# SKS FTF Mystery



## dheat (Jul 27, 2005)

I took my Yugo SKS plinking with some friends recently. It failed-to-fire (FTF) when someone else was shooting it (two FTFs in a row and third FTF later). In each case, I reinserted the rounds into the rifle, fired it myself and each round fired. After shooting hundreds of rounds through this rifle, these were the first FTFs.

I inspected the rounds before the second attempt at firing. There was an obvious firing-pin indentation in each round.

Other factors:


I was using 4-5 year-old Wolf ammo
I have an aftermarket (Murray), spring-loaded firing-pin installed*
The bolt face had been "smoothed" by a gunsmith (Murray)*
Two FTFs with non-detachable magazine from a different rifle
One FTF with aftermarket, detachable magazine*
* This was the first time the rifle was fired since this modification.

What could be the problem(s)?


The spring-loaded firing-pin isn't striking the hard-primered Wolf ammo hard enough
"Old" ammo (how long is it good for?)
Different shooters
The magazine well of the original wooden stock had been relieved slightly to accommodate the aftermarket, detachable magazine
All of the above
Other
I don't understand how the shooter would effect FTFs, but different shooters was a factor. I understand how modifying the magazine well might cause failures-to-feed, but not failures-to-fire, regardless that's a factor. Nevertheless, I could be wrong on both counts.

What do you think?

Thanks,

Doug


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## dkhern (Nov 30, 2012)

ammo or fireing pin. with dimple on primer its either a light hit or primer problem either one wouldnt keep them from fireing on 2nd try

ammo is good for years good luck


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## Bearfootfarm (Jul 13, 2006)

It's probably a combination of bad ammo and a dirty gun


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## Usingmyrights (Jan 10, 2011)

You've got me on that one. I dont know how stuff the spring is and if you compared the strikes on the primer to spent shells to see if it may have been a light strike.


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## InvalidID (Feb 18, 2011)

Was the guy bump firing or anything fast like that? Kinda like a limp wristed shooter can cause a FTF in a handgun maybe?


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## dheat (Jul 27, 2005)

The rifle was clean as I was hoping to interest my friends in buying it. That hope went south with the FTFs.

The other shooter was not bump firing. He was shooting standing.

Thanks


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## Hollowdweller (Jul 13, 2011)

One time I was having that problem with my Russian. I took it apart and cleaned it and no luck. Took it apart again like 2 more times looking and it started shooting fine! Go figure.


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## GREENCOUNTYPETE (Jul 25, 2006)

what did you oil the firing pin channel with ?

might start with taking the bolt out soak it in 50/50 mineral spirits and ATF over night 

if it seems very shooter specific watch does the other shooter follow through with the trigger or just try to let it break and not follow through with the pull to the rear then let it go forward to reset


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## dheat (Jul 27, 2005)

GREENCOUNTYPETE,

Beyond residual CLP, the firing pin channel doesn't have any lubrication. Should it? I never lubed it before installing the new FP and never experienced FTFs.

Regardless, I'll give it a shot. What do you recommend?


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## GREENCOUNTYPETE (Jul 25, 2006)

It may not be your problem but it doesn't cost much and it can't hurt most people already have some paint thinner or mineral spirits in the garage and a partial bottle of automatic transmission fluid 

my cousin went to take a shot at a deer he should have had this year , click , he had oil that had gotten into the firing pin channel and glued the firing pin in place his fired on the second try 

other things to look for burs on the firing pin , or at the bolt face 

sometimes it is the tiniest thing that take you from working to not if your firing pin is .002 to short and a little gunk is in the way or a bur you can't even see but can feel when you drag your finger over it or that ammo that head spaces off the shoulder is .002 short things add up to just enough to work most of the time but not all the time.


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## watcher (Sep 4, 2006)

As someone pointed out its either the primer or the firing pin. Seeing as how the malfunction didn't occur until after your firing pin work I'd say that's the most likely problem. As to what it could be. . .spring a bit too long effectively making the firing pin a bit too short, the pin is a bit too short or the spring it too stiff. Measure the old pin and the new one with a very accurate device. If they are the same then the problem is most likely the spring.


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## seedspreader (Oct 18, 2004)

Gas piston seal. I've fixed mine with a paper clip. Yes it worked.

http://www.sksboards.com/smf/index.php?topic=4191.45

If it lets you get a good price on the SKS, buy it. Don't worry, it can be fixed no matter what it is... cheaply and easily.


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## GREENCOUNTYPETE (Jul 25, 2006)

some of the confution here is miss use of common terms 

FTF is typicaly Failure to Feed 

FTE failure to extract 

what your describing is a Misfire = click no bang

some others are double feed 

stove pipe 

but in reading thru what your describing it's a misfire


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## dheat (Jul 27, 2005)

seedspreader,

I had a gas valve leak (it's a Yugo) early on. The leak caused stove-pipes, not misfires (thanks for the correction GREENCOUNTYPETE). I did use the paper clip method to diagnose the problem, but I solved it with a new, slightly larger gas valve. I haven't had any problems like that since and have shot several hundred rounds through it.

Thanks,

Doug


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## dheat (Jul 27, 2005)

All,

thanks for the input. I'm going to give the FP, FP channel and spring a good looking over and cleaning. If that doesn't work I may shorten the FP spring.

Thanks again,

Doug


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## sandc (Apr 26, 2010)

Did you have Murray cut the bolt for the detachable mag to make it like the type M, or just reface it?


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## dheat (Jul 27, 2005)

sandc,

Murray just refaced it.


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## bluetogreens (May 31, 2010)

hrrm spring loaded firing pin not in original design. sorry as someone who enjoys "bubba'ing" as much as the next guy but the spring loaded firing pins are a solution looking for a problem IMHO.


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## sandc (Apr 26, 2010)

I have to agree about the spring loaded firing pins. I never had any problems until I installed one and they went away as soon as I swapped back to original


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