Unusual malfunction .30 Luger case
 

Earlier this week at the range, I was testing a recently acquired 1906 Model Parabellum "shooter", .30 Luger caliber. All went well for perhaps 20 rounds of Prvi Partizan ammo. I then tried Fiocchi (one round in the magazine). Three rounds fired OK but would not push the toggle back far enough to hold open. I then switched back to the Prvi but the pistol would not chamber the round. Upon inspection I discovered the last .30 Luger Fiocchi round had irregularly sheared off and not extracted. A good push with a cleaning rod and patch from the muzzle end, and it came out.

The photo shows the sheared round and a healthy Fiocchi round from the same box for comparison.

The pistol and extractor appear fine. The teaching of the experiment is that the pistol prefers Prvi ammo, but I'm wondering what could cause such a malfunction?

Me too. What does the sheared-off portion of the cartridge case look like??? What about the butt-end of that case??? Take pics of both, looking down at the edges of the case...

I looked everywhere for the butt portion but couldn't find it.

I'll try photos tomorrow of the sheared edge. It is a taper, not ragged.

Your case looks like a HP rifle casing that has been fired and resized too many times. Of course neither of those fit your situation. Incipient head space separation is I think what they call the rifle failure. I have never seen this in a pistol before. Thanks for the picture. I wonder if the chamber has been checked to see if it is in spec. Go/no go gauges check.

I would say it was simply a defective case.
Defect in the drawing of the case that escaped any inspection; I would expect it happens every "x" thousands of cases that are made.

Nothing to do with the luger or the shooter; just bad luck! ;)

My WAG would be a case failure due to a manufacturing flaw. This is the first example of a 30 Luger case "separating" that I have seen. Thanx for showing it.

Thanks to all for the comments. The case exhibits somewhat uniform thinning, with wall thickness visibly decreasing just forward of the separation line. I agree that it seems like a manufacturing defect in the case.

Sorry to revive an older thread, but this happened to me just today with the same Fiocchi ammo. Nothing looked or sounded different firing, but the toggle locked back despite having 7 rounds left, and the back end of the casing which sheared off was still hooked on the extractor. I managed to move the front portion of the casing a few millimeters using patches, but haven't had any luck getting it all the way out.

I have a jag with o-rings that fits very tightly to the bore; I was able to push the case out by placing a patch on this and pushing it through from the muzzle end.

Un-fortunately, you got the second one after "x-thousand" cases.:eek:

Albeit rare, manufacturing defects happen. This week a local friend found a round with a reversed primer.

The case separation is happening just above the thicker web near the base of the cartridge. It's an adjustment problem with the die used to draw the cartridge case from a bronze pellet. Over-drawing the cartridge at this point creates a very thin area that can't tolerate the stretching caused by firing.

Your gun's chamber may also be worn too large, making the stretching more extreme. There are techniques for casting the chamber and measuring it for specification.

Base separation is always difficult to clean up after. At least the gun won't generally go back into battery after the failure.

On your first picture of the failing recovered case front, you can also see how far off the position of the cartridge shoulder is. If I remember correctly, this case headspaces on the shoulder of the cartridge. Obviously there is something very wrong here from the shape of the fired cartridge. It's almost as if the gun was out of battery and in the process of extracting while the powder was still burning and expanding, forcing part of the shoulder against the rear chamber wall. This could be caused by defective or contaminated powder burning erratically.

After trying a few different size patches, I finally got the rest of the casing out.

So the general consensus is to chalk it up to bad luck/manufacturing defect and carry on? This unnerved me a bit, the few magazines I've tried of PPU functioned fine, I may just stick with it from now on.

Wire brush the chamber well, and move on.
Lightning seems to strike on the .30 Fiocchi, causing the case separations. ;)

That case expansion is abnormal. Double check that it's in .30 Luger caliber (see the FAQ for photos) and measure the chamber to see if it's in specification.

I've never seen that much case expansion in any handgun using the proper ammunition.

The SAAMI cartridge specifications are here:

http://saami.org/specifications_and_...MI_CFPandR.pdf

(Yes i know SAAMI wasn't around when Lugers were developed, but their specs are useful).

See pages 36 and 43 for dimensional drawings. The .30 Luger cartridge case has a considerable taper. it almost looks like your chamber was reamed out larger than the base. It almost looks like it's been loaded and fired from a 9mm chamber.

Interesting position of the shoulder on the fired round.

That's what makes me think that the .30 Luger round is being fired from a 9mm Chamber.

The .30 Luger chamber is tapered like the cartridge. The fired case shows squared off expansion in front, which is what you'd see in a 9mm chamber.

Surely he has fired other rounds!
What do they look like?

Sorry, been tied up with work. Definitely a .30 Luger, a 9mm won't even come close to chambering. I see the neck is abnormally long on the bad round.

left to right, live PPU, empty PPU, empty Fiocchi, Fiocchi lightning strike.

Wonder how the overall length of the separate two parts compare to a good fired case?

What does the headstamp say on the separated case?

Just curiosity here.......the abbynormal neck is a puzzler....could just be the pict I guess.