Is this a problem?

Discussion in 'General Rifle Discussion' started by elglockeroloko30, May 10, 2014.

  1. elglockeroloko30

    elglockeroloko30 New Member

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    This is a spent cartridge from my CETME 308. Actually, it won't eject brass shells. I fired 40 of these which i think were American Eagle, without a hickup but i noticed that they look the same as the brass ones that did not eject and wondered if there is a problem with the rifle. Thanks in advance for your insight. ImageUploadedByFirearms Talk1399749000.601696.jpg


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  2. therukh

    therukh New Member

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    Those look like my empty's from my H&K. Looks like a fluted chamber but I don't think it's a problem.
     

  3. elglockeroloko30

    elglockeroloko30 New Member

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    What does “fluted” mean?


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  4. fa35jsf

    fa35jsf New Member

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    Fluted means there is recesses cut in the wall of the chamber. Fluting is more common on the outside of barrels to reduce weight and dissipate heat than inside a chamber.


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  5. kfox75

    kfox75 Well-Known Member Supporter

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    Field strip the rifle, and inspect the chamber and gas system. Use a chamber bush on the chamber, and make make sure your gas system (block, tube, etc.) is thoroughly clean. if the problem persists, try a different brand of ammo, and talk to a smith.

    This is just my own thoughts on general semi-auto issues. I have no experience with the CETME .308.
     
    Last edited: May 10, 2014
  6. Mercator

    Mercator Active Member

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    I think that's his (OP) problem as well. The CETME has no gas tube, it's all delayed blowback. The rifle doesn't know brass from steel, there has to be a minuscule difference in the headspace or what not, but I better stop here.
     
  7. Sniper03

    Sniper03 Supporting Member Supporter

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    Eagle,

    I do not believe my CETME has a fluted chamber in it! But I did find this that I might share with you for information only!
    Beware of Commercial .308 and Fluted Chambers
    Posted April 30, 2013 in News, Other Gear & Gadgets, Rifles by Alex C. with 83 Comments

    My good friend CJ is a real whiz at building H&K roller locked stuff. Back in the day when G3 parts kits were affordable and flowed into the United States like water anyone could build one for a few hundred bucks. The problem however (aside from relative build difficulty) was that a true G3 spec chamber does not like commercial .308 Winchester ammunition. G3 rifles have an internally fluted barrel. This aides in extraction and prevents the possibility of an extractor breaking, and a shell sticking. The gas from the discharge is forced back and around the spent shell blowing it out of the breech. So, in the event an extractor breaks, or some ammunition failure, you will definitely get the spent case out of the weapon. With no extractor at all it will eject a round, or at worse cause a partial ejection which requires you to pull the cocking handle and drop the round out. The problem with this is it mangles brass. CJ found this out the hard way:
    What you see here is what can happen. This was commercial .308 fired in a properly built G3; It is very dangerous and can kill you. *******You must use 7.62×51 NATO if you have a true G3 spec barrel. As you can see, the top of that round has the aforementioned flute marks – that’s what a spent shell looks like – it gets ruined. Now, if you notice… that’s only 1/3 of a shell, the rest of it was ripped off. Since commercial .308 is much thinner cased, when the round discharges the more pliable case expands and actually sticks in the flutes, and given the power of the round, the extractor literally rips the back of the case off, leaving the front of the shell stuck in the barrel. The next round was cycled in with such force, it actually slid itself through the remaining case neck. Luckily CJ noticed the rifle wasn't in full battery and didn’t fire it (that would have been catastrophic).
    H&K 91 rifles had a much looser chamber to allow the firing of .308 ammunition, and modern manufacturers of G3 pattern rifles seem to have adopted a similar chamber. Just beware of what can happen and be safe!
    Special thanks to CJ for sharing this information and photograph.

    With that said some serious research is warranted!

    03
     

    Attached Files:

    Last edited: May 10, 2014
  8. Mercator

    Mercator Active Member

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    I think Sniper may be right on the money. I forgot that your CETME is in fact a 7.62 and "not exactly" a .308.
     
  9. elglockeroloko30

    elglockeroloko30 New Member

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    It has .308 writen on the frame.


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  10. jpattersonnh

    jpattersonnh Active Member

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    Does not matter. The Cetme is 7.62x51, not .308. You are hammering your receiver and creating a very dangerous situation. The roller lock bolt is VG, but if you keep over pressurizing it, it will fail. Your face is behind it, so you decide.
     
  11. Mercator

    Mercator Active Member

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    I wonder who stamped 308 on the barrel (or the receiver?), Century Arms or the original parts manufacturer.
     
    Last edited: May 10, 2014
  12. jpattersonnh

    jpattersonnh Active Member

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    .308 is found on many "surplus" rifles, Guess it is cheaper the 7.62x51! All the info is stamped on the mag well of the lower.
     
  13. 303tom

    303tom Well-Known Member

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    You can find it anywhere in black & white..................Both civilian .308 Winchester and NATO 7.62x51mm ammunition may safely be used in the CETME !............Do I know what is making the marks on that case..........NO !.
     
  14. Mercator

    Mercator Active Member

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    Care to share how it shoots? I've been drawn to this great design, but never enough to dump 1K on it. No gas system is a plus, if that works!
    Specifically: does it eject forward from you?
     
  15. Mercator

    Mercator Active Member

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    You know better than I do if you read the manual. As to "who done it", the Eutopeans might stamp 308 MEANING 7.62 in translation from the metric system. Does it say .308 WINCHESTER?
     
  16. willshoum

    willshoum New Member

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    Small investment...............

    6 inch dial calipers and small bore gauges........................And a calculator...................
     
  17. Mercator

    Mercator Active Member

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    Update

    This is the CAI CETME receiver. pix819419865.jpg This is from the Manual.
    End of discussion? Not yet.

    The Manual does not guarantee the headspace to be correct. It is up to YOU to measure it. I have not seen another "new" gun manual that makes knowing the HS my responsibility. Calipers not included...
    I think willshoum has a plan.
     
  18. elglockeroloko30

    elglockeroloko30 New Member

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    It is very fun to shoot and very acurate as well. The recoil is there but i find it very manageable. Drawbacks: it is very heavy, taking out the magazine is a pain and pulling the charging handle back is also a pain.


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