6.5 STW barrel

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by midwesthunter, Dec 28, 2011.

  1. midwesthunter

    midwesthunter Well-Known Member

    Messages:
    846
    Joined:
    Feb 28, 2008
    Will be having one made very soon and looking for info on what twist I should use? Plan on shooting 140-142 grain bullets.
     
  2. Loner

    Loner Well-Known Member

    Messages:
    599
    Joined:
    Apr 14, 2010
    An 8 should do it for most.
     

  3. Outlaw6.0

    Outlaw6.0 Well-Known Member

    Messages:
    3,006
    Joined:
    Feb 18, 2010
    A 1-8" will definitely do it, look around for a stability calculator. With the velocity potential I wouldn't be surprised if a 1-8.5" or even a 1-9" wouldn't work (better).

    I just bought a 1-8.4" Obermeyer for my 6.5WSM.

    No, I don't know why he made them 8.4 :D
     
  4. outofayr

    outofayr Well-Known Member

    Messages:
    185
    Joined:
    Nov 20, 2008
    I have a 1-8.5" on my 6.5-06AI and it stabilizes 140 AMaxes easily, even at the low accuracy node ca. 2650 fps. With your velocity, I'd think a 1-9" twist would work fine, and a 1-8" won't hurt anything...

    Have fun,

    Brian
     
  5. Outlaw6.0

    Outlaw6.0 Well-Known Member

    Messages:
    3,006
    Joined:
    Feb 18, 2010
    You might seriously consider the slower twist, after you get some rough spots in the throat you could start dusting the light jacketed bullets like the Berger Hunting VLD. (if you plan to use them), if not the CEB's & SMK's will hold up to a 1-8" just fine, I don't know about the A-Max.
     
  6. Loner

    Loner Well-Known Member

    Messages:
    599
    Joined:
    Apr 14, 2010
    Berger recommends an eight for their 140's.
     
  7. Outlaw6.0

    Outlaw6.0 Well-Known Member

    Messages:
    3,006
    Joined:
    Feb 18, 2010

    With the Target VLD's there won't be any problems & there probably won't be with the Hunting VLD's for the first couple hundred rounds.... a 5R bbl would help too.

    I'm not saying that it won't work, I just trying to point out what could (& has) happen. At the velocity of the STW, the Hunting VLD are going to spinning VERY quickly, with a rough throat, tight twist & high velocity bullet separation is a real possibility.

    I would enthusiastically recommend the 1-8" for a 260(ai) or 6.5 CM or anything under the 264WM... but in this case a 1-8.5 or 9 may be better.
     
  8. midwesthunter

    midwesthunter Well-Known Member

    Messages:
    846
    Joined:
    Feb 28, 2008
    I was thinking with the velocity I will be getting a 1-9 would work.
     
  9. Long Time Long Ranger

    Long Time Long Ranger Well-Known Member

    Messages:
    2,612
    Joined:
    Mar 12, 2002
    I have a 1-9 twist 6.5 STW and it stabilizes the 140's well. It is a fun gun to shoot with the 140's around 3400 fps. Check the ballistics of a .612 or whatever bc at 3400 fps and you see why I like it so much. It is a very accurate cartridge. I had a good friend that shot a 6.5-300 wby years ago but I went with the STW because of the cheap brass. Same performance and both fun to shoot.
     
  10. midwesthunter

    midwesthunter Well-Known Member

    Messages:
    846
    Joined:
    Feb 28, 2008
    Brass will be a lot easier to form also over 300wby