Pierced primers, help with diagnosis

[KMart]

Needs a new firing pin!
Need to check firing pin protrusion!
Needs the bolt head bushed!
Needs different primers!
Stock is probably the wrong color!
When you get thru throwing $$$$ at it, try checking the case fit in the chamber.
Factory ammo is NOT fire formed to your or anybody else's chamber.

My guess? Factory ammo too short for the chamber, (till the cases are fire formed) firing pin hits the primer, round goes BANG, case too short for the chamber, primer tries to back out of the pocket and gets "pierced, blanked or whatever you want to call it by the firing pin and EVERYBODY tells you to throw YOUR $$$$ at it trying to solve a problem that can be easily fixed with reloads that havn't had the shoulders pushed back too far to cause the same problem. Start there then get back to us.

Hornady seems to be the king when it comes to undersized factory ammo, resulting in ejector marks and blown primers. Along with that, their primer cups may be quite thin, since we do not know who and where they were made.

 

[beemanjohn]

Contact forum member @Grimstod and have your bolt bushed. He is famous for his Savage bolt work. (and other brands too) Savage bolts have way too large of a hole for the firing pin. @Grimstod does great work for a very reasonable price. You will not regret it.

 

[SKWERLZ]

I’ve done a little googling on this, but haven’t been able to get a clear direction on what my next steps should be. My 6mm ARC pierced 4 of 20 primers today and now I feel like there is an issue to fix.

Background: Gun is a factory Savage 110 Switchback in 6mm ARC. I installed a Rifle Basix trigger, but its otherwise stock.

I shot the Hornady Match ammo 108gr ELD-M for barrel break-in and to accumulate some brass. I pierced a primer in the first box and another 2 or 3 over the first 100 rounds fired.

I loaded some 103gr ELD-X and had no issues. Re-sized with Hornady dies, loaded with LeverEvolution (getting close, but below max book load) and CCI 450. No issues, but they didn’t group well.

Next I loaded some 95gr Berger VLD-H with Lever and CCI 450’s. Did the seating depth test and found it favored 0.050” jump with groups about ½”. No primer issues.

I wanted to try the 95gr Berger CH, again loaded with Lever and CCI 450’s. Has potential here, but have not revisited yet to get dialed in. No primer issues. I installed the Rifle Basix trigger right before testing these and was still settling in with the vast improvement over the factory trigger.

Today, I shot 20 loads with the 87gr V-Max loaded with Lever and CCI 400’s. Good potential with groups from 0.650 – 0.890” but I pierced 4 of 20 primers. I also shot 6 factory rounds today, for what it’s worth, no pierced primers.

Why I switched to the CCI 400 with these last rounds (87gr V-Max) I can’t remember. I intend to shoot 450’s with this round, so maybe my issue with correct itself when I use 450’s for my next batch… or maybe not. It got me thinking about the 3 or 4 that were pierced in factory rounds. Is there an issue with the bolt or firing pin that needs to be addressed?

To revisit the primer issues, it was 3 or 4 pierced factory primers in the first 100 rounds. None in the next 100 rounds. Then today 4 of 20 in handloads. Rifle has 230 rounds down it as of today. None of my loads are above max or show signs of pressure outside of the pierced primers, if that is related to pressure in this situation.

I guess what I’m looking for here is some guidance on whether to take it in to have it looked over or just load another batch with 450’s to test. I don’t mind doing the testing, but I’d hate to find out the hard way I should have stopped sooner and it seems like the googling is hinting at a firing pin issue.

#400 is an excellent primer but cup is thin and it doesn’t like pressure.
Especially in a sloppy bolt like savage is famous for.

 

[jmkasza]

Needs a new firing pin!
Need to check firing pin protrusion!
Needs the bolt head bushed!
Needs different primers!
Stock is probably the wrong color!
When you get thru throwing $$$$ at it, try checking the case fit in the chamber.
Factory ammo is NOT fire formed to your or anybody else's chamber.

My guess? Factory ammo too short for the chamber, (till the cases are fire formed) firing pin hits the primer, round goes BANG, case too short for the chamber, primer tries to back out of the pocket and gets "pierced, blanked or whatever you want to call it by the firing pin and EVERYBODY tells you to throw YOUR $$$$ at it trying to solve a problem that can be easily fixed with reloads that havn't had the shoulders pushed back too far to cause the same problem. Start there then get back to us.

And I'll add, out of my 5+ Savage rifles (I've lost count) the only issue with pierced/blanked primers was from the cases being too short, getting the "pierced thang" because the cases were to short.

This is good info, the kind of thought process I needed. Perhaps I wasn't clear enough that my goal is to eliminate as many variables as I can before throwing money at it. With the feedback so far I am committed to using 450's and confirmed the fp protrusion is within spec. Neither of those things cost me anything. I hadn't thought too much about the cases being too short for the chamber, but I can do some measurements and see if that brings forth a concern.

 

[esromvre1]

Do not use a 6 1/2
It's for a 30 carbine

Had the same problem for me it was spring tension on the pin

 

[Ned Ludd]

CCI 450s worked with no issues. CCI 400s had 4/20 pierced. The simple math here says don't use the CCI 400s; they have a thinner cup.

 

[jmkasza]

CCI 450s worked with no issues. CCI 400s had 4/20 pierced. The simple math here says don't use the CCI 400s; they have a thinner cup.

It was the pierced primers on the factory ammo that got me thinking there could be more to it than just a primer change on the last batch.

 

[tommeboy]

Savage bolt heads are dished and can add to the problems others have mentioned. Get the bolt head bushed or order a PTG bolt head. But the main problem is the wrong primers.

 

[Kracken McGraw]

There are lots of things that make me wonder why I took a ride on the Savage train.

 

[mudduck]

Ok

It was the pierced primers on the factory ammo that got me thinking there could be more to it than just a primer change on the last batch.

i think this is a savage problem. Buddy has the same rifle and had same issue with factory ammo also.

 

[Ned Ludd]

It was the pierced primers on the factory ammo that got me thinking there could be more to it than just a primer change on the last batch.

Yes, I understand that. But I'm guessing you do not know with any certainty the identity of those particular primers used in the commercial ammunition. What you do know with certainty is that CCI 450s did not exhibit piercing and CCI 400s did. CCI 400s are known to have such problems and they also have a thinner cup. As shown in the table below from a Bulletin article by James Calhoon,


(https://www.accurateshooter.com/technical-articles/primers-and-pressure-analysis/)

there are other primers that are known to have relatively thin cups including Fed 200s and Rem 61/2. Any one of these relatively thin cup primers might have been used in the commercial ammunition that exhibited piercing, but your handload results demonstrated with certainty that the CCI 450s, which have a thicker cup, did not fail. Sometimes you just have to go with what is certain, and for now that is looking like using the CCI 450s exclusively.

In the event you were to start getting cup failures with the CCI 450s, it might be time to consider more involved action such as swapping out the firing pin and/or getting the bolt face bushed. I've had a couple friends in the past that experienced the exact same issue as you when using CCI 400s. They switched to CCI 450s and their problem went away, never to return. Hopefully that will be the result for you. Best of luck with it.

 

[Turpentine]

On Remingtons, it's almost always that the hole is too big for the pin and the brass flows around it.

Just had to replace my DPMS bolt because of this!
OP are your primers cratering and flowing bad or is the pin just blowing through the cup? You might try CCI 450s or 41s. Or Fed 205ARM.
I just did an update on the forum on this bit since DPMS is defunct I went with an Adams Arms bolt and firing pin. I had to use my old cam pin. No cratering now.
.

 

[gunsandgunsmithing]

On Remingtons, it's almost always that the hole is too big for the pin and the brass flows around it.

Just had to replace my DPMS bolt because of this!
OP are your primers cratering and flowing bad or is the pin just blowing through the cup? You might try CCI 450s or 41s. Or Fed 205ARM.
.

Yes...very common on Remingtons as well as some others. IME, pins don't blow through primers and in that context, you can never have excessive pin protrusion. The primer is what stops the pin, no matter how long it is. Of course if it blows out, not much else is there to stop the pin. If you've ever noticed, when you have fully blanked primers, you very likely also have to remove that little disc of brass from inside the bolt body or you'll have other issues as well. That pressure that blows the disc into the bolt is exactly what breaks some Jewell triggers because the pressure blows the pin backward, possibly all the way to coil bind and when the pin flies back forward, ..that's when it breaks the trigger. Just FWIW. There's a lot of confusion on this subject and trying to do my part to explain what happens and why, as best I can is all.

 

[jmkasza]

On Remingtons, it's almost always that the hole is too big for the pin and the brass flows around it.

Just had to replace my DPMS bolt because of this!
OP are your primers cratering and flowing bad or is the pin just blowing through the cup? You might try CCI 450s or 41s. Or Fed 205ARM.
I just did an update on the forum on this bit since DPMS is defunct I went with an Adams Arms bolt and firing pin. I had to use my old cam pin. No cratering now.
.

No cratering or flowing. The primer looks "normal" other than the dark spot where the pin punctured the cup.

 

[jmkasza]

Yes...very common on Remingtons as well as some others. IME, pins don't blow through primers and in that context, you can never have excessive pin protrusion. The primer is what stops the pin, no matter how long it is. Of course if it blows out, not much else is there to stop the pin. If you've ever noticed, when you have fully blanked primers, you very likely also have to remove that little disc of brass from inside the bolt body or you'll have other issues as well. That pressure that blows the disc into the bolt is exactly what breaks some Jewell triggers because the pressure blows the pin backward, possibly all the way to coil bind and when the pin flies back forward, ..that's when it breaks the trigger. Just FWIW. There's a lot of confusion on this subject and trying to do my part to explain what happens and why, as best I can is all.

I removed a little bit of brass residue from inside the bolt body, but it very minimal. A tiny amount of dust.

 

[Turpentine]

Definitly interesting. I’m glad to get the information.
My son just bought a converted SMLE that went from 303 to 410 When the Brits didn’t trust the Indian guard with rifles or something like that anyway. It’s an interest piece. Tried a couple different pins and lengths with different protrusion. It would light strike one time and then blow through the cup Just like you drilled the hole. Definitely a headspace issue among other things but it’s not a piece to put money into. I wasn’t there when he bought it and he couldn’t shoot it beforehand. You can put 5-6 cut pieces of electrical tape on the case head and still easily shut the bolt. The primers are blowing out and slamming against the bolt face. I may get it fixed for him one day. If for nothing than a conversation piece.
I have a Citori that would pierce primers. Then the firing pin tips would erode and things would really go south. I Finally put a set of J and P firing pins, springs, and hammer springs a in it and had no more issues.

 

[butchlambert]

Headspace and firing pin to firing pin hole clearance.

 

[Old Navy]

Needs a new firing pin!
Firing pin needs to be replaced!
Need to check firing pin protrusion!
Firing pin tip defective!
Needs the bolt head bushed!
Needs different primers!
Stock is probably the wrong color!
When you get thru throwing $$$$ at it, try checking the case fit in the chamber.
Factory ammo (makes no difference who loaded it) is NOT fire formed to your or anybody else's chamber.

My guess? Factory ammo too short for the chamber, (till the cases are fire formed) firing pin hits the primer, round goes BANG, case too short for the chamber, primer tries to back out of the pocket and gets "pierced, blanked or whatever you want to call it by the firing pin and EVERYBODY tells you to throw YOUR $$$$ at it trying to solve a problem that can be easily fixed with reloads that havn't had the shoulders pushed back too far to cause the same problem. Start there then get back to us.

And I'll add, out of my 5+ Savage rifles (I've lost count) the only issue with pierced/blanked primers was from the cases being too short, getting the "pierced thang" because the cases were to short.

Lucky man.

 

[Old Navy]

Before and after having the bolt bushed and pin turned down.