Primers for loading 7.62x39 to prevent slamfires?

CCI #34's.

I’ve used nothing but CCI 200 for my WASR and haven’t had any issues.

just don’t forget one of the golden rules and keep it pointed in a safe direction when making it ready

I loaded for a vz-58 and never had any slamfire issues with any LRP primers I used.

For a Russian SKS CCI primers have worked well for me, either small or large I have brass for both. But with a floating firing pin it is a concern, as with the Makarov PM. Wish Russian primers were available in my area.

For slam fires, is best to fix the problem @ the source. Remove the firing pin & inspect pin for burrs & mill marks. Also inspect the pin bore in the bolt. AKs often have rough machining that causes occasional binding of these parts. Krockus cloth or files will take care of it. Very dirty pin bores get stuck firing pins also.

Another issue causing slam fires is single loading one cartridge by hand into the chamber, then dropping the bolt full on it without the friction of stripping and feeding the cartridge. That has caused slam fires in alternative cartridge guns like an AR15 chambered for .458 SOCOM using soft bolt gun primers. Self loading actions are better off safety wise using harder military primers - which were specified in the first place for a self loading or automatic action with the bolt hammering away during the loading process.

Google Federal primers in .223 Remington for AR actions.
Check the history behind redesign of the AR firing pin to make it lighter than the original M16 firing pin to help prevent slamfire.

Given the energetic feeding cycle of the AK, I stick to ammo loaded to military standards (and single feed from a magazine).

What about using a primer pocket uniformer on your brass before loading?

This way you can get the primers to sit about 0.005" or so deeper in the pocket. That should help to keep the firing pin from coming into contact with the primer when the bolt goes forward.

If I were worried about it CCI #34 Large Rifle or CCI #41 Small Rifle.

Mk-211 said:

What about using a primer pocket uniformer on your brass before loading?

This way you can get the primers to sit about 0.005" or so deeper in the pocket. That should help to keep the firing pin from coming into contact with the primer when the bolt goes forward.

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I don't think I would run with that thinking. My reasoning is this. Normal firing pin protrusion, including free floating firing pins, is generally between 0.050" to 0.60" with some getting close to 0.70'. Normal primer sensitivity is about 6.0 Lbs. of force on a center fire cartridge. With more free travel distance a free floating firing pin will develop more inertia force and while I doubt the primer seated to 0.003" forward of breech face and 0.005" breach face will matter technically the firing pin traveling further will develop more force. The minimum protrusion I have seen and measured was about 0.055" so a few thousandths of primer depth in the primer pocket I just don't see mattering much as to a possible slam fire. I do favor uniform primer pockets when building high power match quality ammunition since we stride for everything being as uniform as we can get. .

The CCI #34 and #41 primers reduce sensitivity by changing the anvil angle in the primer cup. From our friends at CCI "Mil. Spec. primer, thick cup, magnum primer charge, angle of anvil change".

Other manufacturers also make less sensitive primers but my experiences are with the CCI primers.

Ron

That's why we ask questions, I know that there's more knowledgeable people out there then me! I know someone will have the better answer to the problem.

That or we can all agree that a combination of ideas will work the best for whatever issue someone needs an answer to.

I wish I could remember where I read it, but as far as I know, the larger the packaging for the primers the more sensitive they are.
Look at the difference between a sleeve of CCI and Federal for example.

I believe there is a law somewhere that states what the minimum packaging is for explosives, and the easier it is to set off, the larger and more protective the packaging.
I just picked up 1K of Fed SRP and the packaging is easily 2 or more times larger than the #34, #41, or CCI standard I have.

How much more sensitive in use, I've never seen any decisive answer.

Oh, and PS... According to the MSDS sheets the compounds are all different between all of the brands. CCI #41 & #34 are also different than the standard CCI primer.

When I loaded for 7.62x39, was for a PTR-32 and multiple AK's. I had both small primer, and large primer brass, from a couple of different makers that I got over the years. I used either large rifle magnum, or small rifle magnum, or whatever large/small rifle Tula/Wolf/Murom primers I had laying around. The large primer brass seemed to stretch the primer pocket pretty quick, after only a few loadings, so I preferred the small primer brass for longevity. No real performance difference between them that I recall, though the small primer brass was pretty hard to find IIRC. For the large primer brass, the cheap russian made primers worked the best, and you could get 2 or 3 more loadings out of them before the pocket stretched to much to use compared to the US made primers.

just buy cheap Russian Ak ammo and you will be fine

merlynski said:

I am considering that, but it is something else to buy, and another step in the process. The possible slamfires happened on my sons IO Inc rifle, and I did not witness them, and he does not remember what ammo he was using, except it was not reloads. I have yet to load my first round of 7.62x39, though I have all the components except, possibly, the right primers. I do need some more brass . . . all I have now is 100 very expensive new Lapua cases.

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Primer pocket uniformers are - in my humble opinion - and essential bit of kit for any handloader. They're pretty cheap these days and small enough to store with your square-tip screwdrivers. I like the RCBS primer pocket kit and Lyman uniformers but, they're all pretty much the same so buy what's on sale.

CCI # 41 works for me

CCI #41, for that 1/4" MOA brass on a 5"MOA rifle...I have saved brass to try reloading for that cartridge Just never bought the dies. sounds like fun.

Pottimus said:

CCI #41, for that 1/4" MOA brass on a 5"MOA rifle...I have saved brass to try reloading for that cartridge Just never bought the dies. sounds like fun.

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I gave my dies away years ago. I likely still have a few thousand rounds of the Chinese stuff and some brass cased. The irony is I only have one rifle, an early SKS, that shoots the stuff and haven't fired that rifle in maybe 15 years. Go figure. Heck, don't even know if I have any .311 bullets either.

Ron

Since the 7.62X39mm brass uses a large rifle primer and you are concerned with slam fires I also suggest using CCI#34 primers. If they are unavailable or too expensive you can use CCI-250 LRM primers. I have used Winchester WLR 8 1/2 primers in a pinch without incident but maybe I got lucky. A magnum rifle primer would be safer IMO. Some reloaders disagree. I use CCI #34 and CCI#41 primers in anything loaded for a semi-auto rifle just to be sure.

I'm just telling you what I do, not what to do. You will have to decide for yourself.

The topic of primers seems to always be in discussion, just recently on Discord reloading group I am in, here is direct quote from an overseas member.

"I have contacted SB and they told me difference standard and magnum is only in thickness of the primer bottom. Magnum is more thick then standard. I had never issue with SB and used in 300m setup with 308W."

Russian isn't going to be "harder to find." As the import certifications age, they will not be renewed, and the intent of the policy is to eliminate it from the American market completely.

This will be a slow fade over time and unless the administration changes quickly there will be long term affects. Most Russian will disappear from the market on a long enough timeline. There will be some impact on NATO cartridges, too - Tula/Wolf in 5.56 or 9mm for example, altho in one thread on the subject someone took the effort to see if it was something actually stocked at their LGS. Unfortunately, now is not a good time to verify that when entire calibers are sold out.

They snuck this one in on us and it's eventually going to hurt. No idea if Starline can supply the demand that may eventually be asked of them in new brass cases. I expect some to make reloading steel a common habit. Outdoor public ranges may well be much cleaner just because of that.

M-14 said:

The topic of primers seems to always be in discussion, just recently on Discord reloading group I am in, here is direct quote from an overseas member.

"I have contacted SB and they told me difference standard and magnum is only in thickness of the primer bottom. Magnum is more thick then standard. I had never issue with SB and used in 300m setup with 308W."

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S&B currently only manufactures a single LR primer. There is no magnum flavor. They only offer Small Pistol and Small Pistol Magnum, Large Pistol, Small Rifle and Large Rifle, the only magnum primers offered are in Small Pistol.

As to the availability all of their current primer production is going into loaded ammunition.

When wanting information on loading components just shoot an email or phone call to the manufacturer, including S&B. The following is an excerpt from a S&B email and applies to Boxer type primers:
We are currently putting all primer production into loaded ammunition at the factory and do not anticipate any available primer components for this year. If the primer production out paces our loading facilities we will hopefully have primers as a component in the future.

https://www.sellierbellot.us/products/primers/

Above is a link to our primer page on the website. We do list Small Pistol Magnum primers on our website but do not offer other magnum primers commercially at this time.

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Also from the S&B Website:

WHILE MAGTECH BRAND PRIMERS HAVE NOT BEEN IMPORTED AND OFFERED FOR SALE THROUGH AUTHORIZED CHANNELS FOR SEVERAL YEARS, THERE ARE STILL SUBSTANTIAL QUANTITIES REMAINING IN RELOADER’S INVENTORIES. IT HAS RECENTLY COME TO OUR ATTENTION THAT SOME RELOADERS ARE SUGGESTING IT IS ACCEPTABLE TO USE PRIMERS WITH CALIBERS THAT ARE NOT TECHNICALLY COMPATIBLE, E.G., 9MM LUGER/9X19/9MM PARABELLUM WITH SMALL PISTOL MAGNUM OR SMALL RIFLE PRIMERS. THESE COMBINATIONS CAN PRODUCE UNRELIABLE AND/OR UNSAFE CONDITIONS. WE STRONGLY SUGGEST THAT DATA FROM AN ACCEPTED INDUSTRY SOURCE (HODGDON, NOSLER, HORNADY, SIERRA, CCI ETC) BE FOLLOWED PRECISELY WHEN ENGAGED IN ANY RELOADING ACTIVITY.

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If loading 7.62 x 39 M43 and you can find CCI #41 primers I would run with that.

Ron

Mk-211 said:

What about using a primer pocket uniformer on your brass before loading?

This way you can get the primers to sit about 0.005" or so deeper in the pocket. That should help to keep the firing pin from coming into contact with the primer when the bolt goes forward.

Click to expand...

I saw that idea floating around on a M14 forum, and it is bogus as can be. If the firing pin can rebound off the primer, than its seating depth will not prevent ignition, if the primer is sensitive enough.

Primer sensitivity is what prevented this primer from going bang!



Now, if the pocket is reamed so deep, than misfires can happen, as happened to me:



I snapped and snapped these rounds at a match in my M70, and while the primer dented, it no go boom bang. And it was due to reaming the pockets too deep. However, they all went bang during slowfire prone in my M1a!

Rifle primers should be set below the case head, I set mine from 0.0 to 0.003", but no deeper, as deeper caused problems. There is a chance that a high primer will ignite, the anvil has to be firmly set on something, and the bridge distance between anvil and cup has to be set to the proper distance. Given the combination of those two things, a high primer will go bang if hit by the bolt face. So, I do recommend reaming pockets for gas gun ammunition. But not excessively deep.

There are two primary ways to reduce slamfires. The first, is to reduce the inertia impact with a spring.

Murray's sells a spring loaded firing pin for the SKS.

The Italians installed a spring in the Garand bolt



The AR10 firing pin is heavy compared to the AR15, and removing the spring will cause slamfires



Another way to reduce firing pin inertia impact is by lightening the firing pin



A titanium firing pin will reduce the risk of a series 70 1911 firing when dropped. Titanium is lighter than steel, and Drakes found it takes more height to cause a series 70 M1911 to fire when the pistol is dropped on its muzzle.



And the last way I know of, is with a less sensitive primer. Of the American primers on the market, only CCI has made its military primers available to the public. These are the CCI #41's and CCi #34's. I heard Federal offered mil spec primers, but I have never seen one, and I don't know anyone who found them. The military primers are less sensitive by virtue of increasing the distance between anvil and cup, and per one book, altering the shape of the anvil tip. To what shape, I don't know. Primer manufacturer's don't like to change their mixtures, so I have been told that primer mix is the same between commercial primers and military primers. I do know primer cup thickness and hardness will change the sensitivity of a primer, and that CCI customer service told a caller they don't recommend bench rest primers for gas guns, because the primer cup is thinner. Maybe it is.

The idea of burying the bunny deeper in its hole, will not prevent slamfires unless the primer is so deep, the firing pin can't set it off.

The first thing to do, is clean out the firing pin channel, so there are no rat's nests, or grease/oil to gum the firing pin in a forward position. Then, use the least sensitive primer you can find, which are the CCI mil spec primer.

Always feed the weapon from the magazine, don't drop a round in the chamber, or point the muzzle at the ground, and release the bolt. That little extra speed due to gravity is why the NRA changed the standing position loading rules. Used to be you could load on the shooting stool, and if you had a Garand or M1a, you had the muzzle up, round in the magazine, and tripped the bolt. Then came AR15's, and shooters placed the muzzle on the shooting stool. Dropped a round in the chamber, and once in a while, the rifle slamfired a round through the shooting stool!

The change upset me when I shot a bolt gun. There is zero chance of a round slamfiring when the bolt is closed, and it was easier to press a round in the chamber with the rifle butt on the shooting stool. Now I have to hold the rifle up, get a round in the magazine, and close the bolt, while not sweeping the firing line.

And, never trust a weapon with a free floating firing pin to never slamfire. Primer sensitivity varies by lot, and within the lot. You can't trust the little buggers, even mil spec primers slamfire. They are on average less sensitivity, but, nothing is perfect!