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Which twist 1:7 or 1:8?

Discussion in 'Black Rifle Forum' started by jdavionic, Feb 20, 2010.

  1. jdavionic

    jdavionic NRA Member

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    I am building another AR and have decided to go all out with trying to make it as accurate for longer distance shooting as I can get it (or at least as accurate as I can afford).

    I've been looking at White Oak barrels.
    http://www.whiteoakarmament.com/

    They seem to be decent quality, although I'd certainly welcome opinions on them...or recommendations for better barrels.

    But where I'm stumped is on deciding which twist - 1:7 or 1:8. I know these ratios are both good for shooting heavier rounds. My thought is that 1:7 will have slightly better results than 1:8 since it will offer just a little better stability for the bullets in flight.

    Your thoughts? Barrel mfg opinions?
     
  2. faawrenchbndr

    faawrenchbndr DirtyThirty fan CLM

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    1 in 7 is better for stabilizing hearier rounds. White Oak barrels are very good.
     

  3. javelinadave

    javelinadave Hebrew Hammer

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    Is that Japanese for heavier?:supergrin:
     
  4. jdavionic

    jdavionic NRA Member

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    Thank you! I expect it will take some time before I get all of the pieces that I've picked out which so far are...

    Geissele Match Rifle trigger

    Magpul PRS stock

    WOA Barrel & matching bolt...specifics TBD depending upon some more research. But I've heard good things about their barrels, including your feedback.

    Upper - Not sure on the upper yet. I'm thinking of the Vltor or LaRue. This is somewhat depending on the barrel choice (e.g., M4 feedramps)

    Lower - I went with RRA, since I have one. Hopefully it will be fine. I can't imagine that it will be an issue.

    Handguard - LaRue Tactical 12.0

    Scope - TBD. All I know at this point is that my taste far exceeds my wallet. However, I will not skimp on the glass. If I have to save for quite some time, then so be it.
     
    Last edited: Feb 20, 2010
  5. faawrenchbndr

    faawrenchbndr DirtyThirty fan CLM

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    Nope,.....just means my old azz can't type worth a pizz! :rofl:
     
  6. faawrenchbndr

    faawrenchbndr DirtyThirty fan CLM

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    :supergrin:
     
  7. jdavionic

    jdavionic NRA Member

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    Thanks! For scopes, I've been mainly focused on the Leupold scopes. I've been reading about others like the Burris XTR, Valdada IOR, etc. But Leupold has an excellent reputation.
     
  8. USMC03

    USMC03

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    1/7" vs 1/8" ...... Read the info I wrote in this post:

    http://www.m4carbine.net/showthread.php?t=29302



    1/8" twist is a more versatile twist and will shoot a wider range of bullets. About the heaviest bullet being used in an AR is an 80 grain, and due to the length the 80's won't fit in a magazine and have to be fed by hand. Both 1/7" and 1/8" will handle the 80's very well. As AR shooters, the heaviest round we commonly use are 77 grain bullets. Both Both 1/7" and 1/8" handle the 77's very well.

    So both have the heavier bullets covered. Remember slower twist rates for lighter bullets and faster twist rates for heavier rounds. With the 1/8" being a little slower, it will handle some lighter rounds that the 1/7" may have problems with. Both the 1/7" and 1/8" shoot 55 - 77 grain bullets well.


    In my opinion, the 1/8" twist is the best compromise in barrel twist between the 1/7, 1/8, and 1/9 for most civilian and law enforcement shooters when you consider the bullet weights most of us are shooting.
     
  9. jdavionic

    jdavionic NRA Member

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    Thanks! I've never ventured into that site. I read your post and it was very informative. The pics on the match were interesting as well.
     
  10. Mike5560

    Mike5560

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    I agree with USMC. I recently was researching the trade-offs between the two. For the longest time most AR manufacturers have been making mostly 1:7 or 1:9 twists. But recently on some newer models I've been seeing 1:8 spring up. I had to see the reason behind this.
    The heaviest most AR shooters will use is 77 grain. 1:7 and 1:8 twists will both stabilize these, but 1:8 will allow you more flexibility for some lighter varmint bullets.