth out and polish up the conical part of the front of the firing pin to prevent any further problems. I also did some more fine smoothing and sanding in other areas to be certain. After a lot of dry firing it's working fine, pin at the rear when the bolt is racked (hopefully it stays that way when the bolt comes forward). The only way to be sure now is to test fire it. And you can bet I'll be loading single rounds for awhile.

So I went from a quick bore and bolt assembly cleaning to a frustrating time in the wrokshop. Lessons learned: Always examine your sks and it's firing pin each time before shooting to prevent slamfires, the design of the firing pin in the SKS could be much better (which I've read initially was before cost cotting design changes), and lastly, that looking into aftermarket parts that old the firing pin to the rear under spring pressure may be something to look into as an improvement over the free floating design.

You can also bet every time I see that ding in the stock I'll remember the whole mess.

Here's a good explanation about the original bolt design vs the one that was actually used: http://www.murraysguns.com/sksown.htm

 

[bill larry]

You can always try a spring loaded firing pin kit from Murray's if you're worried about slamfires.

 

[pdowg881]

Too bad it wasn't part of the design when it went into production though.

 

[Limeyfellow]

Originally when the SKS came out the Russians did put in a spring like that, but they removed it from the design when it wasn't deemed needed, especially with the hard primers used by Soviet military rounds.

Of course the Garand and many other military semi automatic rifles has the same problem. A free floating firing pin.

Shame you had such a buggered firing pin.

 

[dstorm1911]

its also a very good demonstration of why ya never dry fire an SKS or an AK although an AK will take a lil more dry fireing ie; empty mag click excessive dry fireing will have the same effect ya experienced with your SKS, if ya wanna prevent it from happening so easily in the future get a 3/16" ball diamong burr for your dremel with the 3/32" shaft rather than the 1/8" shaft drop it into the fireing pin hole shaft first so the shaft comes out the Fireing pin hole then chuck it in your dremel tightly and at a low speed pull the ball towards ya lightly ya will add a chamfer to the inside of the FP hole that will prevent the pin from causing the burr ya will need to measure pin protrusion before and after then after your done file the tip of the pin to get it back to its original protrusion...... it will take many dry fires to get it to burr after the mod