6.5 stw barrel twist and contour

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by buckdeer, Nov 5, 2004.

  1. buckdeer

    buckdeer Active Member

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    Oct 24, 2003
    i'm getting the final funds together to order my 700 rebarrelled by pac-nor to 6.5 stw. i would like to hear your opinions on barrel twist and contour. my plans are for this to be a sporter-weight carry gun 9-10 lbs max. i'm looking at shooting only 140 grain bullets. here's the problems

    1. should i go with the 1-8 twist or 1-9 i'm thinking 1-8

    2. pac-nor makes a 3,4 or 5 groove barrel i'm thinking the 3 groove would give me better throat life.

    3. i what the barrel to be 28" should i go with the number 4 or 5 contours. in order to make my desired weight. i want the barrel to be stiff enough.

    what do you folks think most of you have much more experience at this than i do.
     
  2. Fiftydriver

    Fiftydriver <strong>Official LRH Sponsor</strong>

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    Buckdeer,

    1. The 6.5mm STW will perform best with a 1-9 twist with the bullets you want to use.

    I built myself a 1-9" 6.5-06 AI and it shoots the 140 gr A-Max bullets extremely well. You will have much more velocity then this round so the 1-9 wil probably even handle the 142 and 155 gr VLD bullets well also.

    2. I would go with the 3 groove. I use these on all of my customers rifles if it is my choice simply because bore fouling is reduced, velocity is slightly higher and throat life is substantially more then with a conventional rifling design.

    I would go with a #5 contour of the ones you list but if I had my choice I would go with a #6 as it will still weigh in under 10 lbs with the thicker barrel.

    My 30" #6 Lilja barreled rifles are shooting extremely well, often sveraging at or under 1 1/2" three shot groups at 500 yards with rounds of this class.

    Still at 28", the #5 should be fine with the 6.5mm bore.

    Good Shooting!!

    Kirby Allen(50)
     

  3. DANTEC

    DANTEC Well-Known Member

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    Jul 6, 2002
    6.5 STW is full pwder cartridge so under 30 inch you get big muzzle flash and loos in velocity , I use 31 in 6.5/300 ( 264 win mag body )

    top velocity 6.5 ( over 3000 fps in 139/142 ) are OK in 1 in 9 , 1 in 8 is only for "slow " 6.5 as 6.5x55 or 260 REM

    good shooting

    DAN TEC
     
  4. buckdeer

    buckdeer Active Member

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    Oct 24, 2003
    thanks for the responses

    the only reason i didn't really consider the #6 contour was that i do alot for offhand shooting and i didn't want the gun to be really barrel heavy thanks again
     
  5. DANTEC

    DANTEC Well-Known Member

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    Jul 6, 2002
    if your a bareel with stress releave and if you carefully bed your action to avoid vibration you can use a thinner barrel profile one nice and efficient is the palma contour ( light palma , you just need to order a Palma with longer cylindrical aera around the chamber to fit enought steel arounf the chamber )

    good shooting

    DAN TEC