UH-OH! Slam Fire!!

[Yukon227]

Been meaning to order a spring loaded firing pin for my chinese SKS for a while now, as it prevents the slam-fires caused by the free floating firing pin. Mine has never had a slam fire problem, until tonight
I shot 2-10 round stripper clips through it, the first clip had a 2 shot slam fire, the second clip had a 4 round slam, I stopped and checked and the pin wasn't stuck forward. Soooo, I'm ordering the Murray's kit this weekend, unless someone has another suggestion. I've done a lot of research and it seems this is the best option.
Thanks

 

[sloughfoot]

I believe in the Murrays firing pin spring. I have it in my SKS's.

However, what you are describing is not technically a slam fire.

A slam fire is usually just the first round, not multiple rounds.

If you are getting multiple discharges, you are describing full auto fire. If the trigger group is unmodified, it is extremely unlikely that it is going full auto from that.

What is more likely is that you are not pressing the trigger fully to the rear and holding it back as the rifle fires and goes into recoil. If it is happening when you squeeze the trigger.

I hope I haven't made too many assumptions, unless the firing pin is frozen forward, a true slam fire only discharges one round.

It is called "floating the trigger" and is a fun way to mimic full auto fire with a semi-auto rifle.

I have done it during a match with my M1 Garand by not holding the trigger all the way back during the prone rapid fire stage of a Garand match. The first shot was on target, the second shot went way over the target. You can empty a 1911 in about a half second by floating the trigger.

 

[Tombs]

Considering he hasn't listed the ammo yet, you can't assume anything.

It could be some winchester stuff with soft primers.


Free floating firing pins aren't usually much of a problem. Most center fire military rifles use free floating firing pins.

 

[Yukon227]

It actually was some winchester white box stuff, the only other ammo I have put through it has been wolf or silver bear or norinco with no issue

 

[Tombs]

It actually was some winchester white box stuff, the only other ammo I have put through it has been wolf or silver bear or norinco with no issue

Well, there's your problem.

That winchester ammo isn't really marketed towards guns like this, and has soft primers.

Plus the added cost of winchester makes it kind of pointless to use. Save your money and shoot the cheap stuff.

 

[Yukon227]

I bought a big bunch of ammo from a guy I work with and this and some UMC was in with it, just 3 or 4 boxes, figured I'd shoot it up, never thought about soft primers

 

[sloughfoot]

OK, tell me if you are getting multiple discharges when you drop the bolt on the the first round or if you are getting multiple discharges when you squeeze the trigger.

Winchester primers are not "soft", whatever that means. I use winchester primers precisely because they are real close to military primers in their hardness. Remington primers too. Thousands used over the years with no slam fires in floating firing pin rifles.

Let us really zero in on what is happening here.

 

[Yukon227]

just when I squeeze the trigger, and only tonight with this ammo, I usually shoot cheap stuff

 

[Wild Deuce]

Interesting ....

The only slamfires I have ever had were with Winchester White Box ammo ... 62 grain .223 Rem to be exact. It would happen while releasing the bolt as well as doubles after taking a shot. Other factors were in play but they were slamfires that occured only with the Winchester ammo.

 

[nipprdog]

I bought a big bunch of ammo from a guy I work with and this and some UMC was in with it, just 3 or 4 boxes, figured I'd shoot it up, never thought about soft primers

The only time my SKS slamfired was with UMC. Fwiw.

 

[TwinSix]

Murray's FP

get the Murray's FP and give yourself a piece of mind... Mechanically try to eliminate as many "known" causes as you can.

And many people have suggested not using the domestic 7.62 ammo as they have the so called soft primers. Is this true? Well, we all have read it on the internet, so it must be.

Try the murrays FP with the same ammo again, in a control test. That is if you feel comfortable doing so, and report back. I am interested to know the outcome.

I put the Murrays FP in my SKS to eliminate the potential for the slam fire. If there is another possible cause, I would like to eliminate it as well.

 

[ghostpoint]

I was looking to get Murray's firing pin myself just like you said to eliminate any possible issues. Never had any problems from my paratrooper but why wait until there is.

On a side note any use the buffer block to cut back receiver wear from the bolt slamming into it? If so ever have any failures because of it?

 

[paperboy]

I shoot nothing but Wolf or Brown Bear in 7.63x39 and have never had what you describe happen. I do however ALWAYS point the muzzle low and down range EVERY time I load up. I have never had a slam fire but that doesn't mean it can't happen.

 

[sgreen3]

+1 for the Murrys kit, I have one in my SKS

 

[Yukon227]

get the Murray's FP and give yourself a piece of mind... Mechanically try to eliminate as many "known" causes as you can.

And many people have suggested not using the domestic 7.62 ammo as they have the so called soft primers. Is this true? Well, we all have read it on the internet, so it must be.

Try the murrays FP with the same ammo again, in a control test. That is if you feel comfortable doing so, and report back. I am interested to know the outcome.

I put the Murrays FP in my SKS to eliminate the potential for the slam fire. If there is another possible cause, I would like to eliminate it as well.

This is my plan, I'm leaning towards the ammo since I've put 250 rounds of everything else through it with no issue. Once I get the pin I will take pics and post the replacement.

 

[jmiller676]

Murrays FP is great. The problem with the SKS bolt (Not sure if others are like this) is you have a tapered pin going into a tapered hole. Anyone that has minor mechanical experience knows this is a good way to get the pin stuck, especially since we rarely clean our rifles , and would result in the slam fire. Like I said not sure if all military CF rifles have the tapered pin/hole combo but know that thats a problem with the SKS.

 

[kludge]

unless someone has another suggestion.

clean it?

 

[jmiller676]

clean it?

How do you clean an SKS? Throw it in the river and load it up with corrosive ammo and shoot to dry?

 

[Yukon227]

clean it?

Hahaha...it has no cosmolene left in the metal. I hosed it with my pressure washer to get it all out