Avoiding slam-fire on SKS?


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Odnar
December 29, 2006, 02:06 PM
I took my Yugo SKS to the range for the first time this fall and had a slam-fire when I released the bolt. (Thank goodness for good handling habits) I haven't fired it since. Is there any kind of a spring resisted firing pin or similar kit that I can get to help reduce this risk? I don't think the bolt assembly was dirty or gummed up. The gun was thoroughly cleaned prior to taking it out, and had only had around 40 rounds fired through it that day. I lubricate sparingly.

Thanks.

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ZeSpectre
December 29, 2006, 02:16 PM
Read this http://www.murraysguns.com/sksown.htm

Even if you don't want to get one of his "sprung" firing pins, the cutaway views are great for showing how cosmoline gets stuck in the firing pin area and can be a challenge to clean out.

Just fyi, I did buy one of his kits because I figured it'd be cheap insurance against slamfires and soft primers. My SKS shoots like a dream with that pin.

Jackal
December 29, 2006, 02:30 PM
Funny thing. I actually have seen rifles modded with a bolt release and the firing pin epoxied in the "armed" condition just for the purpose of being a full auto.

Odnar
December 29, 2006, 02:38 PM
When I got the rifle it was absolutely stuffed full of cosmoline. I completely disassembled the bolt and soaked the components in solvent, then cleaned them very, very well. The interior of the rifle is completely clear of cosmoline. The wood stock, however, is another story.:D

ZeSpectre: Thanks, that's what I was looking for!

Nil
December 29, 2006, 03:51 PM
That's odd. I thought the sole reason for slam fires was a gunked up firing pin. I always disassemble my bolt after the range and clean it out to avoid such an occurence, but do I still have to worry about a slamfire even with such a cleaning regimen?

ZeSpectre
December 29, 2006, 03:57 PM
As I understand it even a clean firing pin can potentially become mechanically "wedged" into the bolt causing a slamfire (or more typically a "doubling" with the pin being knocked loose after the second round).

I also understand that this is extremely rare with a clean gun in good condition. Still I decided (as mentioned above) that Murray's pin kit was just cheap insurance.

MikeH
December 29, 2006, 04:08 PM
Funny thing. I actually have seen rifles modded with a bolt release and the firing pin epoxied in the "armed" condition just for the purpose of being a full auto.

This is a common design on full-auto weapons that fire from an open bolt. However, they are made to do so safely. A semi-auto rifle with firing pin stuck forward will likely fire out of battery, and that's gonna hurt the shooter far more than the intended target.

joplinsks
December 29, 2006, 11:14 PM
Remove the bolt and shake it back and forth. The firing pin should rattle freely inside the bolt if it's cleaned properly. If it doesn't, you'll get slam fires.

Also, the Yugos are made to shoot mil spec ammo with tough primers. The commercial non corrosive stuff is easier to set off and has a tendency to slam fire more easily due to the Yugo's free floating firing pin design.

MErl
December 29, 2006, 11:50 PM
As I understand it even a clean firing pin can potentially become mechanically "wedged" into the bolt causing a slamfire (or more typically a "doubling" with the pin being knocked loose after the second round).

I also understand that this is extremely rare with a clean gun in good condition. Still I decided (as mentioned above) that Murray's pin kit was just cheap insurance.

I had that exact thing happen with a SKS...

a piece of primer got blown into the firing pin channel somehow. pin stuck forward, doubled. fired again after checking things and another double. home I want to take it apart.. where did that little piece of metal come from?

(I'm guessing it was a primer chunk)

sctman800
December 30, 2006, 01:49 AM
I put a Murray's modified firing pin in mine as cheap insurance, especially since I reload 7.62x39. Yes, the tapered firing pin in a tapered hole is prone to stick. Jim.

ZeSpectre
December 30, 2006, 06:57 PM
sctman800,
No more concern over softer primers is a nice plus as well :D

Smokey Joe
December 31, 2006, 01:24 AM
Odnar--There is another thing you can do to prevent slam-fires besides cleaning the firing pin channel, and getting a Murray's firing pin put in-- (Both of these are a Good Thing To Do, IMHO.)

If you reload for yr SKS (and if you reload at all, why wouldn't you?) you can use CCI #34 primers. These primers are "tougher" than the "regular" primers, and are made specifically for rifles with floating firing pins, the SKS and the Garand among them.

Had a slam-fire myself once with an SKS. I agree, good gun handling habits are a MUST when shooting these guns (well, as with ANY firearm!) so all I got out of it was a surprise. But it did bring home the point that that firing pin can't be too clean.

Now as to lubing the pin, there are at least 2 schools of thought. Some say don't lube it at all; lube collects dirt; dirt will cause the pin to jam. Me, I lube the pin, using the thinnest oil I can find: Kamo Kroil. Seems to be working for me so far. I do check, is the pin still loose in there, every range trip.

BoySetsTheFire
December 31, 2006, 11:30 AM
Kano Kroil - that's some good stuff. I (and others) mix 50% Kano Kroil and 50% Shooter's Choice (or Hoppe's #9) for a great barrel cleaner. But I would not use Kano Kroil in the bolt. I've heard that Kano Kroil can be a little hard on the metal. I would use Kano Microil, from the same company, in the bolt. This is a finer oil designed for delicate instruments.

But I would not rely on a lubricant in the bolt, or a spring. I would want to find out why the rifle slams. Could be the pin is slightly bent. Then you would replace it with the spring kit and figure that was the solution, when it wasn't. I have fired thousands of rounds from an SKS with no problems.

SlamFire1
December 31, 2006, 02:42 PM
Slamfires are very real phenomena with semiautomatic mechanisms. People attribute slamfires to mechanical things, like stuck firing pins, grease in the firing pin hole, hammer following the bolt, all of which will cause a slamfire, but when it comes to primer sensitivity, folks just don’t see it.

Imagine this, you have a primer and a firing pin with sufficient energy to ignite the primer. What happens when the firing pin hits the primer?; the primer goes off. Imagine you have a free floating firing pin attached to a rapidly moving bolt carrier and a round is being fed into the chamber. And before the trigger is pulled the firing pin hits the primer. What happens?; if the firing pin has sufficient energy to ignite the primer, well the primer goes off. If the primer goes off before the bolt is in battery you have an “out of battery” incident. That is likely to be a destructive event.

The SKS with a free floating firing pin is particularly susceptible to slamfires. So is the M1 Garand and the M14 mechanism. The original M16 configuration had slamfires in service so the military redesigned the firing pin to make it lighter. If you notice the FN/FAL firing pin is spring loaded, so are some of the original SKS designs, and so are the AR10 designs. All needed to keep a sensitive primer going off when hit by a rapidly moving firing pin.

The military could specify extra insensitive primers, and probably did for those military SKS’s, and of course the military issued their ammunition to their soldiers, who used only that ammunition in their service rifles and all was well. But when these things get surplused, put in the hands of civilians who use commercial ammo (which have the most sensitive primers around), or someone elses military ammunition, well you have a case of tolerance stack up don’t you.

The cure?, find ammo that works, make ammo that works, or get the weapon modified.

Smokey Joe
December 31, 2006, 03:13 PM
BoySetsTheFire--I've heard that Kano Kroil can be a little hard on the metal.How do you mean that?? It's a lubricant, isn't it? Could you provide more details, and mebbe a reference?

The stuff works as a thin lubricant, IMX, and i use it in my SKS bolt (as stated) and also on pistol slides, especially in cold weather. It just seems to work. My 1911 gets a little sticky with any thicker lube, in the cold, but KK makes it slam open and shut with a will.

So, sir, please tell me in what way I'm being hard on my guns. I don't normally damage equipment on purpose, and I thought I was improving their function.

I'm not challenging your claim--I want to know more!

Dave Markowitz
December 31, 2006, 03:53 PM
But I would not use Kano Kroil in the bolt. I've heard that Kano Kroil can be a little hard on the metal.

I call BS. It's a penetrating oil. Kano specifically recommends it for use in freeing up rusted parts and preventing corrosion. Further, if it is harmful to metal, why are you putting it in your barrel.

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