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CMMG lightweight upper question.

Discussion in 'Rifle Country' started by arthurcw, Jan 24, 2008.

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  1. arthurcw

    arthurcw Member

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    Anyone had any experience with this upper?

    CMMG 16" 1/7 Lightweight Mid-Length Upper w/625" FSB. Forth listing on this page: http://cmmginc.secure-mall.com/shop/?shop=1&cart=938524&cat=61&

    I’d rather it be 1/9 twist. But my Google-fu and Ask-arate have failed me and this is the only midlength light weight upper I’ve found.

    Thanks,
    ACW.
     
  2. rbernie
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    rbernie Member

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    It's VERY nice; I have two (and one of their lightweight 20" models). Accuracy is good, build quality is excellent.
     
  3. arthurcw

    arthurcw Member

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    Do you think you give up too much perfomance on the cheaper 55gr bullets?

    I'll be getting into realoading if I get it, so I can call my own tune. But it would be nice to know if I'm lossing too much with the cheaper plinking ammo.
     
  4. blackhawk2000

    blackhawk2000 member

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    1:7 works fine with 55g. Unless you want to shoot the really light varmint stuff, stick with the 1:7.
     
  5. rbernie
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    rbernie Member

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    The CMMG barrels shoot the 55gr fodder quite well - I've been using the Hornady, Winchester, and MidSouth generic bullets in my handloads with fine success.
     
  6. Soybomb

    Soybomb Member

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    I have the cmmg light barrel but haven't built it into an upper yet. I believe adco will turn down rra barrels to whatever profile you want for a somewhat reasonable fee. Maybe they'd have the 1/9 twist you want although for 55gr 1/7 will be fine.
     
  7. atek3

    atek3 Member

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    I have the CMMG 16" medcon upper 1/7 on my rifle... i love it. tackdriver and reliable.

    atek3
     
  8. Bartholomew Roberts

    Bartholomew Roberts Moderator Emeritus

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    Don't worry about loss of performance between 1:9 and 1:7 on 55gr ammo unless you can already appreciate 0.25MOA at 100yds difference.

    If you want exact numbers, a poster named Molon at AR15.com took two same profile Colt barrels, one 1:7 and one 1:9 and shot 55gr out of them to establish just how much the different twist rate affects accuracy and dispersion. The answer is that the 1:9 DOES shoot better; but you have to be one hell of a shot to appreciate it (and you probably need to be benched, sandbagged and have a big ol' scope as well).
     
  9. Brian Williams

    Brian Williams Moderator Emeritus

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    They look nice, a little pricey, but nice.
     
  10. arthurcw

    arthurcw Member

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    Thanks guys.

    I'm trying to design a middy that is just a tad bit lighter for the Mrs. I'm going to show her all of this and see what she says.

    And no... I will not notice the difference in accuracy. But she might, she shoots better that I do. But I’m the cook, so she can’t lord it over me or she gets beans and rice.

    Seriously, as long as the 1/7 will handle defensive ammo like 55gr Hornady TAP and the like, I'm good with giving up the light weight varmint rounds. If we ever want a Varminter, we'll get a different upper.

    Thanks again.
     
  11. arthurcw

    arthurcw Member

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    gonna add this.

    If anyone has any other suggestions in this category, please offer them.

    Thanks.
     
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