Twist Rate?

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by theEMP, Jun 8, 2014.

  1. theEMP

    theEMP Well-Known Member

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    Just about to pull the trigger and order a new barrel. Going to chamber in 7mm rem mag. I want to shoot the 180 Berger VLDs. Should I go with a 8 or 9 twist? Most recommend 9 but is 8 going to be better. I don't want to be on the edge of stability. Thanks.
     
  2. 7magcreedmoor

    7magcreedmoor Well-Known Member

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    I run 180 VLDs in a PacNor 3 groove with a 9 twist, been great so far. My home state ranges are all less than 1200 ft above sea level, no stability problems. 7rem mag running 2905 avg muzzle velocity, 2.2 inches at 300 yards for the first three shots out of cold bore. It does get looser when hot if I shoot fast. I ordered another barrel with the same specs but a heavier contour for my next project in 280 AI, the 7mag barrel is factory contour (pretty skinny- .5ish at 26 inches) and that is my one regret concerning that barrel.
     

  3. J E Custom

    J E Custom Well-Known Member

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    The 8 twist might be a little better, but it would be to much if your rifle did not like the 180s and you have to shoot 168s.

    I shoot a 1 in 9 in both the 7mm RM and the 280 AI and they are extremely accurate @ 1000 yards.

    The 1 in 8 may have bullet engraving issues if pushed hard.

    Just my opinion

    J E CUSTOM
     
  4. AZShooter

    AZShooter Well-Known Member

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    If you went with a 1 in 8.5 your rig would be ready to shoot the upcoming (eventually) 195 Berger.

    From an old post:

    195 Berger EOL Hybrid projected BC of .794 (G1) .406 (G7) 1 in 8.5 twist
     
  5. fmajor

    fmajor Well-Known Member

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    What grain wgts are you shooting that work well in your 1-9 barrels?

    It sure seems a difficult balance to achieve if a hunter wanted to go after, say, antelope using 140's or 160's and then elk using 180's or even 190/195's out of the same gun.
     
    Last edited: Jun 9, 2014
  6. theEMP

    theEMP Well-Known Member

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    Thanks everyone. I will probably go with the 1:9 just to keep the options of shooting lighter bullets. Midway had a 1:8 twist in stock so I wouldn't have to wait so long.
     
  7. J E Custom

    J E Custom Well-Known Member

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    The 1 in 9 worked well with all bullets.

    I used the 168 SMK for the 1000 yard matches and all others for hunting

    This rifle was a 7mm Rem Mag also, and with the velocities possible in the 1 in 9 It was a 1/4
    MOA rifle at 600 and 1000 yards.

    I also had a 1 in 9.250 that did well with all bullets tested. (It was my hunting rifle and I shot 140s
    for dear size animals and 160 to 180s on Elk and never lost a one.

    Now that I have used the Accubonds a lot I would have confidence in the 160 Accubonds on Elk
    out to 500 or 600 yards And would have no problems using the 160 Accubond load for everything
    if it shot good.

    Just my opinion

    J E CUSTOM
     
  8. fmajor

    fmajor Well-Known Member

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    Gold. Pure gold.

    Thanks!!!