M*CARBO Brotherhood

Sub2k: Failures to Eject are endless. Asking for help

I have a new extractor and spring on the way From KT. No idea if it will make a difference. Anyone replaced an extractor? Any tips?

-Scott

phuzzy42 Regular
September 17

If you do a frame-by-frame on the ejection video, it looks like the shell is coming off the extractor early. Normally, the front of the shell rotates to the right when it hits the ejector with the extractor acting as the pivot point, and the shell is kicked out of the receiver. This vid shows the shell coming off the extractor as soon as it hits the ejector, and rotating almost 180 degrees so the open end is facing the bolt, and then it rotates another 180 degrees out of the receiver.

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It’s no biggie. Drive the pin out with a punch, but keep your finger over the extractor when you do so the spring doesn’t fly the friendly skies.

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The bolt is coming back with the shell still on the extractor…

The shell hits the ejector here…

The bolt is still traveling back, the shell is OFF the extractor at this point…

The shell does a 180 inside the receiver…

It continues spinning…

And out the ejection port…

I’m inclined to believe the extractor is the culprit, or at least a major contributor.

Mine gun’s bolt has a little play but not quite as much as yours. It’s from the connection between the bolt and bolt head. I don’t think it’s significant.

Any other brother want to chime in on this?

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Wow. Impressed with everyone’s breakdown of this. I need to take it back to the range and catch a failure on high-speed. So much appreciated.

-Scott

phuzzy42 Regular
September 17

The bolt is coming back with the shell still on the extractor…

The shell hits the ejector here…

The bolt is still traveling back, the shell is OFF the extractor at this point…

The shell does a 180 inside the receiver…

It continues spinning…

And out the ejection port…

I’m inclined to believe the extractor is the culprit, or at least a major contributor.

perma:

Video of play in bolt. Is this normal?

Mine gun’s bolt has a little play but not quite as much as yours. It’s from the connection between the bolt and bolt head. I don’t think it’s significant.

Any other brother want to chime in on this?

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Your videos are very good - they help show what’s really happening. I use VLC to play almost every media file there is - video, audio, DVD, etc. and it’s free. It can do the frame-by-frame and take snapshots like above. I’ve been using it for years.

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Extractor letting go too early can still be caused by a misaligned chamber/bolt interface, with the case sticking and being dragged off the extractor early. Maybe because of the play in the bolt? Mine doesnt move that much, but im still under 1000 rds through it.

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It is a blowback action. Case isn’t sticking; it’s pushing. I’d surface the extractor to eliminate engagement issues with the case rim. Next I’d take a detailed look at the ejector. Is it oriented correctly? Why isn’t it ejecting on impact with the spent case?

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Just a shot in the dark here, is there any sign that the bolt is dragging. The only time I have ever had a fail to eject, I discovered that there was a burr at the front of the charging handle slot. I was slamming the bolt forward when the sub was folded cuz it sounded cool. If there is nothing to stop the bolt face ( like the chamber ) the charging handle impacts the slot and deforms it. Just a thought.

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Right, sorry. poorly described on my part.
I was trying to point out potential friction of the case against one side of the chamber upon exit, due to misaligned bolt stroke. Seems like excess motion, or friction could break the extractor’s hold?

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Thanks, everyone for your assistance over the last week. In the very first reply, to my request for help, Phuzzy42 suggested replacing the extractor and spring. I ordered them that day, and they arrived this morning. Installed them, and took it to the range. For the first time in eight years, it just worked!

Thank you, Thank you, Thank you.

I took photos of the new vs old ejector and spring. The new ejector is narrower, but has a much firmer grip on the rim with that longer spring. Hope this thread helps someone else down the road.

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Glad to hear it, and glad it didn’t cost you an arm and a leg. I think you’ll be happy you didn’t sell this gun - it’s a fun shooter.

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Was that “growth” on the extractor that way from the factory? That couldn’t have been helping you there… :hushed:

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It was that way from the factory. I just assumed they were all that way. My new extractor had a different manufacturing defect. I filed and polished it prior to installation to avoid any new issues.

chilipepper
September 20

Was that “growth” on the extractor that way from the factory? That couldn’t have been helping you there… :hushed:

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Hi,
Just found this thread. Could you please elaborate on the different manufacturing defects?
My gen1 sub2k g19 rams the cases right into front of ejection port as yours did, chewing up the plastic and deforming the front of spent shell.
I AM ordering new extractor and spring right now! based on this thread and your newfound success. I’ve never gotten it to work right no matter what before. It’s one of my 2 gen1’s. My gen2’s are flawless.
Thanks in advance, Nick

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The sub2K gen1 has a smaller ejection port than the gen2. The gen2 includes an enlarged ejection port as a result of the issues you describe.

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Hi,
Thanks for the quick response, yes i’ve gone over both gens w/ fine tooth comb to compare. I’ve got 2 gen1’s, one is for g19 mags the other is for g17 mags.
It occurs to me JUST this very moment writing this, I could have swapped bolts in the gen1’s to isolate the problem. DOH Or could there be a headspace
issue? if i did?

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Hi CatFood,
I just got my Kel-Tec/M-CARBO SUB-2000 back from Kel-Tec to deal with this same issue. I took it out to the range yesterday and now it’s worse. I shot roughly 200 rounds of Remington 115 gain through it yesterday with about 6 FTE’s and all my cases look like the ones posted in this thread. Kel-Tec also ended up replacing the barrel as it was compromised with raised tool marks.


This is the case from the old barrel. I thought the raised marks may have been grabbing the case when fired. As you can see the same marks were transferred to the case.
They also replaced the bolt due too due to scaring along it’s outside diameter which were located and heaviest at the connection between the bolt and the rear weight (no pic :frowning_face:).

Here is a pic of my ejector alignment with the new bolt.


Kel-Tec also dressed up the jacked-up recoil spring pin and M-CARBO sent me a replacement.

My ejector alignment seems to be off from some of the pics in this thread. Question, did you angle the ejector downward and parallel to the bolt?

Bye the way, I noticed that your receiver is pretty clean. I haven’t cleaned mine yet, but this is the Weiler #44113 1" Nylon Tube Brush I use that I found on Amazon for $10.88. It does a fantastic job on the tube.


Thank you in advance!
2A4EVER

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@2A4EVER Hmm, that rip on the side of the case is caused by the ejector. Your extractor looks good on the bolt. How does the ejector alignment look like to the bolt (it’s the little metal tab on the inside of the receiver red arrow in my pic). I bent it up towards the top of the gun.

I’d check alignment before you bend it. Put a spent casing or snap cap in and slowly pull it back. 2 things will happen. It will either eject the casing, or the casing will miss the ejector.

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Note also with the new spring is longer, but lighter to give more travel with less difficulty to come over the rim. These guys know there stuff.

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Hi Cat Food,
Yesterday I took my SUB-2000 apart and modified the ejector to where it’s about .002 to.003" away from the bolts. I was thinking about what you did and it makes sense to move the ejector up so that the case can correctly hit the ejector. I just fired it one time in the back yard and it ejected fine. My wife and I are going to the Tucson Rifle Club today and I’ll run some more rounds through it. Looking good so far, thank you for your input on this irritating problem some of us have.

Ciao,
2A4EVER

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