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Thread: New Cetme Owner-Headspace Check?

  1. #1
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    Default New Cetme Owner-Headspace Check?

    New guy Ed here.



    So this was how I did it at the range.

    1. Chamber round
    2. Extend arms fully with ejection port away from me, close eyes tightly behind my range glasses.
    3. Squeeze trigger

    Bang. Still had face and fingers so I assume all is well. Fired 40 more rounds. Surprised with the accuracy of this thing. Iron sights at 100 meters. 3 inch groups. High 12 inches and to the left about 4 inches....but 3 inchers no less. I'll mess with the zero later. Didn't like the stiff trigger so that is off to Williams Trigger Spec for the contoured trigger work.

    SO....how does one check the headspace properly???


    :D

  2. #2
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    http://forums.gunboards.com/showthread.php?t=119870

    Check second post, it has pictures.

    Jim

  3. #3
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    Thanks. Very straightforward.

  4. #4
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    Do your homework. Keep learning about this rifle, plenty of info out there. Just watch out for commercial ammunition. The brass can flow into the flutes and cause a case head separtation. I have seen pics posted on a CETME forum where it left the empty casing in the chamber and chambered another cartridge inside the empty. The next shot may have been out of battery. These are fun rifles, good luck with yours.

  5. #5
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    Directions are great. But don't any use oil anywhere and clean the entire rifle including the Cocking Tube before following directions.
    gw11

  6. #6
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    Got the trigger back from Denny, contour trigger is a no-go on the Cetme so he did the standard work. 10# to 4.5#. I like it. Also picked up magazines from Dirt Cheap at .99 ea. ALL were in great shape....from 1964's up to 1988's.

    I'll post some more after the next range session.

  7. #7
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    Whats your bolt gap?

  8. #8
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    .005

  9. #9
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    Ludicrous

    Are you aware that.005" is not good? .004" is bad- .020" is Good!

    Have you gotten around to measuring the length of your bolt? It should be 1.835" long.

    You might also check into installing +4 rollers in the Bolt, if they are not in there already!

    gw11
    Last edited by gw11; 07-18-2009 at 03:40 PM.

  10. #10
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    I might would have just rather paid for a barrel repress than a trigger job. But I dont know how much you paid. Do your homework, have fun, there good rifles just a different breed of parts gun. RobertRtg will get you +4 rollers and APEX has new bolt groups. I would try a new locking piece, bolthead and add the +4's. Also take gw's advice. It is not complicated, really these rifles.

  11. #11
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    Quote Originally Posted by jdub View Post
    I might would have just rather paid for a barrel repress than a trigger job. But I dont know how much you paid. Do your homework, have fun, there good rifles just a different breed of parts gun. RobertRtg will get you +4 rollers and APEX has new bolt groups. I would try a new locking piece, bolthead and add the +4's. Also take gw's advice. It is not complicated, really these rifles.
    +1, excellent advice. In the manual, bolt gap range is .010" to .018", as ideal, and .010" to .020", as maximum. The advice given above should get you back within the tolerances, if not then a barrel repress will. That's the way these rifles were purposely designed. BTW, Ludicrous, welcome to the jungle!

    Michael
    Last edited by highestangel; 07-19-2009 at 12:51 PM.

  12. #12
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    Quote Originally Posted by gw11 View Post
    Ludicrous

    Are you aware that.005" is not good? .004" is bad- .020" is Good!

    Have you gotten around to measuring the length of your bolt? It should be 1.835" long.

    You might also check into installing +4 rollers in the Bolt, if they are not in there already!

    gw11

    Yes, I have done some reading in the past week about this Century Cetme. I'm gonna try the +4 rollers first. Then barrel repress if that doesn't fix it. Got the press and TIG at work to do it myself.

    Local gun store has a sweet new PTR-91....but they want ,$1800.00 for it.

    :eek:


    I have not measured the bolt yet...if they ground it they did a sweet job. Doubt it has been ground. I will measure it. The locking piece has no wear on the shoulders.
    Last edited by Ludicrous; 07-20-2009 at 06:57 AM.

  13. #13
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    If the Bore and Sight alignment are ok, a Reset of the barrel is not too difficult. Sometimes you luck out and the Trunion Pin Hole was reamed too large and the Barrel has simply shifted Forward within it's slop. If so just press the barrel back in to an acceptable Gap around .018"-.020" [leaving the pin in the hole as a stop] Or if the pin was tight just insert a smaller pin that will stop you at your required depth. Then mill the Pin Hole oversized with an End Mill and then Ream. [because of the different hardness between the trunion and the barrel, you do need to be careful redrilling] this is why I say "End Mill". You can drill it in a Drill Press, but you need to do it in careful steps.
    You can use ZZ Pin Gages from MSC in any size you want. I use Vermont Gage 2" pins for they are R61 hardness.
    With these you do need to cut them to the length of the old pin and slightly bevel the edges to prevent breakage. Just use an unhardened Punch or Preferably a Press.

    Just remember to size the pin at .0015" to .002" over the reamed hole size. [You want the pin to go in Hard] if it goes too easy the Barrel shift when fired. This can be 1 or 2 thou or 10 in Century's reference.

    Also remember to purchase Drills and or Reamers that are in the thousandths, and or combination's with Metric to keep the hole as small as possible.

    I have done this a few times and have found that you can use an old muzzle brake [flash Hiders are too flimsy]. Or make your own arbor that threads on but it has to contact the Barrel muzzle. Other wise it will crush and make a mess. As long as you have a good tight press and you watch the Alignment of the Barrel in the Press it will not harm the Barrel. Or at least I have had great success doing this.

    [A little advice when pressing] Press a little Tap a lot! Meaning apply pressure and tap the end of the press with a Hammer to help release that pressure before applying too much and having the barrel move too far!

    Also at the other end you can use and old HK or Cetme Bolt Carrier turned backwards as a Perfect Arbor against the Trunion , and just add what ever you need to clear the rear of the receiver.

    See Your all Done!


    Good luck!

    gw11

  14. #14
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    Bolt is 1.835 inches long. Good to go.

    My rollers are 8.0 mm.


    Also found out some history on this rifle. It just recently came back from some (?) gunsmith in Arizona. He repressed the barrel and welded the trunnion. He also installed the G3 rear sight. Also refinished the rifle and installed wood to replace the plastic.
    Last edited by Ludicrous; 07-24-2009 at 05:46 PM.

  15. #15
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    Sounds like you now have a New Rifle!

    Have Fun!

    gw11

  16. #16
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    Quote Originally Posted by gw11 View Post
    You have standard rollers and your Bolt is correct at your measurement which equals [1.83622"]

    gw11

    Damn your quick. I didn't even have time to edit. I saw your inches measurement and set the digital caliper to inches. 1.835.

  17. #17
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    I deleted that reply in case I was dreaming!

    Did the person that gave you that rebuild info happen to mention what the Bolt Gap was right after the repress?
    That info may tell you where the pin was drilled at and maybe he used a small pin and it shifted.

    gw11

  18. #18
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    Quote Originally Posted by gw11 View Post
    I deleted that reply in case I was dreaming!

    Did the person that gave you that rebuild info happen to mention what the Bolt Gap was right after the repress?
    That info may tell you where the pin was drilled at and maybe he used a small pin and it shifted.

    gw11

    Unfortunately the guy I got the Cetme from doesn't know much info. I asked what the guy's name was but he was fuzzy on that. All he told me was the gunsmith was rather gruff, took 5 months to do it and his wife has big boobs. So that is the extent of my knowledge.



    Here's a picture of it:

    Last edited by Ludicrous; 07-24-2009 at 06:09 PM.

  19. #19
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    These Guns are certainly pretty when they want to be! That one deserves another attempt at a barrel adjustment.

    gw11

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