Distorted 9mm Case

[Ej3]

I had a CWP class today and two people shot 9 mm in the same lane. Both shot Federal ammo, but one set of 50 cases was distinctly stained/discolored, with one case in particular extremely distorted. I believe that these were shot in a S&W M&P9 M2.0 9mm with 5-inch Barrel.



What is the likely cause for this case distortion?

 

[barnetmill]

I think somehow or other that distortion was there prior to that particular cartridge being fired. I say it was some sort of manufacturing defect. It was not found on the other cases that you showed. There are some lesser circular marks on some of the fired cases.
I like mysteries. Not enough information to say too much more.

 

[Ej3]

I never thought about it being like that before it was fired. Perhaps she did not notice it when loading it.

Checking the other cases, they range from 0.7425" to 0.745" long. The distorted case is only 0.7385" long

 

[fxvr5]

Measure its diameter at various places.

The head looks really small compared to the rim - they should be nearly the same size.

That's the oddest thing ever!

 

[NedNederlander]

Wow that's a very interesting looking case, and I'm no expert, but I have to believe that's a manufacturing defect. It looks like it got bound up when forming what should be the shoulder below the rim and the brass rippled, or someone lost a bolt and tried screwing their ammo it into something.

 

[czhen]

The first pics shows a 9mm case inserted in a .40 may be.

 

[Ej3]

The first pics shows a 9mm case inserted in a .40 may be.

All 9 mm, no .40 shooting today

 

[Walkalong]

That's the oddest thing ever!

Agreed.

 

[Sneakshot92]

Could they have been a batch of reloads with the crimp and or seating die set incorrectly deforming the case? Or were they brand spankin new factory loads? I use the factory packaging to transport my reloads to the range. No laws against that last I checked anyways.

 

[Ej3]

Definitely new factory loads.

 

[Sneakshot92]

Definitely new factory loads.

That means something was way wrong with the gun, assuming the cases weren't deformed before packaging for retail.
Just another example of why some people open boxes of centerfire ammo and inspect them before purchase.

 

[Obturation]

That first picture looks like the base of one of those little light bulbs for a vanity . it's too weird, can't believe it extracted, the head looks much smaller than the body.

 

[NedNederlander]

After looking at the pics again it very well could be from a gun issue regarding the chamber, because that's the worst soot stained cases I've ever seen from 1x fired factory ammo, so much so it looks years worth of tarnish. And, interestingly enough the rippled case has no soot stain past the ripples... because the ripples sealed the chamber at that spot? I would have a hard time believing anyone could load that cartridge looking tike that into a mag with out seeing or feeling the problem.

Measure its diameter at various places.

Would like to know this as well.

 

[Jim Watson]

Hangup in the machine turning the extractor groove and rim.
The real question is how it got through inspection.

 

[Ej3]

Hangup in the machine turning the extractor groove and rim.
The real question is how it got through inspection.

It certainly appears to be the cause. I was able to get a better photo with natural light, but with less reflection. I was also able to get a decent photo on the inside of the case. The rim and extractor groove measurements are comparable to the other FC cases from the same box. Looking down at the primers, the bad case is in the center. I also noticed that the rim is lacking the slight bevel present on the good case.

 

[barnetmill]

It certainly appears to be the cause. I was able to get a better photo with natural light, but with less reflection. I was also able to get a decent photo on the inside of the case. The rim and extractor groove measurements are comparable to the other FC cases from the same box. Looking down at the primers, the bad case is in the center. I also noticed that the rim is lacking the slight bevel present on the good case.

View attachment 929150 View attachment 929151 View attachment 929152 View attachment 929153 View attachment 929154 View attachment 929156

I suggest you notify FC and see if they want to examine the case. They would likely appreciate seeing the box it was packed in for the lot number.

 

[edwardware]

That's a case forming mistake, from the factory. If the chamber was ribbed like that, ejection would require a hammer.

Keep it, you'll probably never see another.

 

[Cemetery21]

Agree on the factory mistake - as Mr. Watson mentioned, the cut for the extractor groove goes way up the case then chatters. It's a wonder it didn't cut through the thinner case wall at the middle of the case length.

 

[Nature Boy]

I'm in agreement with others that say it's a manufacturing defect. I'm surprised the student didn't notice it when loading the mag

 

[Ej3]

Unfortunately by the time I picked up the brass, my students had left. And they collected and left with their ammo boxes. And even if I had the boxes, I could not distinguish between boxes/lot numbers. Two boxes of Federal were shot back to back. But I will still notify Federal for their information.

I am also surprised it was not noticed. But I have them dump 50 rounds into a side pouch so they can holster and have two hands free when loading magazines. Since we shoot as multiple distances (not stationary at a table with moving target), it is more convenient to use the side pouch. I would assume that they grabbed a few rounds in one hand and did not focus/look at each round as they loaded the magazine.

 

[tightgroup tiger]

I can't imagine how someone, even with no experience, would't think something wasn't wrong when they picked that up, if it's real.
I have some problems with what I'm seeing in your picture.
First, I don't know how that round would have chambered.
Second, I don't see any dirt past the first ring. Highly unlikely.
Third, the brass looks like the distortion was made after if was fired. The brass is just to bright and clean.
Forth, If the base is that thin, from what the dia looks like, why is it not blown out to the same size as the mouth end of the brass? It is noticeably smaller in dia. It should be really thin at that area and it shows not distortion at all.
I'm not buying in to this.
I'm not accusing the OP had anything to do with this, but after 48 years of reloading, I just can't believe what I'm seeing in this picture.
That case looks like it was machined after it was fired.

 

[fxvr5]

That case looks like it was machined after it was fired.

So, you're saying it was fired, then someone machined the fired case, then returned to the range and tossed it among the fired cases.

 

[Ej3]

It is real, not machined, not reloaded (and not photo shopped if anyone is wondering). I did think something was wrong when I picked it up, and assumed it was a gun problem. That is why I posted it on the THR.org knowing I would get credible and insightful feedback. And after receiving that feedback, I agree that it was a manufacturing defect. I did speak with Federal Ammunition and sent them my photos yesterday, but have not received any feedback except that it would be sent to their quality assurance team.

It did chamber and appears to have sealed at the first ridge. So the bottom half is shiny because it was a shiny new cartridge, out of a factory new box. It was likely purchased at Palmetto State Armory. So I am assuming it was not tampered with before being shot in my class. And, I can assure you it was not machined after the fact.

 

[GooseGestapo]

A factory defect that got past the inspector.
Probably occurred after breakdown/tear down of equipment before it was completely reset.

Ammo is mass produced to the tune of millions. A few defects are bound to get through.

But, it IS an interesting defect.

 

[Nature Boy]

I’m looking forward to what Federal says, if they ever say anything.

I found this primer in a brand new package of CCI small pistol primers

it looks like it was fired



But pulling out the anvil shows that it had no compound in it