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Thread: Extractor issue?

  1. #1
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    Extractor issue?

    Fired off a few rounds the other day (semi) and noticed marks on my casings that I thought were unusual.

    Is it normal for the ejector to leave marks like this?


    What about scuff marks and scratches on the casings like this? -- The all pretty much have these exact marks on them.


    Now for this one, I know this isnt normal. I have slight extractor nicks which I know could be a sign of over-gassing...


    but after closer inspection, I found the cause which is a slight deformation on one side of my extractor.

    What could possibly have caused this? Is it safe to just sand it down and just forget it ever happened or do I have gas issues?

    Carbine in question is a 14.5 1/7 with feedramps Bushy sitting on a F/A lower, Colt BCG, H2 buffer -- Relatively new spring as it is a relatively new carbine. LEss than a hundred rounds though it. -- the above photos being the 61st to the 93rd rounds.
    Last edited by Col_Crocs; 07-31-09 at 04:03.

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    Too much extractor tension?

    I had one recently with so much tension it wouldnt let go for ejection.Left similar markings on the case rims.

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    Was thinking that but I only have the spring with the blue inset(if the spring itself is different on the ones with black insets.).
    What did you have on yours? What did you switch it down to?

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    Ejector Mark- Normal. The case pivots on the ejector during extraction/ejection leaving this typical marking.

    Case Scuff Marks- Any problems with extraction? Do you clean the chamber with a GI Chamber Brush?

    Extractor/Case Rim- It appears that your extractor is not grabbing the case evenly during extraction. The extractor lip should grab the case rim evenly and from both sides of the extractor, not from one tip only. This could be due to an out-of-spec extractor, or bolt.

    Do you have another extractor to swap out and trouble shoot with?
    Last edited by Quib; 07-31-09 at 07:49. Reason: Added bold.
    “A leader is best when people barely know he exists, when his work is done, his aim fulfilled, they will say: we did it ourselves.” -Lao Tzu


    http://quibphotography.com/

  5. #5
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    Quote Originally Posted by Quib View Post
    Case Scuff Marks- Any problems with extraction? Do you clean the chamber with a GI Chamber Brush?

    Extractor/Case Rim- It appears that your extractor is not grabbing the case evenly during extraction. The extractor lip should grab the case rim evenly and from both sides of the extractor, not from one tip only. This could be due to an out-of-spec extractor, or bolt.

    Do you have another extractor to swap out and trouble shoot with?
    None but yes, I do clean it with a GI chamber brush. Not too extensively, just a a couple of turns.

    What couldve caused the extractor deformity? I have another one I could use but How about sanding it down?

  6. #6
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    Quote Originally Posted by Col_Crocs View Post
    What couldve caused the extractor deformity? I have another one I could use but How about sanding it down?
    The extractor deformity could just be a machining flaw. Can’t comment on sanding or re-profiling the extractor. I’ve never tried this. For reliability sake, I’d recommend just replacing the extractor.

    I helped another AR owner once with a similar problem. In that case, the lack of full extractor contact was due to an improperly machined bolt.

    Your extractor problem could be due to either;

    a) The extractor pivot point drilled off center.
    b) The bolts extractor pivot points drilled off center.

    If you have a new, serviceable extractor, try dropping it in and then on your next range trip, check the spent cases for proper, full extractor engagement. The spent case should have a full extractor “print” on the case rim.
    Last edited by Quib; 07-31-09 at 19:45. Reason: Clarification
    “A leader is best when people barely know he exists, when his work is done, his aim fulfilled, they will say: we did it ourselves.” -Lao Tzu


    http://quibphotography.com/

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    Thanks! I'll see if I can actually measure both and compare them to a good bolt/extractor set.

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    No problem, glad to help.

    Here’s a pic I took of a couple spent cases from my carbine, showing the full extractor print.



    Another thing I might add about the ejector “smear” on the back of the case. This can be reduced or eliminated by removing the ejector and chamfering the edge of the ejector face. Often times a sharp ejector face can actually remove brass material from the case. This will show up as brass flakes on the bolt face.

    I chamfer my ejectors by chucking them in an electric drill and running them in a piece of crocus cloth with a little bit of CLP as lube.

    I can get a pic up shortly of one of my ejectors.

    ETA: Ejector chamfer pic added.

    Last edited by Quib; 07-31-09 at 20:17. Reason: Ejector chamfer pic added.
    “A leader is best when people barely know he exists, when his work is done, his aim fulfilled, they will say: we did it ourselves.” -Lao Tzu


    http://quibphotography.com/

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    Great idea! Thanks!

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    Quote Originally Posted by Col_Crocs View Post
    Great idea! Thanks!
    No problem, hope that info helps.

    Did you get a chance to do some comparison dimension checks between bolts and extractors?
    “A leader is best when people barely know he exists, when his work is done, his aim fulfilled, they will say: we did it ourselves.” -Lao Tzu


    http://quibphotography.com/

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