338 Lapua Build - Barrel length

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by Kalashnikov, Oct 28, 2008.

  1. Kalashnikov

    Kalashnikov Well-Known Member

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    This may be splitting hairs, but I am getting hung up on 29" vs 28" barrel length (plus 2 " with brake) for the new barrel on my 700P 338 Lapua. The stock will likely be my A5. Is there will be a noticeable difference between the two lengths - if no, 28" may be better for me ? However...

    I want to maximize the 'real' potential of the 338 Lapua at the range and in the field, and want this to be a dedicated LR rig. This will not be a multi-purpose rifle, and I intend it for shots at 800-2000 yards +. The area I will use it in is windy, wide open prairie and the river breaks in southern, Aberta and huge, open fields in the north. I will likely hike at most 10 km, and more realistically ride in on my mountain bike followed by short 1-2 km hikes, but I do like to hike. I want the rifle to be manageable and portable, and 29" (31" length with brake) is as long as I want to go. I like the flat trajectory of the 250 grain SMK's and 250 Accubonds, but will likely end up shooting 300 SMK's exclusively.

    The barrel I have will go just over 29" finished length (31" with brake). I really want to extract as much as I can with this 338 Lapua, and want the most out of it if it will make a 'real' difference. Does the extra velocity of the 29" mean anything over the 28" ?

    However, the 28" barrel (30" with brake) is certainly tempting 'cause it will be [slightly] stiffer, handier, and easier to find a gun case for.

    Would it make any difference if I went 29" vs 28"? I am seeking advise on the barrel length for my intended use - the last detail for the build. Thanks
     
    Last edited: Oct 29, 2008
  2. amu_shooter

    amu_shooter Active Member

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    I faced the same problem recently. My original barrel was 34" w/o a brake and wanted something a little lighter.

    I ended up with a 28" plus a brake. Still managed 2910fps with a 300SMK.

    Final load is 108.5gr of US 869 with 215GM primer, Lapua brass and the 300SMK with a 4.100 OAL.
     

  3. Kalashnikov

    Kalashnikov Well-Known Member

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    4.1 AOL - what action/bottom metal are you using. Sounds like very good velocity.

    The 28" has it's appeal, but so does a longer tube.
     
  4. amu_shooter

    amu_shooter Active Member

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    SAKO -TRG with factory magazine. I have to short seat rounds to 3.750 if I need the mag for hunting but the chamber is cut for the 4.100. Majority of time I shoot singles so it not a big deal.

    Doesn't seem to effect group size much at short to moderate range.
     
  5. Kalashnikov

    Kalashnikov Well-Known Member

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    For those who have run/are running 28" barrels with any of the big 338's, what performance/velocity are you getting ? Thanks
     
  6. ol mike

    ol mike Well-Known Member

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    25-30fps difference in 1" of barrel length.
     
  7. davewilson

    davewilson Well-Known Member

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    i can assure you the ability to kill at the distances you mention, will be no different with a 28 than it will be with a 29. go to Lilja's web site and look at the velocity differences he obtained starting with a 46" barrel then cutting off 2" at a time and chrono'd the velocity of each barrel length. the difference between a 44" barrel and a 24" was only 232 fps. you might gain 15fps with a 29 over a 28.
     
  8. Kalashnikov

    Kalashnikov Well-Known Member

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    Yes, I have read and reread Dan Lilja article on 338 Barrel length, and have scoured every thread I can find on LRH, and feel confident the difference in FPS is negligible. Then, after measuring, and remeasuring, and remeasuring, etc. my drag bag (and commonly available hard gun cases), various total length(s) of barrel plus muzzle brake, and then rifle overall length(s), I have decided that 28" plus brake (for a 30" barrel OAL), and therefore a rifle OAL of 50.5" is the direction I will be going.

    Thanks for everyones input.