Primer issues

[pills]

I have had some primers penetrated by the fireing pin, I am wondering if you guys have any ideas as too why? Weak primers used? The ammo is factory Hornady Superformance Varmint in .223. It has happened to about 30% of these rounds.
The gun is an AR with a 223 Wylde chamber. I also fired some cheap bulk Fed and some Black Hills stuff with no issues. I have not fired reloads in this gun yet.

 

[Codeman]

Looks like a hot load to me

 

[CJ6]

I'd call Hornady, also have the rifle checked by a GOOD Smith. Save any ammo you have left of this lot/box/s

 

[KMart]

I have never fired any Hornady factory ammo. With that being said, some of my friends have. I have looked at the fired cases and noticed that the primers were very flat, and to me, that indicated that the ammo was fairly close to max. Maybe your chamber confirguration and this ammo is not compatable.
The ammo I looked at was 168 Amax Match 308.

 

[KevinThomas]

Pills,

You need to replace your firing pin. Not saying that was the cause of the first piercing, but once you've popped one primer, it will usually result in an etched tip on the pin, which will cause other ruptures in turn. Always pays to keep a spare pin on hand, for just such occurances.

Hard to say what might have caused the initial piercing, but with factory ammo, I doubt it was pressure. At any rate, check out the tip of that pin unxer magnification, and see if you don't have some pitting or etching. Swap it out for a new one, and see if that doesn't take care of the problem.

 

[tenring]

Last year, my Dasher blew a primer. I continued shooting. Week later, it blew a second primer, and after that the bolt would not cock. I had to replace the entire trigger, it separated the sear from the engagment. At the same time, my gunsmith made the firing pin tip a little flatter, and this ended the blanking.

 

[drumcorpschamp]

You should read this.

http://www.hornady.com/ammunition/superformance-in-gas-operated-firearms

Jerry

 

[KevinThomas]

Jerry,

OP made no mention of barrel length, but the question of port pressure is a good one. Certainly could account for what he's seen. Good post!

 

[drumcorpschamp]

Jerry,

OP made no mention of barrel length, but the question of port pressure is a good one. Certainly could account for what he's seen. Good post!

Thanks Kevin. The descriptions of the visual symptoms in the Hornady document were too close to what I saw of the picture attached by the O.P. for me to ignore it. Glad it was attached in the first post!

pills......tell us about your gun.......make, model, barrel length, gas configuration, etc., etc.?

Jerry

 

[big bad bill]

one should check the firing pin protrusion from the bolt bead to insure it does not exceed approximately 0.060 with the pin in the fired position.
Bill

 

[FroggyOne2]

Wasn't there some of the same issues with some 6.5 Creedmoor ammo that Hornady had made when it first come out?

 

[lloydx2]

Several years ago I unintentionally overgas ed a 20" AR rifle length gas Was running 90 gr matchkings VVn550 I knew I was heading down that road. I ran a heavier carrier and buffer. Even ended up putting drilled set screws threaded into the gas tube to try and slow it down. Service rifle rules limited me to what I could do externally. The first signs I saw Extractor grove smearing (case wipes) Bent case rims Flat primers. But I never saw any Primer cratering or pinholeing. Usually the first sign of over gassing is case wipes. I would definitely check pin protrusion just for grins. Let us know whats up

 

[Scott Harris]

Assuming you have previously working rifle, the ammo is simply too hot: stop using it. You probably need to replace the firing pin at this point, as Kevin stated.

 

[markm87]

Kevin Thomas is correct as usual. Also, there's a firing pin protrusion guage. It wouldn't hurt to check that you're not getting excessive pin protrusion.

 

[pills]

sorry for the delay in getting back to you guys, I was away. The barrel is a Lothwer-Walther .223 wylde 16" medium length gas tube. Upper has a Troy receiver and lower is Armalight. I dont have a guage to measure firing pin but will see if I can get ahold of one. My only other input is that it has only happened with the Hornady Superformance, all other ammo before and after had no issues.

 

[pills]

Just read the attached link to Hornady Superformance. That sounds like exactally what is happening here. I will have to stop using that ammo in this gun I guess.

 

[jraney]

i had this happen to me today with 3 of my reloads. i did not think i was to hot but i guess i could have been, but my gun failed to fire 2 rounds before i noticed the problem. it was like the spring got weak and did not hit the primer hard enough. my gun is a bolt action savage and this is the first time this has happened. do i need to change the pin as mentioned before?

 

[fguffey]

I would replace the firing pin spring, when the pressure exceeds the ability of the spring to maintain firing pin contact the firing pin is pushed back allowing the pressure inside of the primer to punch a hole from the inside out.
To review, the firing pin crushes/dents the primer, the primer ignites, then the pressure inside the primer forces the primer to conform to the firing pin, if the firing pin spring is weak the pressure pushes the firing pin back.
The Hornady ammo with the punched primers indicate the firing pin spring is marginal, a stronger firing pin could prevent punched primers.

It is a .7854 thing.

F. Guffey

 

[Randfal]

Let's go back to the original description. There are no issues with several other brands of ammo. The Hornady ammo is too hot for your rifle/chamber/combination. Nothing wrong with your AR, ammo is just too hot for conditions. Solution: don't shoot that stuff. Try something else. For grins; chill a few rounds on ice and shot them first in your cold barrel. Then shoot some warmed up loads in your barrel when it's hot. I'd wager you don't blow the cold rounds. That ammo is probably right on the edge of too hot.

 

[fguffey]

“That ammo is probably right on the edge of too hot”

And for more grins, look at the first post and the picture, look closely, examine the the primers, my opinion, NOT GOOD! Especially the one on the bottom left, it has a crater as in a dent in the middle with a high wall around it, meaning? Pre-existing condition, again, I would replace the firing pin spring, as to pre-existing conditions? Any time the primer conforms to the firing pin there is a chance the primer will flow into the hole around the firing pin.

A fired primer with a small dent is the first warning a shooter gets when the spring is weak.

F. Guffey