Bad primers?

Seabee · Sep 3, 2021

Today at the range I was testing loads in 7x57AI and 284 Win. I was using CCI 250, lot number A21V32 primers. One case in each 3 shot group had a pierced primer. I have fired 40 rounds with these earlier in the week with hotter loads in hotter conditions. These loads were slightly lowered and speeds of all rounds were similar to each other so no pressure spikes. I fired the same lot in a 257AI with no issues. Has anyone had similar issues? I've emailed CCI.

Usmc1968 · Sep 3, 2021

where did you find primers?

pre64hunter · Sep 3, 2021

Doesn't seem right. Better check the end of your firing pin though, the pierced primers will etch it and erode the tip and sometimes the bolt face. I've had pierced primers but usually the primers were flattened and sometimes pierced on the edge.
I had a box of 270Win factory Remington Core-Locs once and they shot fine except the last round in the box I shot pierced the primer. It etched the bolt face leaving a tiny pit, insult to injury, it was somebody else's new gun. Never figured that one out either.
Let us know if CCI says anything.

Doco Overboard · Sep 3, 2021

Is a magnum primer necessary for igniting the type powder your using or are you using them out of necessity?
7x57 isnt really a long case nor is the .284
Especially if load density is not 100% or compressed.
You mentioned you were testing the ammo.

Seabee · Sep 3, 2021

Doco, i was testing to see if mag primers improved the accuracy. It did.
Ive used about 500 from that brick without an issue till now.

Doco Overboard · Sep 4, 2021

I would closely examine the tip of the firing pin as mentioned above, reduce the charge an appropriate amount to eliminate pierced primers.
Because a high order of ignition depends on nearly all the grains of powder igniting simultaneously, it has been found burning characteristics can behave differently when over ignition occurs in shorter cases.
Powder type, grain size and composition have influence on the chemical reaction/internal ballistics on the same.
It has been noted that in most cases ignition becomes erratic, pressure spikes become prevalent and accuracy usually becomes degraded.

Because you have noted increased accuracy the problems described above may not be the case. The pierced simmers you exhibited very well could be from soft primer cups supplied by the manufacturer and then becoming more obvious in unison with loads developed in an improved case.

At the very least I would be closely looking at physical damage occurring to the firing pin, firing pin port and bolt face. Even if there is nothing wrong with the primer cups, a rough firing pin tip can tear or pierce a primer in a normal pressure condition. I would suspect continued firing with a pierced primer would only become worse and with higher frequency with continued firing.

The other thing is, only you can decide if the increase in accuracy you achieved can be maintained through through different lots of cartridge components vs the potential damage/ safety concerns that are associated with experiencing pierced primers in your rifle.

Primers are the most dangerous individual component of any cartridge. Most if not all loading manuals recommend reducing the charge or working back up whenever an over pressure condition occurs or different component lots are used.

Uncle Duke · Sep 4, 2021

Op has pierced primers in TWO SEPARATE rifles? That would SEEM to suggest that this isn't a firing pin issue.

While a defective batch of primers is possible, I'd be looking hard at the loads themselves. Especially if they were originally created using standard primers, as the later introduction of magnum primers can create significant differences in pressure.

HOW significant? Short of a lab, there's no way of knowing definitively. I've seen reports of differences of 10% or more. Thing is, as opposed to what? It's hard to say what percentage of increase you have, because it's only YOUR set of load and rifle variables that matters. But be that as it may, those pierced primers are most certainly a message that something somewhere isn't right.

Seabee · Sep 4, 2021

Finished checking firing pins. Savage was fine. Ruger was etched. Its been repaired and polished. No damage to the bolt faces. I calibrated grt to my load and rifle and pressure comes up between 54,000 and 55,000 for both rifles. Its just a simulation but its fairly accurate. At 10% increase due to mag primers im still not over 60,000 and that isnt enough to cause this issue plus the fact i had fired much hotter loads earlier without incident leads me toward faulty primer cups. Just really odd that it happened on the last round in 2 rifles. Im gonna trash that tray and open a new one and if it happens again then the whole lot goes. Thanks for the help and advice.

outrider58 · Sep 4, 2021

OP, are these 'post COVID' primers. It wouldn't surprise me if, in the haste to keep up with demands, quality control may have slipped a bit?

Seabee · Sep 4, 2021

outrider58 said:
OP, are these 'post COVID' primers. It wouldn't surprise me if, in the haste to keep up with demands, quality control may have slipped a bit?

I thought the same thing but these are at least 3 yrs old. Ive trashed the sleeve they came from in case it was a primer issue. I disassembled both bolts to check the firing pins. The savage was like new and the ruger was etched. I refinished it and it’s like new. I also went back to standard primers. Next week ill zero them for hunting and done…..i hope. Thanks

pre64hunter · Sep 4, 2021

Maybe temperature?

Seabee said:
I thought the same thing but these are at least 3 yrs old. Ive trashed the sleeve they came from in case it was a primer issue. I disassembled both bolts to check the firing pins. The savage was like new and the ruger was etched. I refinished it and it’s like new. I also went back to standard primers. Next week ill zero them for hunting and done…..i hope. Thanks

Seems very odd, two different rifles and calibers, the pressure looks low judging by the spent primers. The first half of the primers were fine now this? Could it have been some external factor like the temperature outside being too hot or were they in a hot car or truck too long, oil in the barrel or chamber, rifles sitting in the sun between group, case lube?

JBoshoven · Sep 4, 2021

I had a primer issue a couple years ago. It was with some Winchester large rifle primers. The last sleeve of 100 out of a 1000 primer brick were bad. I used most of the primers to load for my .270 Win and a .243 Rem. Never had and issue. Then I started using them to develop a load for a new 6.5 CM. Again, until I got to that last sleeve no issues. I settled on a middle of the road load and continued getting to know the gun. When I got to the last sleeve, I had three primers pierce on the edge of the cup. They etched the bolt face and burned the edge off tbe extracted plunger. The plunger was damaged enough that I had to replace it. I was chronographing the loads (working on developing temperature - velocity curves) and the velocities were as expected. I sent an email to Winchester with the lot number. Have not heard back from them. As the load is not near the limits, and the velocities were as expected, I marked the primers as bad. I started another brick with a different lot number and have not had a pierced primer since. I guess all that to say, no issues with most of the 1000 in a brick with the same lot number, but at least three bad ones in the last sleeve of 100.

Jack

Magnumite · Sep 5, 2021

I had an M28 Smith 357 Magnum revolver with the tiniest little anomoly onthe firing pintio. It pierced primers every once in a while.

Seabee · Sep 5, 2021

pre64hunter said:
Seems very odd, two different rifles and calibers, the pressure looks low judging by the spent primers. The first half of the primers were fine now this? Could it have been some external factor like the temperature outside being too hot or were they in a hot car or truck too long, oil in the barrel or chamber, rifles sitting in the sun between group, case lube?

They were in the house for about 3 yrs. At the range they were in the shade in my vehicle or on the bench in the shade. Pressure were normal, not to hot either. The other rounds fired were perfect. I may go back to federal when they are available. I left cci years ago over misfires that i never had with federal. The only reasons i came back to cci was i heard the fixed the misfire issues and federals could not be found. Im sure its a primer issue. I tossed the last 40 in the sleeve into the drink.

John from MD · Sep 5, 2021

There were no pressure signs and I have shot etched pins that don't make holes in the primers. I suspect some pistol cups or material got caught up in the mix.

Magnumite · Sep 5, 2021

perhaps. And I regret selling that revolver. It was highly accurate and consistent. Oh well…live and learn..again…

Bad primers?

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