"pierced" primer

[lordgroom]

During the process of depriming over 400 pieces of once fired 8mm Mauser brass I have about 9 shells where the decap pin has punctured the spent primer. The primer is ballooned well above flush right now. I have resigned myself to the fact that I will probably have to discard the brass but any ideas about why this happened or any ideas on how to fix it?

What I have tried:
I have tried to tighten the nut on the Lee FCD, use a punch, press the spent primer back into the case and try the above to remove, and honestly... I tried to pry it out with a finishing nail. Nothing has worked. Any info would be appreciated.

 

[earplug]

Check out the end of your firing pin.
You might have had some damage due to a hot load, weak FP cup or ?
When the primer is pierced, a jet of hot gas may act like a cutting torch to the end of your FP. Once it is damaged you have to polish or replace the tip.

 

[evan price]

I've had some where the primer cup sidewalls were just seized in so tight that the end of the cup broke off, leaving a ring of brass in the primer pocket.
I spent half an hour diddling with the one or two that happened on, (They were .357 Mag brass, which I hate to toss out) but could not find any way to fix them that would not weaken or erode the primer cup and let gas leak later, so I crushed 'em and put them in the scrap bucket.

 

[PowderApe]

Sounds like you may have had a crimped in primer or it was lacquered. Can't see the casehead from the pix, were they military brass?

also check out your depriming pin- you may have broken the tip leaving a sharp point to cause the punctures...

Try to pry the puncture hole open to peen a bit of cup to grab with needle nose pliers or a hemostat (very useful tool- get one!) or just chalk it up to "cartridge case attrition" and pitch it into the scrap brass bin

 

[PowderApe]

...oh yeah, you can also screw in a small sheet metal screw in the hole and pull on that... ...or drill it out with an "ez-out"

May not be worth the energy tho!

 

[lordgroom]

Earplug- The piercing did not occur when firing but during Deprime. Thanks for the feedback. I will try the sheet metal screw and easyout.

 

[PowderApe]

9 out of 400 ain't bad- especially if they were gov't surplus from somewhere as they usually seal the primers with some kind of "super gorilla glue +P" adhesive.... were they surplus??

 

[Mal H]

One tip - learn how to use the manual focus setting on your camera.

If I am reading the headstamp correctly (big if), it looks like they are WW so probably not surplus. As PowderApe said, check the end of your primer punch, it may be damaged.

Do you go fairly slow when pushing out the old primers? You should be hitting the anvil which will spread out the load on the base, but if you hit it too fast, the anvil itself might be causing the puncture.

 

[PowderApe]

One more thought.... are you SURE it happened during the depriming phase and not when you fired the weapon?? MalH is right as the anvil should distribute the depriming pin pressure over a wider area and not simply puncture a hole in the cup.... Something's fishy...

 

[rodregier]

I had some 9mm brass that about 3% would let the decapping pin punch thru rather than deprime. Since I was using a progressive press, it was very exciting trying to unwittingly subsequently seat a primer in a pocket that already had a brass "sleeve" in it.

BANG! Primer fired during seating.

First time around I didn't correctly diagnose what was the problem. Took setting off a second primer (later) to finally determine what was going on.

As near as I can tell, the brass had just enough corrosion around the pockets with the fired primer to make removing them more difficult.

I think I dealt with that brass by separately depriming/resizing it and discarding the problem children with the "flip-top" primers.

 

[PowderApe]

Bang!

...after more than 30 years at it, I STILL have to go change my shorts when a primer goes off during primer seating!! It does happen now and again but to reassure those newbies out there thinking about starting to reload- it's really no big deal (after the initial butt puckering startle) and no damage is done! It's GONNA happen- it's just a matter of WHEN not "if" (class: use those safety glasses! Protect them eyes! You only have two of 'em!!) Besides- it PROVES the old ticker can go well over 100mph and still be vertical!!

...and THAT'S why you don't prime a round that's been loaded and you later notice the primer's missing (that too happens!!)

 

[spencerhut]

Okay, maybe it will happen to me, but I've never had a primer go off yet.

 

[rodregier]

Spencerhut:

How many rounds reloaded? Any progressive press usage?

I've lost count, but probably significantly over 50K.

 

[Zak Smith]

Just a note, you can usually fix the problem with out of focus close photos by using the "Macro" mode.

-z

 

[lordgroom]

Macro and manual focus. It was late, I was tired, and at that point in time my newborn was not crying. I was doing my best. I will work on it for later posts.

I am absolutely certain it did not happen during firing. The brass is new to me, purchased from a forum member. It was military with a primer crimp. The head stamp says:

7.92 MM 42


The pin could have been damaged but it has since broken and has been replaced. I probably was not raising the ram slowly, but at a reasonable pace.

 

[PowderApe]

Sounds like old WWII vintage surplus ammo from 1942! Probably had corrosive mercury based primers too, which, over those 66 years, corroded the primer cup and weakened it somewhat. Those primers were staked/ crimped AND lacquered which- over the course of those 66 years, probably bonded the primer cup to the primer hole like a chemical adhesive "weld" Since your depriming pin broke and had to be replaced about that time too (coincidence??) it may be a contributing culprit as well.

I'm surprised they fired in the first place and I'm not entirely convinced it happened during decapping but may have actually happened upon firing and not noticed until the decapping pin went totally through it!!

Either way- pitch them into the recycle bin- you have 391 "good ones" ... Be aware those "good" cases may fail soon and be ready with a broken shell extractor. Those cases were war production and were meant to be used up quickly and not stored for 66 years! Quality of manufacturing may be questionable as was the intervening year's storage conditions...