178 Grain amax out of 308, 1:12 twist

Discussion in 'The Basics, Starting Out' started by xAsylum, Oct 10, 2011.

  1. xAsylum

    xAsylum Member

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    I'm thinking about making a load of 178 amax's for my Remington 700 sps tactical. Can the 1:12 twist handle this bullet?
     
  2. BountyHunter

    BountyHunter Writers Guild

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    Yes, quite easily in the 308

    BH
     

  3. The Surgeon

    The Surgeon Well-Known Member

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    At what range?

    Keep in mind, I have no data to prove this, just hear say.

    I have spoke with several barrel manufacturers about this very issue. Over half of them recommended a faster twist to stabilize anything higher than 168. According to them, the 1:12 was good up to the 168gr for ranges greater than 500 yards.

    This is what I have been told. Do what I did and call up some barrel mfg. It only takes a few minutes and most are pleased to help someone out.
    I'm fairly sure that Krieger got quite tired of me calling and bugging them about my first build. I figured, who better to get my info from than those that
    make their living by such products i.e. rifle barrels.

    I run a Krieger with a 1:10 on a Surgeon 308.

    I have another Rem 700/Krieger chambered in a 308 that has a 1:10 and it groups well past 500.
    Some folks will scoff at a 1:10 twist on a 308, but I have several paper targets that would argue that it is just fine. I shoot Berger 175gr BT LR T's and 155.5gr Match Fullbores.

    Again, I am just passing along information that was given to me by other manufacturers.
     
    Last edited: Oct 11, 2011
  4. bowhunthard

    bowhunthard Well-Known Member

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    I have the 700 VTR (1:12" twist, 22" barrel including brake, so about 20.5"). The 168gr. bullets shoot great to 750 yds. for me, the 178gr. bullets shot ok until about 250 yds. Then at 450 yds. I was getting about 8" groups (unacceptable!). My 750 yd. groups with the 168gr. are about 2.5 - 3" on a windless day lol.

    In my experience, the 178gr. is too heavy out of a 20" 1:12" twist barrel for long range shooting (I was only getting about 2450 fps out of my barrel with the 178gr.). You need either more velocity or a faster twist (basically a longer barrel or faster twist). 168gr. is the "perfect" bullet weight for a standard .308 Win.

    Good luck.

    P.S. Remember this is an opinion based on personal experience, not necessarily a fact written in stone lol :).
     
  5. BountyHunter

    BountyHunter Writers Guild

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    Most FTR guys are using the 11 or 11.25 twist, with a few at 10 or 12, and the dominant bullet being the Berger 185. They are running them with the longer barrels (30") to 2850.

    You need to run the 178 to around 2650 which is quite easy to achieve in most guns. Otherwise, they can be unstable at longer ranges.

    The 168 will to 900 yards and then it starts tumbling. So most people do not bother with the 168 for LR. Shorter ranges it is OK.
     
  6. bowhunthard

    bowhunthard Well-Known Member

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    Would this be any 168 in general? Or primarily the 168 gr. SMK? I've heard bad things about the 168 SMK when it nears the transonic stage. The furthest I've shot the 168s is 750 yds. so far...
     
  7. BountyHunter

    BountyHunter Writers Guild

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    The 168 SMK.

    See. Too many tumbling thru the target at 1K