SKS Slamfires


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rugerman07
February 14, 2009, 06:58 PM
How prone are SKS carbines to slamfiring (full auto)? I got this info from Wikipedia:

"While early Russian models had spring-loaded firing pins, most variants of the SKS have a free floating firing pin within the bolt. Because of this design, care must be taken during cleaning (especially after long storage) to ensure that the firing pin does not stick in the forward position within the bolt. SKS firing pins that are stuck in the forward position have been known to cause accidental "slamfires" (uncontrolled automatic fire that empties the magazine, starting when the bolt is released). This behavior is less likely with the hard primer military-spec ammo for which the SKS was designed, but as with any rifle the user should properly maintain their firearm. For collectors, slamfires are more likely when the bolt still has remnants of cosmoline embedded in it. The firing pin is triangular in cross section, and slamfires can also result if the firing pin is inserted upside down."

Is this a common problem with the SKS? Should you only shoot Military Surplus ammo in it? Wolf & Silver Bear ammo have hard primers, could using them cause an accidental slamfire?

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my762buzz
February 14, 2009, 07:18 PM
Wolf, Bear,Golden tiger, and many other foreign 7.62x39 ammo
brands are made with hard primers for this reason. Hard primers prevent accidental slamfires. I'm not totally sure
Federal , Winchester, Remington, or other domestic ammo has
hard primers. Other than the ammo having softer primers,
a cosmo lined firing pin channel that wasn't cleaned out properly
can potentially cause the firing pin to remain stuck in the
forward position. Another way to cause a slamfire is reinserting
a firing pin upside down after the bolt was disassembled and cleaned.


If your really worried, you can always do an easy solution.
http://www.murraysguns.com/sksown.htm
“Original” Russian style, newly manufactured, CNC machined and heat-treated 420 SS firing pin and “Wolff” spring are now available. Drop in fit with no alterations required. Fits early Russian, (with special shorter spring) later Russian, Chinese, Yugoslavian, Albanian, and Romanians. $37.00 includes “First Class” anywhere in the U.S. and Canada.
http://www.murraysguns.com/images/fp_2008.jpg

rugerman07
February 14, 2009, 07:32 PM
Thanks for your reply. I just bought a Norinco SKS (haven't fired it yet). I also bought 120 rounds of Military Surplus ammo. However, I plan to use Wolf or Silver Bear ammo and just wanted to make sure I wouldn't freak out anyone at the shooting range with an accidental slamfire.

rugerman07
February 14, 2009, 07:36 PM
“Original” Russian style, newly manufactured, CNC machined and heat-treated 420 SS firing pin and “Wolff” spring are now available. Drop in fit with no alterations required. Fits early Russian, (with special shorter spring) later Russian, Chinese, Yugoslavian, Albanian, and Romanians. $37.00 includes “First Class” anywhere in the U.S. and Canada.
Will this fit a Norinco SKS?

QuietEarp
February 14, 2009, 08:11 PM
I would definitely disassemble the gun and give it a good cleaning especially the bolt and firing pin. The firing pin should freely "rattle" within the bolt. I believe that a gummy pin/bolt is responsible for the slam fire. There are several awesome videos on youtube that bring you through the SKS disassembly step by step. If you inspect the bolt and firing pin and it moves freely then I wouldn't be too concerned with a slam fire. It is a pretty solid design, I think most slamfires are a result of the cosmoline many SKSs come with. Good luck and be safe.

Ben Shepherd
February 14, 2009, 08:29 PM
Slamfires won't be a problem-IF you COMPLETELY disassemble the bolt and clean the firing pin channel with gun scrubber/brake cleaner and a small brush or pipe cleaner before you fire it the fist time.

csspecs
February 14, 2009, 08:30 PM
I just check that the firing pin still wiggles freely and don't worry about it... Keep a good grip :P

rugerman07
February 14, 2009, 08:47 PM
I would definitely disassemble the gun and give it a good cleaning especially the bolt and firing pin. The firing pin should freely "rattle" within the bolt. I believe that a gummy pin/bolt is responsible for the slam fire. There are several awesome videos on youtube that bring you through the SKS disassembly step by step. If you inspect the bolt and firing pin and it moves freely then I wouldn't be too concerned with a slam fire. It is a pretty solid design, I think most slamfires are a result of the cosmoline many SKSs come with. Good luck and be safe. Thank you for your reply. There was no visable cosmoline or any other lubricant on the Norinco SKS I bought today. However, just to be safe, I will remove the bolt and inspect it before I shoot it.

One more question. My Norinco SKS doesn't have a bayonet and I'd like to get one for cosmetic purposes (because it looks cool). Will any SKS bayonet, be it Norinco, Russian, Yugo, etc. fit it or do I have to get a Norinco spike bayonet?

esq_stu
February 14, 2009, 09:01 PM
My Norinco slamfires. It did when new and it still does when dirty. Keep the firing pin channel pristine.

WardenWolf
February 14, 2009, 09:03 PM
New Norinco SKS's have a sprung spring, as pictured above, to prevent this from happening. They issued a recall on the earlier SKS's and will refit them.

Anyname
February 14, 2009, 09:13 PM
"However, I plan to use Wolf or Silver Bear ammo and just wanted to make sure I wouldn't freak out anyone at the shooting range with an accidental slamfire."

I have only seen one slam fire in an SKS and the net result was that it went full auto for four or five rounds. If you have a full mag, it may be exciting all around.

briansmithwins
February 14, 2009, 10:40 PM
I've had 1 slamfire. Situation was 1 round of Federal ammo dropped into the chamber and the bolt was let go on it. It fired when the bolt closed. I inspected bolt and the firing pin moved freely.

Since I was following the rule about not covering the muzzle (and was at a range) there were no consequences.

BSW

Ben Shepherd
February 14, 2009, 11:09 PM
Guys, I've put dozens of SKS rifles back in service. WITHOUT EXCEPTION, every sks I've personally seen slam fire did not have the bolt dissasembled. Also WITHOUT EXCEPTION every rifle that has had the bolt dissasembled has not slamfired....FWIW.

Boiling won't do it. Sonic cleaning won't do it. Tear the bolt COMPLETELY apart and physically scrub the pin channel out before you put the rifle back in service.

Sunray
February 14, 2009, 11:26 PM
Slamfires are caused by improperly loaded ammo. Not the rifle.

jpwilly
February 15, 2009, 12:06 AM
Slamfires are caused by improperly loaded ammo. Not the rifle.

Wrong, Slamfires in the SKS happen because they are shipped with cosmoline in the bolt. The cosmoline gets tacky when it heats up and the free floating firing pin gets stuck in the "BANG" position! This happened to me after I had cleaned the bolt Thank goodness I had only two rounds in the mag when it went FA. It was stuck because even more cosmoline found it's way in there.

Slamfires in the M1 Garand on the other hand (or M1a) can be caused by high primers or even soft primer cups.

Stay safe.

mdThanatos
February 15, 2009, 12:11 AM
+1 on cleaning the firing pin channel and disassembling the bolt. Did it the first day I got my sks, over 5 years ago, and not a single slamfire. The pin should move freely, if you take the bolt out and hit the bottom of it, where the back of the pin is and it gets stuck in the forward position, it needs cleaning.

Sunray
February 15, 2009, 12:36 AM
"...shipped with cosmoline in the bolt..." That's not the rifle. That's the operator.
Can't imagine not thoroughly cleaning any new firearm. Milsurp or not. Mind you, I did it for a living, long ago. The shop I worked in got some literally mint(as in never fired, found in a warehouse somewhere.) early war-time, Portugese contract K98's(with a matching bayonet) that were jam packed full of cosmoline. Two days per rifle to clean it out. Things of beauty, so they were. Sold for $215Cdn in the early 80's. Lotta money then. Some guys bought two.

Gewehr98
February 15, 2009, 12:53 AM
Slamfires are caused by improperly loaded ammo. Not the rifle.

I watched a fellow die near Sacramento, CA due to a stuck firing pin.

It had nothing at all to do with improperly loaded ammo.

He didn't clean his new SKS, in particular that vexing firing pin channel, and paid the price when it went full-auto and rotated upwards, sending a round into his face and out the top of his head.

Would you like the newspaper article to verify, Sunray?

Google "William Ferrante" and "SKS" as your search terms.

http://www.google.com/url?sa=t&source=archive&ct=res&cd=0-0&url=http%3A%2F%2Fdocs.newsbank.com%2Fg%2FGooglePM%2FSB%2Flib00167%2C0EB045E0E9982FDC.html&ei=kq2XSe7-KOikgAeu79yWBg&usg=AFQjCNFjzDOn6X3QtAVGba1PotkcGpY6Vw

Matrix187
February 15, 2009, 12:57 AM
I heard about that incident awhile back. Very tragic... I try to tell people nowadays to clean their firing pin channel for their own sake.

2RCO
February 15, 2009, 01:39 AM
I think the moral of this story is proper care and maintenance can save your life!

Ben Shepherd
February 15, 2009, 10:39 AM
A couple things to note-

1. The complete bolt disassembly should only have to be done before the initial firing to remove all traces of cosmoline and check for burrs. After that normal maintenance doesn't require bolt disassembly.

2. The fist time you fire the rifle, only load 2-3 rounds. And worry more about controling the weapon than shooting accurately. That way if it does slamfire you'll have a no harm no foul situation instead of an out of control full mag dump. It's interesting to see and decidedly not cool when you release the bolt and the whole magazine dumps downrange as soon as the bolt goes forward before you even touch the trigger. The shooter better sure as heck have control of that rifle.

G98- Thanks for the link. Tragic situation there. As many as I have seen slamfires in caused by not tearing the bolt apart, I figured somewhere something like that had happened.:( So every time someone asks how to clean their new SKS and folks start telling them that bolt disassembly isn't really needed I feel like screaming.

One other rare cause of slamfires in an SKS-
If the firing pin pierces a soft/high primer, it can stick a piece of the primer cup between the pin and the bolt, sticking the pin forward. I've seen that one half a dozen times. Once again-With a new type of ammo/new SKS, only load 2-3 rounds. Inspect the primers for piercing. If they are-DO NOT continue using that ammo in that gun. You WILL have a slamfire, you're playing Russian Roulette.

280shooter
February 15, 2009, 12:54 PM
I use Mineral spirts to clean off all the cosmoline, U can see it melt away, using a brush,I use a 5 gal bucket. put some in a small plastic tub and run it down the barrel.over and over, it cleans all that junk right off. I also recyle it.pour all the spirts back in the container, let it sit over night, all the grease goes to the bottom,slowely pour the spirts back into a clean container,and soak all the small parts.You'll be surprized how well this takes all that cosmoline and grease off..

carbine85
February 15, 2009, 01:27 PM
My Russian has slam fired twice when charging the first round:what:. Very scary to say the least. It has the spring type firing pin. I found the bolt assembly was gummed up so I cleaned it. It hasn't slam fired since but I also don't let the bolt slam home when charging the first round anymore.

Ben Shepherd
February 15, 2009, 01:45 PM
Carbine85-

Think about it, you letting the bolt go home rapidly is a whole lot less violent than the rifle does to itself when operating normally. Did you tear the bolt apart ALL the way before you put the rifle into service?

If not, I'll give you 10:1 odds that you have cosmoline left up right behind the bolt face in the pin channel. And if you are storing the rifle hammer forward(as you should) it's sticking the pin forward in the cosmoline(that's more than likely slightly warm and soft from firing) then the rifle cools off, the pin sticks forward in the cooled and hardened cosmoline, and the next time you take the rifle out, the first time you drop the bolt you get a mysterious(and it's ALWAYS the FIRST round) slamfire that knocks the pin loose, and the rest of the day you have no slamfires.

How'd I do?:D;)

Funderb
February 15, 2009, 01:50 PM
I have never had this happen to me, but can attest to firing pin slight imprints on some primed cases I made to see if I could set one off.

Hard primers are the way to go.
Wolf ammo and the russian manufacturers will do fine, I don't expect that you'll be shooting matches with this.

jlmurphy
February 15, 2009, 02:33 PM
You should avoid letting the bolt drop on a round in the chamber on a rifle with a floating firing pin. It should always be stripped from the magazine, the extra force required slows the bolt and lowers the inertia of the loose pin.

rugerman07
February 15, 2009, 06:37 PM
In other words......Don't pull the charging handle back and release it? Pull the charging handle back and drive it forward while still holding on to it?

jlmurphy
February 15, 2009, 10:31 PM
In normal operation the bolt, when coming forward, strips the top round from the magazine, this requires energy and slows the bolt. If you place a round in the chamber and release the bolt it will travel much faster and the firing pin can hit the primer with enough force to detonate it.

WardenWolf
February 15, 2009, 10:35 PM
However, as was already stated, you need to keep it clean. If the firing pin sticks in the forward position, it can contact the primer prematurely even during a magazine strip situation, and can fire out of battery.

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