Rate of Twist for 308win

Discussion in 'The Basics, Starting Out' started by trebark, Aug 23, 2008.

  1. trebark

    trebark Well-Known Member

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    Today I had the opportunity to shoot a Rem700 in 308win. It was pretty sweet, shooting slightly less than 1moa right out of the box. The rate of twist on the barrel was 1:12.

    What's the bullet weight range for this rate of twist?
     
  2. ogre

    ogre Member

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  3. trebark

    trebark Well-Known Member

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    We were shooting factory-loaded Remington 180grain round-nose soft points in this particular 1:12 twist 308. I was impressed with its out-of-the-box accuracy.

    Given that my .280 is a 1:9 twist, I thought 1:12 for a 308 is fairly slow, so it would probably shoot lighter bullets better.

    So my question remains....what is the optimal weight range for a 12 twist 308?
     
  4. Varmint Hunter

    Varmint Hunter Well-Known Member

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    Delete double post.
     
    Last edited: Aug 24, 2008
  5. Varmint Hunter

    Varmint Hunter Well-Known Member

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    Many competitive shooters have said that a 12" twist (.308win) is all that is necessary to stabilize the 175gr SMK, which seems like the go-to bullet for several disciplines. However, you will occasionally find a 12" twist that won't work well with the 175's.

    I think you should be fine with any bullet up to that weight/length.
     
  6. ogre

    ogre Member

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    Whatever your testing tells you it is, and whatever your goal's are. Every rifle, and every bullet will be different, and one person's/brand's load of a certain grain bullet will be different than another. Rem has been using 1:12, with little to no complaints, and Savage has been using 1:10 with little to no complaints.
     
  7. Guy M

    Guy M Well-Known Member

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    The 1:12 twist works great with the 168 grain bullets from Sierra & Nosler. That's where I'd start, looking for accuracy with a 1:12. That twist often though will also handle a 175 SMK well.

    Classic "Palma" loads use a 155 gr bullet and a 1:13 twist.
     
  8. shadowdrak

    shadowdrak Active Member

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    In my Rem 700 .308 with a 1:12 twist, I can handle 165, 168, 178, and 180 g. bullet weights with sub-moa accuracy. I tried 150's the other day and they were grouping over 1 moa on me, so I know my barrel doesn't like the light-weights. I haven't tried 110 V-maxs, but that is just too light of a bullet for me to be using with that twist. Bench rest guy I know is using a 1:18 twist for a 30BR and he's getting around sub-moa. Each particular rifle is picky.
     
  9. JOSE A. MARINE

    JOSE A. MARINE Well-Known Member

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    My shilen select match with a 12 twist works awesome with 150 and 155 noslers... better than half moa anyday. (I dont use heavier bullets because 150 gr. is more than enough for silhouettes.)

    Joe from Old Mexico.
     
  10. Michael Eichele

    Michael Eichele Well-Known Member

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    The 1-12 twist will work well with 150's up to the 190 SMK. A sweet spot for the 12 twist at 308 velocities is the 178 AMAX and 180 SMK. The original green hill formulas put the 12 twist at the 168. Modern twist calcs show a bigger bullet such as the 178-180. Shoot em all and settle on the best one for YOUR barrel.
     
  11. GSoD

    GSoD Well-Known Member

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    For target shooting I got 175grain SMKs to pattern between .7-.3" depending on me.

    For hunting I got 168 Barnes XXX to park at about .5"

    The 180grain stuff I have yet to get to work out of my 1:12 Rem700P.

    Haven't tried any of the smaller stuff as I've gotten these to work really well.
     
  12. edge

    edge Well-Known Member

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    Last edited: Sep 12, 2008
  13. trebark

    trebark Well-Known Member

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    Thanks for all the info everybody! Keep it comin'!
     
  14. jmj

    jmj Member

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    Years ago in competitive benchrest the "standard" twist rate for a 308 shooting the 168 grain matchking was 1 in 14. That was considered the ragged edge. Some had success using the 1 in 15 but most didn't. Those shooting the 180 grain were using the 1 in 12. I never heard of anyone having any accuracy problems using 180 grain matchkings from a 1 in 12 twist but that can also be considered to be the ragged edge of stability/accuracy. Just keep in mind that all barrels were stainless steel and stress relieved. Shilen barrels currently recommends a 1 in 12 twist rate for 170 grains or less.