Barrel question

Discussion in 'AR15/10 Rifles' started by STWdude, Oct 20, 2011.

  1. STWdude

    STWdude Member

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    I'm looking @ going with a JP-15 in .223. Their website states that the rifles come with a 1:8 twist barrel which they claim is an all around good twist for most any round.
    I'd like to shoot 55 gr ammo, and this seems to be a fast twist for 55's.
    Anyone shooting an AR with a 20" 1:8 barrel with 55 gr rounds that stack well?
     
  2. esorensen

    esorensen Well-Known Member

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    I shoot the 55 VAMX out of a Lilja 8 twist and they shoot 1/2 to 1/3 MOA.
     

  3. Kevin Thomas

    Kevin Thomas Well-Known Member

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    A 1x8" is fast enough to shoot 77s, 80s and 82s, no problem at all. It's a lot faster than you need for 55s. Thing is, there's really no such thing a "overstabilzation." A bullet is either stable, or it isn't. In this combination, the lighter bullets will have a much higher stability factor, but if they're good bullets, they should still shoot quite well. The one issue with a faster than needed twist is bullets of very poor quality. The excess twist will accentuate any jacket concentricity problems or center of gravity flaws in those bullets and that will open up the groups. The solution there is not to use crappy bullets, plain as that.
     
  4. msalm

    msalm Well-Known Member

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    As stated already, normally the 1-7 to 1-9 twist barrels will shoot the lighter bullets very well. I wouldn't hesitate to use 1-8 on 50-55gr bullets. No problem shooting 1/2 MOA or better with the lighter pills in a good barrel.
     
  5. STWdude

    STWdude Member

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    Thanks for the replies gentlemen. Ya'll have been most helpful.