7mm twist rate?

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by Timberbeast7, Dec 19, 2007.

  1. Timberbeast7

    Timberbeast7 Well-Known Member

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    I'm going to have a 7mm WSM built for long range hunting and need advice on barrel twist rate. I plan on shooting 160 AB's, or 162 a-max but would like the option to go up to 180 bergers. Would a 1:9" twist work for both? (Berger recommends 1:9" for 180 gr. and 1:10" for 168 gr. whereas most of the barrel manufacturers recommend 1:9" for anything over 140 gr.) Any ideas? Thanks
     
  2. Mikecr

    Mikecr Well-Known Member

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    You already have your answer: 1:9
    That's the right twist..
    What kind of ideas are you looking for?
     

  3. Timberbeast7

    Timberbeast7 Well-Known Member

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    I guess just verification that a 1:9" would not be too fast for the 160 gr bullets. Or has anybody used 1:9.5" or conversely 1:8.5"? Just checking if anybody had any other alternatives/ideas.
     
  4. eddybo

    eddybo Well-Known Member

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    I would build on a long action if you intend to shoot the 180s and have it function as a repeater. Mine shots the 180s into 1/2MOA with a 9 twist. Only problem is I have to load them very deep so they fit in the magazine. Everything is just a little jammed up and would IMO just work better on a LA. I dont even want to know how well this thing would shoot if I could reach the lands. I will not even try it because I know I will end up loading them long and shooting single shot.
     
  5. Timberbeast7

    Timberbeast7 Well-Known Member

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    I've got a Rem 700 300 SAUM that I'm getting the action from and plan on using a Wyatt's box mag., so this should take care of bullet seating depth issues.
     
  6. davewilson

    davewilson Well-Known Member

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    9 would be the right twist. those 180 Berger's are a long bullet. i'm also in favor of the long action.
     
  7. tjonh2001

    tjonh2001 Well-Known Member

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    i just got my 7mm wsm built.i am shooting the 168 bergers but have tried 180s. there is no question that you have to go with a long action. then you will need to get the hs bottom metal in 300 wm. this is a great combination.
     
  8. Timberbeast7

    Timberbeast7 Well-Known Member

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    What kind of overall cartridge lengths are you getting with the bergers and the 160 gr. accubonds.