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.

If the neck WAS too long it would extend beyond the chamber headspace and as the cartridge is fired the cartridge mouth would be pressed into the actual barrel..pinning it in place. Could make it difficult to extract.

A bottleneck cartridge should headspace on the shoulder. The SAAMI spec I pointed to earlier shows this measured to the middle of the bottleneck shoulder.

It might be that someone took a 9mm reamer to the normally tapered chamber of a .30 Luger chamber... The chamber should be .3918 inches where the thick web of the case ends and .3805 at the start of the shoulder.

I'm only speculating without a cast of the chamber or good photos.

Could be most anything, including a simple defective case.

100% agree. No need to overthink it.

Nothing wrong with thinking it either. I have lost track but I don't believe we have ever been able to see the base of this cartridge. That would be a helpful clue to determine if over pressure was a factor.
A careful analysis of a problem like this seems prudent to me.

http://forum.lugerforum.com/showpost...5&postcount=13

Or do we need to also see the head of the case?

Maybe it helps to go back and read the original post,
two rounds fired ok, then switch of ammo and the separated case was discovered.

Perhaps 4scale will come back an add a little more to answer some of the questions posed;
like is it really a .30 luger? Does it shoot ok with Privi ammo?

OK,,very confusing thread..4 scale is the original poster with a sheared case..then ttarp shows a case with the base present in post #13 THIS case looks like it fired out of battery. Or at least with the case partially out of the chamber?
4 scale says he was unable to find the base of his sheared cartridge?

Yes Jerry it is bit of a confusing thread with two separate collectors showing a similar malfunction.

I've long since disposed of the sheared case so I'm unable to examine the shoulder. The shoulder of the sheared round does look long in the photo in post #1. As I recall it did take a good shove to drive the sheared case out of the chamber, so I'm wondering if maybe Jerry is right in his post #21 that the long neck is the culprit.

The pistol used to fire the sheared round shown in post #1 of the thread was a Portuguese 1906 with the royal crest scrubbed off. It has performed flawlessly with perhaps 100 rounds of .30 Luger Prvi Partizan ammo since the sheared case. I have verified the pistol is chambered for .30 Luger (a 9mm Luger dummy round will not chamber). After considering all comments I believe it was just the one defective round. But, next range trip I'll save some ejected cases and compare to unfired ammo to see if something is going on.

I'm sorry for the confusion, I should have started a new thread.

At any rate, after a good cleaning, went back to the range and fired about half a box of PPU, and then went on to finish up the box Fiocchi without issue.

Thanks for everyone's help, and I'm sorry again for the confusion.