Duds to Expect

GuitarmanNick · Aug 6, 2017

I put some Russian 7.62 x 39mm through my SKS today and had a couple of dud rounds out of 100. The primers were impacted and appeared normal in every way, but the rounds did not fire. This ammo was just removed from it's sealed spam can a couple of days ago and is dated 1975.
Can anyone give me an idea of expected failure rate based on their experience with similar ammo?
This is my first experience with rounds not firing, so I have no idea if some failures should be expected when using imported ammo.

Art3 · Aug 6, 2017

I don't have a direct answer...but why should that stop me from chiming in

? Are you sure they were good hard primer hits? Any chance there is any sort of gunk or anything slowing down your firing pin? Did you put them back in and have another try?

Two out of a hundred seems pretty high to me...even for cheap rimfire.

I don't recall ever having a dud in my imported ammo, although I think all my 7.62 x 39 is fairly new. I've shot 'Merican made ammo that was almost 80 years old that went off every time. I believe most of the HXP (Greek) being shot today is from the sixties, and I haven't heard of any issues.

Sorry I'm not much help... :shrug:

GuitarmanNick · Aug 6, 2017

Both rounds were cycled a second time and the primers were struck. The marks are normal in appearance. I weighed the rounds and they are the same weight as the rest of the batch based on several samples. This means they must have powder in them. I suspect the primers are bad, but I have never seen this happen before.
There is no sign of any corrosion on any of this ammo. It looks like it was made last week so I was expecting it to be okay.
I also tried it in 2 different SKS's. My buddy was shooting when the first round failed. I cycled that round in my SKS when I was shooting to rule out a problem with his gun. It was the first time he had shot his and mine has been fired without any problems before. The result was the same for both guns so I look to these particular rounds as having an issue.
I have little experience with imported ammunition but that is changing with some of my recent acquisitions.

tallen702 · Aug 7, 2017

GuitarmanNick said:
Both rounds were cycled a second time and the primers were struck. The marks are normal in appearance. I weighed the rounds and they are the same weight as the rest of the batch based on several samples. This means they must have powder in them. I suspect the primers are bad, but I have never seen this happen before.
There is no sign of any corrosion on any of this ammo. It looks like it was made last week so I was expecting it to be okay.
I also tried it in 2 different SKS's. My buddy was shooting when the first round failed. I cycled that round in my SKS when I was shooting to rule out a problem with his gun. It was the first time he had shot his and mine has been fired without any problems before. The result was the same for both guns so I look to these particular rounds as having an issue.
I have little experience with imported ammunition but that is changing with some of my recent acquisitions.

Must have been produced the day after the local stores finally got their shipments of Zhigulevskoye after a 2-year back-order.

All kidding aside though, 70's milsurp soviet 7.62 of any type has extremely hard primers (like, harder than modern Russian primers). So hard that many US-made 7.62x39 firearms like the older Ruger Mini-30s will break firing pins. My guess is that they're just exceptionally hard primers and won't fire unless kicked by a horse.

Only other thing I can think of is if the primers are set just a little too deep in those two rounds for some reason.

rob-cubed · Aug 7, 2017

I've gone through tons of spam cans of 7.62 (mostly in AKs) and can only recall one instance of failure to fire. It's typically pretty reliable stuff.

Maybe Ivan was working the line, and had a bit too much vodka for lunch?

Sounds like a batch of bad primers made it into your can.

tallen702 · Aug 7, 2017

Meant to ask, have you inspected your firing pin recently? Is it a free-floating one, or did you do a spring-install? Is the tip worn?

GuitarmanNick · Aug 7, 2017

I have inspected both firing pins and they are fine. Both SKS's are Chinese and have original matching parts. One was well worn and most likely saw battle and the other is like new. I recently serviced both and did trigger jobs on them, but only changed the sear and hammer to get positive engagement and shortened the trigger travel. Gave things a good polishing, too. Triggers both function smoothly and trigger pulls are still about 6 pounds, but much improved. Both still have all of the original springs so they should handle any hard primers with ease. I knew we would be using ammo that would probably have them so I did not lighten any springs. I just made the triggers safe and smooth.
I have fired Chinese and Yugo ammo in mine before with no failures. This is the first Russian I have tried.
I don't like the idea of installing a spring on the firing pin. I have read of a broken primer causing an SKS firing pin spring to break causing the firing pin to become stuck fully forward and sending the weapon into full auto mode because of slamfiring. I never had one in my M-16's or AR's and they are also free-floating. Millions of Chinese never needed to modify theirs, why should we reinvent the wheel?
If you own an SKS, you should educate yourself on the weapon and how to check it thoroughly and correctly and clean it properly. I am OCD about the care and maintenance of my weapons. If I one day need to depend upon one of them for my life, I want it to work as intended without fail.
Just the way I was raised.

tallen702 · Aug 7, 2017

GuitarmanNick said:
I don't like the idea of installing a spring on the firing pin. I have read of a broken primer causing an SKS firing pin spring to break causing the firing pin to become stuck fully forward and sending the weapon into full auto mode because of slamfiring. I never had one in my M-16's or AR's and they are also free-floating. Millions of Chinese never needed to modify theirs, why should we reinvent the wheel?
If you own an SKS, you should educate yourself on the weapon and how to check it thoroughly and correctly and clean it properly. I am OCD about the care and maintenance of my weapons. If I one day need to depend upon one of them for my life, I want it to work as intended without fail.
Just the way I was raised.

I don't recommend the firing pin spring myself due to the fact that it's extra force that the hammer is required to overcome to initiate firing. It's not much, but it's there. That's why I was asking if you had one installed as that small amount of force could be just enough to prevent a solid strike on a hard Russian primer. I wasn't impugning your knowledge of the arms either, simply trying to think of all the possible variables to rule out possibilities.

Combloc · Aug 7, 2017

Please post some pictures of your 1975 Soviet ammo please! Tin, interior packing, full round and head stamp.

ken792 · Aug 7, 2017

Yeah, 1975 Soviet ammo is better for collecting than shooting. People pay stupid amounts for that stuff, especially if it were a sealed tin. You can buy a good bit more modern Russian commercial with the money that will go off.

Erno86 · Aug 7, 2017

I experienced a Wolf {camo box} 5.56 x 45 dud in one of my AR's yesterday; with a normal primer indentation. I am not going to depend on this make of ammo in any critical situation --- Same goes for Tula.

molonlabe · Aug 7, 2017

Unfortunately not knowing how it was stored affects Ammo. It must be stored in a cool dry place. Of course sealed cans are not so affected by moisture but may rust. That being said repeated seasons of hot storage sub zero storage will cause the condition you described. I trust my reloads over what I find at a gun show unless it's a reputable dealer.

Erno86 · Aug 8, 2017

About 3 years ago...I had a squib load with a 7.62 x 39 Tula round with my AK --- The primer went off and the powder looked like it absorbed some kind of liquid; with the bullet lodged just forward of the chamber.

GuitarmanNick · Aug 8, 2017

I can say that the can was still sealed and I saw no sign of moisture on any of the boxes. I have no idea of the temperatures it may have seen, but the can looked good on the outside, too.

As for this ammo being collectable, I don't think this has any special value. For those more knowledgeable, I am sharing some hyperlinks to some photos.

Headstamps is simply 7.62 x 39 and 1975. No other markings.

https://www.dropbox.com/s/zjeq2wrjy24q09b/2017-08-07%2012.25.29.jpg?dl=0
https://www.dropbox.com/s/205uoo4e6fkb2wn/2017-08-07%2012.25.52.jpg?dl=0
https://www.dropbox.com/s/brn0wjdrf1aj76s/2017-08-07%2012.27.14.jpg?dl=0
https://www.dropbox.com/s/t91kg78pclb3ujc/2017-08-07%2012.28.53.jpg?dl=0
https://www.dropbox.com/s/7mb1ts3herhh13z/2017-08-07%2012.29.03.jpg?dl=0

Sorry for the quality of the shots.

ken792 · Aug 8, 2017

Oh, that's just Russian commercial, probably from the 90s. I don't think 1975 is the date. Ulyanovsk still makes ammo. Tulammo and Herters 7.62x39 are made by them.

GuitarmanNick · Aug 8, 2017

1975 is stamped on each round. Not sure what else it could be but the year of production.

ken792 · Aug 8, 2017

I don't see a 1975 on the round pictured, just a 7.62x39 and a Ulyanovsk logo.

GuitarmanNick · Aug 9, 2017

Sorry, I was thinking of some M67 Yugo that has the 1975 stamped on it. You are correct about the logo.

240 towles · Aug 9, 2017

Eldest son

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