What's causing deformed casings upon ejection fr/semiauto?

Discussion in 'The Ammo & Reloading Forum' started by user, Sep 24, 2008.

  1. user

    user New Member

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    These came out of my Kahr K9 today, 9*19 Federal Premium HST. 124 grain. The one on the right was the worst, and there were a few like the one on the left, out of one magazine of 7+1 bullets.

    I'm wondering what is the most likely cause or causes, and do I care? I've run about a thousand rounds through the thing, and never had any problem whatsoever with it, nor have I notice the flattened sides of the cartridge cases before.

    [​IMG]

    [​IMG]
  2. armedandsafe

    armedandsafe Guest

    That nick on the rim of the right bothers me more than the dented mouths.

    Dented mouths are not terribly unusual for semiautos. a different spring weight will usually take care of that, but might bring on other problems. The is a range of springs which will operate properly and others which will almost operate properly.

    It could be wear in lockup. At any rate, it appears the ejector is banging the case out sooner than it should.

    The nick on the rim is troublesome to me, as it says the slide is trying to extract the round while there is still considerable pressure left in the case.

    I'm not a smith and don't have a lot of experience in troubleshooting such problems, so those are guesses and what I've learned second hand.

    Pops
  3. muddober

    muddober Active Member

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    I agree that the nick on the rim is more of a concern than the dented case. In time it will break the extractor. I believe that nick is caused by the extractor trying to pull the case in resistance of the case mouth still not out of the barrel caused by too long of an ejector. The dent at the mouth is the evidence that supports my belief. It is obvious to me that the dented case is trying to be ejected to the right out of the the barrel too early or prior to being pulled far enough straight back meaning the ejector is a bit too long. As far as there still being being pressure that I don't agree, because a Khar (I have two of them) lock up some what like a 1911 Colt (barrel drops down to unlock)the bullet is long gone before the action even begins to open and it takes very little pressure to bulge a case that is unsupported by the chamber. There is absolutely no evidence that either of the two cases shown are bulged. I can also tell you that my experience with the Khar company is the best and I would suggest you send them back your gun unless you feel you can trim a little off the ejector yourself. A little to me would be about .025" at a time and shooting it in between until you get it right.
    Last edited: Sep 25, 2008
  4. armedandsafe

    armedandsafe Guest

    Not being familiar with the Kahr, I did not know that it has a lockup similar to the 1911. That makes a definite difference, as you said. That negates my theory about extracting under pressure.

    I think you are on to something, mud. We'll get a real smith in here after awhile who will tell us what is really going on.

    Pops
  5. user

    user New Member

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    A couple more points, then: true, there is no evidence of a bulging case, I've looked at 'em again to be sure. Secondly, the mark left in the primer casing by the firing pin is unusual. It's not a round dot, more like a comma. That indicates to me that the extractor's trying to do its thing while the firing pin's still forward and engaged.

    I haven't formed a picture in my mind, yet, of exactly how these things work and how all the parts do whatever it is they do. Give me a Carter AFB or a Rochester Quadrajet and I can deal with that, but semiautos are still a bit of a mystery.

    So forgive my ignorance, but I am wondering 1) whether the fact that I haven't cleaned the thing in months despite carrying it around will have caused crud to build up and interfere with functionality, and 2) whether I really just need to lubricate the thing more often, and 3) whether it needs a stronger recoil spring?

    Perhaps I should do an autopsy, take the thing apart and see where the marks are of any friction.

    Thanks for the help.
  6. JLA

    JLA Well-Known Member

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    Ill make you a deal user, ill send you my carter 2bbl from my 77' dodge, and you rebuild that and ill get your gun goin for you. Best tool for the job is probably a small bastard file, or an angle file of similar size. place an empty in the pistol and manually eject it, watch he case for ejector contact and chamber clearance. if the ejector presses on the case with any of the case still in the chamber, it needs to be set back somehow. the ejector should contact the case as the mouth just clears the breechface and slide on its way out...
  7. LDBennett

    LDBennett Well-Known Member

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    In a recent gunsmith review of a Kahr pistol in an AGI video, the reviewers found that the extractor did not hold onto the case correctly. The case is suppose to be held up against the face of the slide and not be able to fall off. The review example did not adequately hold the case to the slide face but allowed it to fall off because it was not shaped right where it grabs the case rim. You should be able to slide the empty case under the extractor and be able to shake the loose slide around and the case not fall off. If the extractor does not hold the case to the slide it can fall into the action and get beat up by the closing slide and the extractor and may cause jams.

    While the review gun was not the same model, it may be Kahr's normal design of the extractor and that design may allow the case to fall out of its proper location on the slide face where the ejector can hit it correctly. It might be worth a simple test to see if maybe that's the problem.

    The Kahr seems to be a minature version of the 1911 in some respects. The 1911 has a specification for the amount of force required to vertically pull the case off the slide face from under the extractor. I would expect that requirement should be applied to the Kahr as well.

    Just my thoughts.

    LDBennett
  8. Ed K

    Ed K New Member

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    these problems are discussed in owners manual
    when all else fails read the directions no insult intended
  9. carver

    carver Moderator

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    I think you hit the nail on the head. After looking at those cases my first thought was that it appeared to be be getting caught in the action as the slide closed and loaded another round. I've seen simular cases like these before.

    Y'all be safe now, ya hear!
  10. Skipper

    Skipper Member

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    It isn't getting caught by anything. The 1911 does the same thing......the case is coming back and smacking the slide behind the ejection port. That's why a lot of shooters like to have the area "relieved".

    See behind the port in this pic:

    [​IMG]
  11. LDBennett

    LDBennett Well-Known Member

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    Skipper:

    You are right about the brass swinging on the extractor and hitting the edge of the ejection port when the ejector hits the rear left side of the head of the case. I see it in my brass all the time and can almost count the number of times the brass has been loaded by the little half moon marks left even after sizing. But....

    The marks on the rim tell me that the extractor is having a problem holding onto the rim. The extractor should act just like a hinge and allow the brass to swing out of the port and around the rear edge of the port where the brass gets hit by the edge of the port. I think in this case something more is happening because the rim is marred. The extractor is not holding onto the brass correctly would be my guess. But maybe not????? I'd have to have the gun to check it out to be sure.

    LDBennett
  12. thomas44

    thomas44 New Member

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    I had a Llama 1911 that dented the case mouths like that. I didn't bother having it looked at, just sold it and started buying better 1911's !!
  13. Skipper

    Skipper Member

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    LDBennett, I fully agree; that's a pretty fierce looking extractor mark.......I think he has 2 problems happening at the same time.
  14. user

    user New Member

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    1) It's probably more work to get the Carter 2bbl off the intake manifold in a '77 Dodge than it is to rebuild it. If I recall correctly, it takes two gaskets, a needle valve and seat, one check ball with spring, and an accelerator pump diaphragm. Of course you've got to check the float to make sure it's airtight, and some rebuild kits come with new jets. Cars I can fix; Kahrs, that's something else.

    2) I appreciate the thoughtful analysis of my problem. I'm going to take it apart, clean it up, lubricate and look at all the stuff you guys mentioned really carefully. Then I'll take it out and shoot it again and see what happens. I suppose I'll end up sending it back to Kahr if I can figure it out.

    I did order a milling machine today, maybe I'll go into the "slide relief" business.
    Last edited: Sep 25, 2008
  15. muddober

    muddober Active Member

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    Ed K: Owners manual? I don't need no stinking owners manual. LOL

    I would not mess with the recoil spring and I said before the factory people are top flight and you might be best just to send it back. When I got my first Khar I tried to do an action job and messed up. I told them what I did and they fixed it for free. It does not get any better than that.
  16. user

    user New Member

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    Ed's right. Page 20: "Note Regarding Primer Indent and Distorted Spent Cases Upon examining fired cases, you may notice that the primer indent appears distored or elongated. this is normal for the striker system design of the Kahr Pistols. You may also notice that the spent case becaomes slightly deformed into the shape of a "D" instead of an 'O' shape. This is considered normal for the kahr pistol and was caused by the spent case touching the bottom of the ejection port when exiting the gun. Neither of these two situations are [sic] a cause for concern and it is not necessary to contact the service department."

    I'm still wondering about the scratched up rim where the ejector snagged it, though. Maybe I ought to polish up the ejector, it may have a burr on it or something that's causing excess friction.
    Last edited: Sep 26, 2008
  17. JLA

    JLA Well-Known Member

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    Skipper, thats a damn nice slide. That the Mfg.s card?, Matte Blued?, BM1 rear sight cut?, .330 X 65 degree front sight cut? Long slide?, What did you pay for it???
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