Building 6mmAI, how long of a barrel?

Discussion in 'Long Range Hunting & Shooting' started by Cramer06, Feb 28, 2013.

  1. Cramer06

    Cramer06 Member

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    My new project is a 6mm ackely improved on a savage action. I'm thinking of a 1/9 twist for bullets in the 100gr range. Probably a mcgowan varmint contour barrel with a muzzle brake. The one thing I'm having trouble deciding on is barrel length? How long do I really need? Weight is not a huge issue, but I don't mind having a shorter barrel if I can get away with it.
     
  2. redgun

    redgun Well-Known Member

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    I would sugget you go 1-8" twist. Barrel length just depends on what you plan to do with it. 22"-26" for hunting, but can go a little longer if strictly a target gun.
     

  3. Cramer06

    Cramer06 Member

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    1/8 twist is also an option. I prefer to go shorter since it will see quite a bit of hunting time. I just want to be long enough to not hinder performance. I just put a .204 together and a lot of guys swear if it was less than 26" you aren't burning all your powder. Whether that is true or not, I can't say. I haven't heard a common number to go with the the 6mmAI.
     
  4. redgun

    redgun Well-Known Member

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    I shoot heavy VLD's out of all my guns. A 6mmAI just beg's for the 105 (or even the 115) VLD, assuming you plan to do some longer range shooting. The 1/8 twist is the general favorite for this weight range.

    Barrel length is a personal preference. A longer barrel will get you more velocity, but might not be the best option for a "hunting" gun. Your style of hunting will dictate what is best for you.:)
     
  5. Terry Scott

    Terry Scott Well-Known Member

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    Have a 243 Ai and a 6.5 AI both with 26 inch barrels. With the "AI" you are usually tring to maximize velocity within reason. 26 inches seems to be a good useful middleground for these rifles.
     
  6. Cramer06

    Cramer06 Member

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    I can live with that. The new .204ruger is a 26'' and I can handle it. I'll just have to man up when I take it calling for yotes. I'll look like Arnold by the end of the day.
     
  7. WildRose

    WildRose Well-Known Member

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    I'd say with a 24" bbl you'll get all the good out of your 6mm AI and have a nice practical hunting length rifle.

    As for the .204, my little 20" is certainly getting good powder burn efficiency since it has very little muzzle flash in low light. It just doesn't take much barrel to burn 30-32gr of powder.
     
  8. Terry Scott

    Terry Scott Well-Known Member

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    If weight is a concern just flute the barrel
    Or a thinner contour or both.
     
  9. AZShooter

    AZShooter Well-Known Member

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    If you want to use most of the 100-107 gr bullets you will need a 1 in 8 twist. As for length for a 6mmAI I'd opt for 28". I have a 28" 257 weatherby and that barrel added velocity without being too long for me. Get the barrel long, you can always cut some off and recrown if you find it objectionable.
     
  10. Cramer06

    Cramer06 Member

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    Weight isn't really a concern. I have lighter guns if I need them, but I'm also not TRYING to build the heaviest gun I can haha. If a 22'' gun will shoot the same as a 26'' gun, then I have no problem reducing the length and weight of the barrel.