Pierced primers on factory ammo??!?!

[Ozshot]

So I went to work up a new load when I changed over guns the other day,
I changed scope between guns too so I had to dial gun in close again before I could work up an accuracy load. I had 6 Hornady 60gn TAP bullets left (223)
That I thought I’d use to get it close on paper before I started working the load up. I punctured 4 of the 6 primers!. I had to work load up anyway as I needed gun for work that night and barrel is shot on other gun. Worked up a hot but accurate fireforming load of federal primers 27.4gn ADI 8208 with 52gn Speer HP halfway up neck and no pressure signs or blown primer. Have had 300+ rounds through since and not a problem….. any thoughts?? How can a factory round do that?

 

[JSH]

Check firing pin protrusion, maybe on the max side.

 

[243winxb]

Your velocity compared to Hornady. See velocity for different barrel lengths.
Was chamber dry.

Staked primers didnt move.

 

[FeMan]

The factory primers may have a thinner and/or softer cup. Are they nickel plated! As mentioned, check fp protrusion. Is your freebore really short? Its not likely with factory rounds but if they are jammed that could be it too.

 

[GLShooter]

Hornady had a streak of that awhile back. Contact them and they will make it right. I hope you have the box.

Greg

 

[boltfluter]

I have read that Hornady Tap loads are loaded very hot from the factory. You may want to consider having the firing pin bushed. Just a thought.

Paul

 

[Laurie]

99% likely that it's firing pin to bolt-face pin aperture fit. A slack fit allows primer extrusion around the pin that starts the 'blanking' process. (What happens to create the hole in the primer cup is actually pretty complex - I read an exposition on this in Precision Shooting magazine 20 plus years ago and IIRC was so long and involved so many diagrams it was spread over two or more issues.)

Answers? The hardest / thickest SR primers available, reduced loads / pressures, and the best solution in technical terms by far, elimination of the poor pin fit by having the pin turned down and a bushing with close-fitting hole installed. Gre-Tan Engineering must have altered thousands of mostly factory rifle bolts over the years. In the days of Remington 700 actions being used for most custom builds for 6BR and its variants, this was usually advised as a near essential job and should be priced into the build costs if at all heavy loads were contemplated.

 

[6bra1k]

look at the TIP of you firing pin...it may not be smooth which is not helping a possible high pressure load..not an over pressure, just at the top

 

[KMart]

How old is the ammo in question. I have had blown primers on older factory loads that have gotten wet several years prior. There was very faint corrosion between the bullet and case neck. You really had to look to see it.

 

[NorCalMikie]

How can a factory round do that?

As in factory loaded?? Probably brass too short for the chamber. (head space issue on that ammo only)
If you're going to use that brass, make sure you don't push the shoulders back too far.

 

[Ozshot]

Thanks all for the information and tips I’m not sure I made it clear that it’s factory 223 rounds being fired in a 223 AI, howa action and bolt with trigger done and safety removal with a 3rd 26” SS lapped and run in barrel around 5-800 rounds. I still can’t wrap my head around 1. It’s factory 223 made rounds being fired in a 223 AI, so pressure less due to fireforming brass regardless of how hot load is it’s still only made for 223 not 223 AI?. 2 if firing pin depth is wrong why am I puncturing factory ammo and not the hand loads even though at 27.4gns 8202 is hot as for a fire forming 223 round? Ammo is 12 months old stored in safe entire time no moisture, barrel not wet. My entire chain of thought comes back too.. if I bought those bullets off the shelf and jammed them in my 223 is it wasn’t AI’d what would
Have happened then??

 

[243winxb]

factory 223 made rounds being fired in a 223 AI

The factory ammo should have a crush fit when closing the bolt? I think.

The piereced primers are from excessive head space?

But primers are crimped in?

Hope someone has the answer, i dont.

 

[NorCalMikie]

Brass "too short" for THAT chamber. (headspace) Round fires, primer tries to back out of the pocket, gets pushed back into the pocket and also gets pierced.
Pass on the firing pin bush thing. Throwing $$$ at it won't fix it!!
Once those rounds that got pierced are neck sized and the shoulders NOT pushed back too far, no more issues. DON'T SWEAT THE SMALL STUFF. Keep it simple.

 

[10XSHOOTER]

Had the same problem with the 53gr factory vmax varmint loads in a factory Rem model 7. I think it's a factory thing on some of the loadings. .223 rounds and chamber.

 

[Woofie]

I think @Laurie has it about right. My .223 RPR was an absolute bugger for piercing primers until I had the firing pin hole bushed since which time everything is golden. I can tell when my pal has shot my ammo -- his RPR has a new Keystone 26" bull barrel -- because his are the pierced primers
My .223 Savage F/TR rifle has a -- hmmm -- generously sized firing pin hole too which doesn't pierce, but can crater some. Using CCI #41 primers -- which are out there right now (Brunos) doesn't seem to hurt accuracy but corrals the cratering nicely.

 

[Webster]

So I went to work up a new load when I changed over guns the other day,
I changed scope between guns too so I had to dial gun in close again before I could work up an accuracy load. I had 6 Hornady 60gn TAP bullets left (223)
That I thought I’d use to get it close on paper before I started working the load up. I punctured 4 of the 6 primers!. I had to work load up anyway as I needed gun for work that night and barrel is shot on other gun. Worked up a hot but accurate fireforming load of federal primers 27.4gn ADI 8208 with 52gn Speer HP halfway up neck and no pressure signs or blown primer. Have had 300+ rounds through since and not a problem….. any thoughts?? How can a factory round do that?

Why do you think you need hot loads to ff?

 

[sneakboxer]

I saw primer issues at the small arms firing school at Perry in 2021. We were shooting Hornady 75gr match ammo out of Match A2 uppers. On day one there were some popped primers so all the rifles were cleaned over night. The next day this same ammo was removed from the line mid match due to multiple blown primers. I had two rounds that vented through the primer before the ammo swap. The one case we found looked to have burned threw the shoulder of the primer and the other was a classic blanked primer. So maybe it's just a factory ammo issue?

 

[Clark]

It has been my experience that, in an overload work up, the 223 case head will fail before the primer would pierce. As a result, I have almost never seen a 223 primer pierce.

Same for the weaker belted magnum case heads.
Same for even weaker Mauser case heads [270 or 250sav]

But the 6mmBR case head with small primer pocket and Mauser outside dimensions is stronger than the primers. On one hunting trip, I had to disassemble a 6mmBR Rem 700 bolt, and remove many primer divots that were jamming up the bolt.

What does it all mean?
I would suspect the rifle's firing pin or firing pin hole.

 

[Ozshot]

Why do you think you need hot loads to ff?

I wasn’t saying you need a hot load to fireform, I was just saying that I had quite a hot load in there that wasn’t peircing the primer. I only load hot when fireforming because I’m trying to still gain some extra fps then 223 so the drops and wind hold over are still better then a standard 223 and closer the the 223AI round that I run year round for work. I can only load them as hot as the accuracy allows, and 8208 was accurate in my rifle at 27.4gns

 

[Ozshot]

Had the same problem with the 53gr factory vmax varmint loads in a factory Rem model 7. I think it's a factory thing on some of the loadings. .223 rounds and chamber.

Thanks!