Live round ejected with previous spent casing - ideas?

P

PakWaan

New member
My new Sig P938 is ejected live rounds. The gun is new, bought it last month, it has a total of 700 rounds through it. Today I ran 100 rounds through the gun, using 2 different magazines, each loaded with 6 rounds every time. On 5 occasions, after shooting 5 rounds, the slide locked to the rear and the gun was empty. I found a live round on the ground each time.

During one of the cycles, a live round is being ejected with the spent casing. But since it goes bang again with each trigger pull, I'm guessing it must be the last round in the magazine that gets ejected, because I can't imagine it happens in the middle of a magazine and still loads the next round in addition to the one that got ejected.

It stumped the gunsmith at my LGS today, where I was shooting it.

I was thinking magazine lips or springs, but it happens with 2 magazines and they are both new. I borrowed a new 3rd magazine from the gun store, and twice, on the last round of the magazine, this is what I got:

sig1.jpg


I just got it back from Sig yesterday, because it wouldn't feed hollow points. They polished the feed ramp and now it feeds HPs with no problem. Sounds like it needs to go back to the factory again.....
 
The only way I can come up with for that picture to happen is if the magazine is releasing the round early. That would also be consistent with live rounds ejecting.

That means that:

1. The feedlips are too widely spaced apart.
OR
2. The feedlips are too flexible and/or the magazine spring is way too strong and is forcing the follower up with enough force to spread the lips apart.

The fact that it's happening with more than one magazine is strange.

The feedlip spacing on the magazine should be something like 8.4mm to 8.6mm. I'd measure the spacing with magazine unloaded (follower all the way up) and then again with the magazine disassembled so the follower is totally out of the picture.
 
Weak mag springs and/or spread feed lips. As already commented, the mag is releasing the last round too early. Since it's always the last round, that suggests it's probably weak springs rather than spread feed lips.



[Must resist temptation to point out that the OP should have bought a Colt.]
 
Sometimes, it can be a combination of things, all contributing to the problem.
In addition to the mag springs, a low tension extractor and short overall length cartridges could be culprits.
Maybe.
 
If it didn't do this before Sig polished the ramp, and now it does, then obviously I'd suspect that. The round in the picture got hung up on something that it would not have hung on before the servicing, and didn't feed. Why it's the last round, I don't know, but that's when the mag spring is at it's weakest. If you load one round in the magazine and cycle the slide, does it hang up?
 
Are you sure it's the last round? I'm thinking it might be the first cycled round where the mag spring tension is highest. So if the mags lips are out of spec, it would easily spit two rounds out at the same time.

You should go shoot it again and look for the round where the problem occurs.
 
Use a permanent magic marker to NUMBER the side of the cases before you load them in your mag. You'll know pretty quickly which live round is being ejected...
 
Edited.

That is a light pistol with a relatively heavy load. I think what is happening is that as the magazine empties and there is less tension on the magazine spring, recoil is causing the gun to come back while the top round in the magazine tries to stay where it is. That results in the round jumping out of the magazine without the slide pushing it out. With the round gone, the slide catch can lock the slide back. But the round is not fed since the slide is locked back, so it is free to fall on the ground. If the slide doesn't lock back, the round can jam between the barrel and slide.

Jim
 
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I'd talk to someone where you had it repaired before and tell them they created another problem. Send it back and tell them you would like a replacement. If it is a few hundred or a few thousand dollars on a gun it is still your money and you should expect a quality piece.
 
Let some one else shoot it to make sure your not limp wristing the gun.
I find it odd that both mags are repeating the same failure.
 
Interesting twist. When this happened a few days ago, I was firing a combination of Gold Dots and Golden Saber - both hollow points, since I had just gotten the gun back from Sig because it wouldn't feed HP ammo. Yesterday, I put 200 rounds of 115 and 124gr FMJ through the gun without it ever happening once. Today, I put 50 trouble free rounds of FMJ through it again, then switched to HPs. Out of 5 magazines of HPs, it happened 3 times, always with the last round. I switched back to FMJ and the problem went away. So it is an issue with HPs only.
 
It it possible that this is a weak magazine spring and the HP is hanging in the feeding while the slide pushes the back of the case up and out?

I would try cycling many last rounds by hand as was mentioned.
 
In 1911s this issue would likely be caused by (in decreasing likelihood) a weak magazine spring, overly strong recoil spring, or ramp issue. It might also happen if the mag's feed lips are spread too far. So, I would try a different magazine first and then ship it back to Sig. Even though you have the same problem with two magazines, whose to say there wasn't a bad batch of magazines.
 
I talked to Sig today, they want the gun back again, so I'm shipping it off tomorrow along with the magazines. We'll see what they come up with.
 
** Follow up: After 2 more trips to Sig, the issue appears to be fixed. The 2nd time I sent it back, they said they couldn't duplicate the issue and returned it having done nothing. I took it to the range and it did it again. I had the gunsmith at the range fire it, and it did it to him too. So I called Sig and told them I was going to continue sending it back until they fixed it. On the 3rd trip, they replaced the magazine catch spring. Since getting it back this time, I've only had time to get to the range once, but put 15 mags of hollow points through it with no problems. Hopfully I'll have time next week to put another couple boxes through it and pronounce it cured.
 
I know this is an old thread..but..I just bought a new 1911 C3 and took it to the range for its first time and its doing this same weirdness. everything seemed perfect except it seemed like there were fewer rounds in the mag than i thought a couple times. as i was cleaning up i find 2 live rounds on the counter and floor! the only thing that i was surprised about was how strong the mag springs are! i really had to work at getting the last round in the mag. anyway...just so that you know this is still a happening thing!
 
Invited into this one from afar...so...ok.

In 1910, John Browning put a little bitty bump on top of his 1911 magazine follower.

And now you know why.

Cheers!
 
I agree. My Bersa Thunder did this a few times. It also frequently jammed the last round nose up. After closing the mag lips slightly, problem solved.
 
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