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Pierced primer! Trip to the gunsmith?


MrCetrizine

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I had my first ever pierced primer.

It was in a batch of 5 times fired cases with the same, well below max charge load I've used for years in my .223.

After it happened, I removed the firing pin from my T3 bolt and to me it looks OK. It's still smooth and round on the end. The was no carbon or other residue on it.

The bolt face was clean with no marks at all.

The bullet even hit where it was supposed to.

I fired the remaining 12 rounds I had with me and had no issues.

So, do I need to get the rifle checked by a gunsmith or is this a minor thing?

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out of interest what primers ?

I would think a minor issue if it doesn't occur again

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1 hour ago, meles meles said:

Both a vindaloo and a pierced primer can cause those symptoms...

yuk yuk 🤣

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7 hours ago, MrCetirizine said:

They were CCI small rifle primers. Not the BR ones.

There's your issue. Well, that and possibly loose primer pockets as some brass in 223 I've found wont reload past 5 reloads (eg PPU) with stiff loads. You really do need to use 0.025" cup thickness primers with the chamber pressures in 223 or what happens especially with cheap brass like PPU, is the very slight case head bowing with each firing results in loose primer pockets after about 5 to 6 reloads and you get the primer blow back, with gas escape at the side and often a badly cratered or pierced primer.  Sometimes you can get away with standard CCI200 primers on fresh brass but why take the risk as getting a bolt or firing pin damaged can prove an expensive repair? One blown primer wont usually damage the firing pin or bolt face but repeated blow-throughs will, and you may not notice the slight sooty tell tale signs around the primer if it isn't pierced and only start to notice when you see pitting of the bolt face and then check your case heads closely.

You'll be fine on CCI250 or KVB223-M or Remmy 7.5 or any BR primer (loads need to be reworked up obviously).

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It was Lapua brass. I've fired approximately 16,000 rounds with this action and bolt (on barrel 3 now) with the same load and same primers and this is my first issue.

I took it to the gun shop where I got it almost 8 years ago this afternoon, they gave it the once over and declared it good but did say that if it happened again, they'd replace the firing pin free of charge just to be sure.

I'm no CCI fanboy but they are always available to me and have always worked. 

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It's possible but it looked pretty well seated after the fact and I'm typically very careful about that sort of thing. Cases are stainless tumbled after depriming so there shouldn't have been carbon in the pocket.

I've put 50 more through it this morning and no signs of a repeat. All primers nicely dented in the middle with no cratering, light strikes or odd shaped dents.

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On 6/9/2019 at 7:53 PM, VarmLR said:

There's your issue. Well, that and possibly loose primer pockets as some brass in 223 I've found wont reload past 5 reloads (eg PPU) with stiff loads. You really do need to use 0.025" cup thickness primers with the chamber pressures in 223 or what happens especially with cheap brass like PPU, is the very slight case head bowing with each firing results in loose primer pockets after about 5 to 6 reloads and you get the primer blow back, with gas escape at the side and often a badly cratered or pierced primer.  Sometimes you can get away with standard CCI200 primers on fresh brass but why take the risk as getting a bolt or firing pin damaged can prove an expensive repair? One blown primer wont usually damage the firing pin or bolt face but repeated blow-throughs will, and you may not notice the slight sooty tell tale signs around the primer if it isn't pierced and only start to notice when you see pitting of the bolt face and then check your case heads closely.

You'll be fine on CCI250 or KVB223-M or Remmy 7.5 or any BR primer (loads need to be reworked up obviously).

a simpler view would be to avoid over pressurising your components

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43 minutes ago, Chanonry said:

a simpler view would be to avoid over pressurising your components

Agreed..........I've noticed a tendency in discussions on reloading to imply that "faster is better"..................comments like "back off half a grain when the bolt gets too stiff to open", or "when you notice a shiny patch on the case head", and those above about pierced primers. This gives the wrong message to those starting to reload.

The whole point of rifle shooting is to try and get a decent group at whatever distance you shoot at, not to fill your chrony display with 9's (and possibly ending up with brass fillings, or wearing bits of your bolt and receiver).

Pete

 

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To illustrate my point, here's a practice card I shot on Stckledown at 1000yds (electronic, F-class scoring) a while back with a 6BR. This was on a reasonably calm day (for Stickledown), and a modest load producing an MV of 880m/s with 105gn Scenar bullets and standard KVB-223 primers, well within safe pressure limit. 7 out of 10 shots look like they're within 1 MOA.

I could have pumped it up to find another node, but why? I'm happy with this result from a barrel that looks like been round the galaxy a couple of times, fired off a home made bipod.

Pete

Stix .jpg

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Its good of the shop to offer replacement pin after soo long a purchase . Kudos 

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2 hours ago, gunner said:

Its good of the shop to offer replacement pin after soo long a purchase . Kudos 

Yeah, they are very loyal to loyal customers. I've spent thousands on guns and paraphernalia over the years and typically get a few quid knocked off on every visit. I once went in there with a broken slide stop on a GSG 1911 and was just handed a new one for free. I didn't even get the gun there. 

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On 6/12/2019 at 8:14 AM, Chanonry said:

a simpler view would be to avoid over pressurising your components

Or to use the correct primer to start with.  I am not and have NOT mentioned anything about loading over-pressure components so bat that one firmly back into your court.  I stand by my comments 😉

I happen to agree though that there is a tendency for following fashionable high speed loadings.  That though clearly isn't the case here.  Accuracy nodes can be found a reasonable way under max safe pressures (or at least there's usually an accuracy node at more moderate pressures). 

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On 6/12/2019 at 11:41 AM, MrCetirizine said:

This was nowhere near maximum load. It was 23.5gr N140 with a 77gr SMK 40thou off the lands. I can run 24.7gr with no pressure signs (usually) but as stated, it's not worth pushing faster when 23.5gr works at the distances I shoot.

Just so...it doesn't stop some jumping to conclusions though  😉

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On 6/9/2019 at 7:53 PM, VarmLR said:

 found wont reload past 5 reloads (eg PPU) with stiff loads.

what happens especially with cheap brass like PPU, is the very slight case head bowing with each firing results in loose primer pockets after about 5 to 6 reloads and you get the primer blow back, with gas escape at the side and often a badly cratered or pierced primer. 

"stiff loads" implies an acknowledgement on your part that you are operating at high pressures? Real world observation, never mind the book.

If you are getting plastic deformation of the case then by definition you are over stressing the brass.

You can read manuals and Quickload output all you want for your pressures, but if your load is resulting in plastic deformation of the brass then your load is over pressure for your COMPONENTS irrespective of standard SAMMI pressure limits.

There is a reason people buy decent brass.

Not much of a jump and pretty simple really.

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  • 5 weeks later...

This has nothing to do with the OP's question as he clearly is not shooting high pressure loads.  You assume far too much.  My loads were not at all "high pressure" as in close to or over max SAAMI either and yes, I know the value of decent brass.  My Sako and Lapua brass are easily into double figure loadings but PPU is just not as durable.  You can stipulate that any deformation is pressure related and you don't have to be a genius to come to that conclusion, but loading comparative loads in various types of brass will always yield some that is more claimable and less able to obtain anything like the number of repeat loadings of others.  I detect a personal barb in your comments which is completely unnecessary, and if that was your intention, then it has no place on this thread.  

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