Twist Rate

Discussion in 'Rifle Talk' started by midwayman1, Sep 20, 2004.

  1. midwayman1

    midwayman1 Member

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    I am looking for a good idea of proper twist rate. From what I understand, the heavier the bullet, the faster the twist rate you need. I assume that a 1:10" twist is faster than a 1:12". I shoot a standard M77 ruger in 30-06, and the advertised twist rate is 1:10". So would I be better off shooting a 150g or a 180g bullet? which would be more accurate? or is it enough to even worry about?? thanks in advanced.
     
  2. wwb

    wwb Super Member

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    The ideal bullet for a 1:10 in .30 cal is about 165-170 gr at a muzzle velocity of 2900-3000 fps. Heavier (longer) bullets need a faster spin to be stable... but there's a double whammy: heavier bullets have lower muzzle velocities (SAAMI pressure limits, you know), so the twist rate must be even faster to get the desired spin rate.

    In your case, 150, 165, or 180 grain bullets will be okay. Do a little experimentation at the range, find a load that your rifle really works well with, and stick with it for everything.

    200 or 220 grain bullets in a .30 cal would need a really fast twist in order to be stable and accurate. They are usually used on big animals at close range, where MOA accuracy doesn't matter.