SKS: Bolt Mod - Popped Primer Fix (HD)

[@nsz85]

So far, so good. After I did this mod, I have not had any further issues.

[@Murraysguns]

As others already said, excellent video and excellent work on the bolt! You can still see the original machining marks on the bolt face and that is a perfect job of stoning it flat. While this was our best effort at stopping popped primers for years, and is SOP when we install a FP Kit, it didn't work for everyone. But we now offer our new "Neck & Throat" chamber reaming service that does put a stop to popped primers once and for all. The bolt face condition, and the larger than usual FP hole size do contribute to the problem, but we've discovered that the real culprit is "spikes in the peak chamber pressure." And we also offer the "N & T" reamer, made by Manson, to anyone that works on SKSs. *The 82 degree countersink bit just leaves a better angle to the cut than a 90 degree.* (just our opinion) NSZ, get in touch with us about a special deal for you in return for the recommendation and video.

[@damianroberts4330]

I love ya'lls firing pin and spring mod. I bought one and am super thrilled about it. I'll be ordering more of them just in case one busts!

[@xs650abear6]

Thanks for the video. My local gunsmith wanted $60 to stone and countersink my SKS bolt firing pin hole. I akready had the stone so a trip to Lowes hardware and i found the 82* countersink for $9. It took all of 20 minutes to stone and countersink the hole. Thanks once again.

[@Siunloader]

Excellent excellent excellent video! My bolt looks same as yours and cuts out perfect little circles from the primer. I ordered up my materials and will be trying this out when they arrive. Yours was the only video that had a detailed fix that I could find. Great vid!

[@nsz85]

Thank you! Let me know if it works out for you :)

[@jomikalatinofortrump7661]

did it fix the problem on your sks?

[@nsz85]

I am glad you liked it! I have a couple planned shoots coming up and i will have an update soon!

[@Superplums]

Great video! I figured this out myself after going through the exact same problems. Number one cause of this is dry firing the SKS and those Murray's pins always break and make it worse.

[@nsz85]

You are welcome, I am glad you found it helpful! I do not frequent the SKS boards and am not a member of such forum. Sorry!

[@kevaillant]

Well I just bought a Simonov SKS 1952 for my first weapon and you Sir are my new Mentor!! Lol Awsome work

[@TheHappyShootist]

Thanks for an awesome and well done video! I just got a sweet '52 Russian with a Murray's pin installed and the pin spring broke into pieces after some 50 rounds causing light strikes and then popped primers until the pin jammed back but didn't break. Finally got all the broken spring parts out of the bolt along with a popped primer that got in there so the pin floats freely now. Cleaned the chamber really good but now I'm worried about popped primers if the pin goes too far without its safety spring.

[@mmelgoza1983]

Did you dry fire your rifle at all? I did, not excessively but a bit, because I was told for many years that dry firing a centerfire was always okay. Now I know better, every design is different. Since the pin and pin channel are tapered I can only conclude that that's how it happened. My yugo bolt definitely has a volcano firing pin hole. It's been years since I last shot her and had popped primers for days but I finally want to fix her up. Gonna be trying this method, thanks for this video!

[@captainmahvelous7068]

Very useful and dead on accurate instructions. I am an amateur SKS gunsmith and I agree with everything you did. Thanks man!

[@zlatanzifovskijr4576]

Not sure if anyone had this issue after doing this, After shooting about 80 plus rounds out of my sks it looks like the primers are a bit bulged or swelled (they’re not popped) just weird looking, not sure if this is normal because of the countersink?

[@richardlahan7068]

Having to replace my Type 56 SKS bolt for this exact reason. I've had primer fragments getting blown into the firing pin hole in my bolt. I currently have a Murray's firing pin (minus the spring) in the bolt because Chicom firing pins won't fit into the firing pin channel. They go in about halfway and stop. Hopefully, the new bolt fixes the problem.

[@Sector001ked]

Finally, a simple but effective solution! Thank you!

[@QapNPoo]

Hey, I have an old chi-com SKS, which doesn't have this problematic bolt-face mound, but yesterday I was firing it for the 2nd time since I purchaesed it and am fairly certain I had a primer pop. There was alot of burnt and burning powder on the bolt, the pin, and inside my receiver, and it was smoking from the action. What else could be causing this, because I do not want to have to buy a surplus of pins just to be able to use my rifle. Any suggestions would be extremely appreciated.

[@nsz85]

My only advice is to bring it to a gunsmith.

[@QapNPoo]

nsz85 thank you, no. I think i will make a video as I show how to cut a new pin. This is disappointing, I thought you were a gunsmith since you have videos on gunsmithing. But to pay 40 bucks for a new pin pin? Pay someone to fuck with it until a solution is found?When i could do that myself? Thanks for the advice, but it sucks.

[@QapNPoo]

nsz85 Wow, that response wasn't meant to sound so dickish. But I stand by it.

[@blacknightum]

im going to have to d this i shoot 120 rounds the other day and about 25 had light primer marks that did not fire from tula ammo i have a murray firing pin installed and after words when i cleaned it i noticed it turned it self back into a free float firing pin i think the spring broke inside due to using 30 round mags and the last mag i used i shoot rapidly. great vid i have to give it a try especially with the norinco sks

[@DonziGT230]

You could cut down some of the stoning by running the countersink first, then again afterwords just to de-burr. As for the stoning, you could use a round stone for a dremmel with the shaft in the hole to keep it flat so you don't have to worry about nicking up the bolt face, just spin it with your fingers or use a rubber faced disc and a drill to spin it. Never had to do this, just some thoughts.

[@ernestinebass4371]

Tried your ingenious upside down Dremel tip, and it works! Got rid of that blasted "volcano lip" and produced a perfectly flat surface to boot! Thanks!

[@ClawSpike]

Fantastic video. Nice and sharp and bright camera work. Thanks.

[@russmonte5176]

Also brass cased American ammo has a different primer.boxer berdan.american tends to pop

[@mrmathewhill]

your bolt face before modification looks nothing like the bolt face on my Russian sks. the firing pin hole looks bigger and blown out. I would suspect that the bigger firing pin hole would allow the tapered firing pin to slide too far forward, over deforming the primer and loosening it out of the cartridge. I'm curious to know if your modification of the bolt solved the problem or made it worse? Thanks for the video. I will have to watch and see if the bolt in my sks starts to deform in the same way. maybe your bolt was just a dud from the factory.

[@brandonsusich]

NSZ85,...... I think this might be my culprit here. After reading what Murray's has added to their page recently as well, I see that this is where you got this information from. My question to you would be, what about the bolt carrier and the service they do to that? Did you do that yourself as well??? If so how??? I appreciate your awesome videos by the way, super informative and you do a great job making everything very visible on the camera. Great videos!

[@mrmathewhill]

nsz85 never mind my previous comment. i just watched your video on the Murray's sks firing pin. the pin caused the deformed bolt face. when you switched to a firing pin that is not tapered, you also got a firing pin that transfers all of the force of the hammer to the hole at the face of the bolt. The hole for the firing pin and the firing pin are tapered and would normally distribute the force of the hammer over a larger surface area and would not deform the face of your bolt. so it would seem that you solved a problem with a problem. you might rename this video "why not to buy a Murray's sks firing pin".

[@JPE_DRAEB]

mojogameplay Which SKS do you have? Are you saying that the Murray' firing pin cause damage? BTW do you live in Texas?

[@chrispatirot8575]

Are you using bet dan or boxer primed ammo

[@shine8357]

When you popped your primers, did you have it blow back into your face? I know a couple of other people who have had it happen it with other rifles, and it wasn't pleasant.

[@nsz85]

shine8357 I did not get blow back in my face.

[@shine8357]

nsz85 I actually found out this past Saturday! I popped one after about 75 rounds down the pipe on my Yugo.. No blow back. First I knew about it was smoke started coming out of magazine, trigger group, and the front of the dust cover. The cartridge was jammed in the receiver with the bolt closed.and I really had to rack the bolt lever to get it to eject. Dropped the rest of my ammo, took the dust cover off, bolt and bolt carrier and checked the barrel. The firing pin still rattled freely. I put one round in and it worked fine. Fired a couple more rounds, worked fine. Took it apart again, firing pin still rattled the way it is supposed to. When I got home and cleaned the rifle, the firing pin was perfectly straight with a little fouling on it. Everything else looked fine. Put the bolt back together with the Murray firing pin this time. Also had a stovepipe jam about 20 rounds in. Never had that happen before. Reason I asked about blow back is I know 1 person who has a Mosin and they had a primer pop and some of the powder blew back in their face. It stung them and they got a minor burn on the nose and cheek right under their safety glasses. I've never had it happen with any of mine.

[@chrisrhodes6210]

It's a good idea to counter sink the firing pin camber on the bolt face, because when the bullet get cambered. The rim will scrape against the sharp edge and leave brass shavings inside the firing pin camber. After a few time firing. More and more brass shavings will clog up firing pin chamber. When the hammer strikes the firing pin. The firing pin will travel all the way to the brass shaving clog and stops the firing pin travel, this is at the same time the hammer is pushing the firing pin forward. All this is happening an few thousand of a second. Some where along the shaft of the firing pin the stress is so great that it just cant handle it and brakes.

[@JeromeBill7718]

Should you countersink it first?

[@rockyriver123]

Very nice video, How many rounds do you guess that your SKS has had thru it? I have not noticed this volcano mound around my firing pin hole.

[@nsz85]

I would try just using the murray's pins without any modification yet. If you bolt face doesn't look like mine did at the beginning of this video then you are already ahead of the game haha

[@nicksalva2912]

The cratering is caused be the original tapered firing pin slamming into the tapered inner hole of the bolt pushing out the metal. Strong hammer spring is the cause, used to fire hard Berdan primers. You could use a lighter spring but only with soft commercial primed ammo, lighter spring will not work with surplus ammo, you will get light strikes and misfires.

[@josephd27]

what kind of ammunition do you use in your sks?

[@nsz85]

The firing pin breaking like that is a direct result of popped primers. I am willing to bet that your firing pin had black on it/looks charred. You have to do what I show you in the video to hopefully fix it. This is exactly the reason I did it :)

[@ciscokidkid6580]

Ya I've gone through 2 pins already. They seem to be blowing out of the bolt.

[@dantheman7624]

so now that your bolt face is flat again check your fireing pin potrusion and make sure it is not sticking out too long to make sure your pin is not piercing primers. if it is than its time for a new bolt.

[@ciscokidkid6580]

Has it been doing better for you after the mode.

[@nsz85]

Yup running like a top!

[@nsz85]

No.

[@nsz85]

Thank you very much. I appreciate the feedback!

[@JeromeBill7718]

Fine sand paper on a q tip works good in a drill to polish the hole

[@dantheman7624]

Another tip. NEVER dry fire any SKS. The hammer hitting the fireing pin is whats pushing the face of the bolt out. Your fireing pin bends also causing it to stick with in the cavity causing some slam fires. So NEVER try to drop the hammer on any SKS with an empty chamber. The SKS will always be cocked USE THE SAFETY. The fireing pin bottoming out on the bolt face from dry fireing is causing the bulge and bending the fireing pin. After you empty the mag and the bolt locks open put the safety ON.

[@joelopezjl28]

dantheman7624 pretty sure a hardened bolt isnt going to get damaged by a firing pin which is softer its caused by speedy machining

[@MinnesotaShooter1980]

Did it work?

[@louiscyfer6944]

was this volcanoing?

[@nsz85]

Awesome! I am glad I could help! Tell Murray's I sent ya :)

[@nsz85]

Lucky you then because it can create a lot of problems apparently. The round count on my rifle is not known. It's all matching, and is military surplus so who knows what it saw.

[@inspectyerbooty]

what a beautiful finesse job, and great camera work and tutorial. f@cking awesome work. i hope to find the update video to see if it fixed your primer prob :)

[@nsz85]

Wolf, Herters, Yugo surplus to name a few

[@johnlovescathyforevers6116]

Must be using aftermarket soft primer ammo....causing failure. Use steel case tula or other military surplus ammo..thats what they were made for..ive had sks for 25 yrs..no problems

[@7980flh]

Great video. Will be doing mine as soon as I get the little stone. Thank's..............

[@rugerp9045]

Getting a sks soon thanks for the info.

[@eckpeck]

Still working for you?

[@nsz85]

Yes!

[@dixoncider7256]

great close ups!

[@warrenlikesboats]

your bolt face shouldnt be like this... and if its a popped primer, its mostly likely going to go off anyways. The bolt face on my Simonov SKS is in perfect condition, but very rarely i'll experience a popped primer (in the cheap Chinese ammo i shoot) and it will go off as soon as the bolt is closed. the ammo is the problem not the gun; well unless your bolt face is messed up like this one.

[@BigGun1911]

Nice video bud keep it up!

[@nsz85]

That is correct!

[@CrudeConduct666]

Never had this problem. Just in case this video scares anyone away from the SKS.

[@bruceinoz8002]

Countersinking the striker hole in the bolt face may not be a really good idea. Firstly, how could the "condition" occur? My WAG is a LOT of dry-firing. The "pointy-end" of your basic SKS striker i more-or-less a truncated cone. Theoretically, this may provide a better gas seal. When the rifle is fired with live ammo, the flat-ish striker tip will have ignited the primer before the striker "cone" meets the matching taper int he bolt. As the primer ignites (striket drives the primer cup against the "anvil",be it Boxer or Berdan primed. This absorbs some of the energy in the striker. As the primer ignites, the brass cup tend to "move backward fron the internal pressure. It will partially drive the striker back, but not very far. The trick is to maintain a good seal whereby the primer has no "flow-points where the cup metal can start "extruding out . IF the strike tip is "undersized, or the strker hole is OVER-sized, the cup will 'flow" into the associated "gap between the striker and bolt-face.. As the rass in teh primer cup is extruding, it is also being 'work-hardened and brittle. If it develops a crack, propellant gases WILL punch through such cracks and start to "gas-cut" the tip of the striker and the bolt-face.. Higher-pressure cartridges like the 5.56 NATO will do the same thing under similar condition, but the damage will accrue faster.. The "raised" ring on your bolt face is likely what is causing primer cup failure. If you simply simply stone off the raised metal it should reduce the problem. Ammo note: "Commercial" sporting ammo is probably fitted with "domestic" primers. The cups on these are generally THINNER than genuine Mil-Spec primers as originally loaded in a bazillion rounds of Russian, Chinese, etc cartridges.. A tapered countersink is not the answer. If you are reloading, check out the availability of "Mil-Spec" primers. Start with CCI "Magnum" primers are called that because they are loaded with a "brew" that provides a bigger intensity and endurance of the "flash, to PROPERLY ignite large quantities of slow-burning powder. 7.62 x 39 is definitely NOT a "magnum" cartridge, however.. If the "issues" persist, track down an "unused" bolt. And if you are really adventurous, turn a slight radius on the edges it the striker tip to reduce "metal-fatigue in the primer cups. BUT, in your adventures, only make ONE change at a time and test it. Juggling multiple variables is a poor research technique.

[@nsz85]

You're welcome, comrade!

[@elliothuh669]

Almost, seems like you might as well at least counterbore your SKS bolts even if they aren't volcanod.

[@nsz85]

That is incorrect. You can dry fire an SKS all day long when it has a murphy's pin in it.

[@o9rgeronimo979]

Murphy's firing pin is junk. Russians did away with the spring bc it got hot and brittle, breaking and causing problems

[@nsz85]

You are very welcome :)

[@Sig_P229]

Mini 30s had the same issue

[@SUPERBEAST856]

Thanks for posting! Awesome.

[@nsz85]

Thanks for the sub!

[@nsz85]

You know...headspace.

[@nsz85]

You are welcome :)

[@dantheman7624]

Cool that is a better fireing pin.

[@oscarpuente2029]

outstanding!

[@nsz85]

Thanks :)

[@28GunsLater]

Hmm.. and I thought this was because I was running Wolf ammo!

[@AxelReyes-bl9fz]

thank you.:-)

[@scotmckay977]

You need to replace your bolt,if the firing pin is pushing metal out then you will eventually stick the firing pin and your gun will run away on full auto. I believe the bolt was not hardened properly and should be replaced. With a tapered firing pin you are flirting with disaster!

[@patrickkinney4998]

That’s not a 100% fix.

[@jamesw4445]

What else needed to do to fully fix it? I will have an SKS soon and would like to fix the fault so I can use the cheaper ammo. (I am going to buy a Murray pin). Thank you.

[@jamesw4445]

@Neito Kradavish Thank you! I did purchase a Murray's pin earlier this month. Haven't fired the SKS yet but no longer have concerns on this issue.

[@o9rgeronimo979]

​@@jamesw4445 how would you know if you haven't fired it🤔

[@darthkevin30]

Did it work?

[@nsz85]

I haven't had any issues since.