Can a 338 lapua mag

Discussion in 'Long Range Hunting & Shooting' started by Southernfryedyankee, Jun 13, 2009.

  1. Southernfryedyankee

    Southernfryedyankee Well-Known Member

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    Be built on a Weatherby Vanguard 300 weatherby magnum action?
     
  2. J E Custom

    J E Custom Well-Known Member

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    Not very well.

    It's the bolt face issue again. The vanguard bolt is small and does not leave much of a extractor
    when opened up.

    It will work with a 338 RUM or a 300/338 rum with out opening the bolt face.

    The Weatherby MK5 would be my choice to open up and with the extra magazine length it
    allows the use of 250gr and 300gr bullets to be loaded longer increasing powder capacity.

    I have the 338 RUM on a MK5 action and the COAL is 3.750 with room to spare in the magazine.
    (The Factory COAL is3.635 for the 338 RUM). 0.115 longer in the MK5.

    J E CUSTOM
     

  3. Tyler Kemp

    Tyler Kemp SPONSOR

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    I have a Mark V 300 Weatherby that would be a perfect donor gun for you! I want to sell it to fund a custom action for my 338 Lapua build.
     
  4. Boss Hoss

    Boss Hoss Well-Known Member

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    I have a 338 Lapua Improved on a Mark 5 that was built by Speedy (had to make him do it as he hates to work on those) with a Tim North barrel that I thought I needed. All accuracy work has been done and shoots outstanding however I have only shot it 30 times so it needs to be developed more. Have 3 others now built on the new Stiller, BAT and a Python. Could be talked out of it but you would have to get dies made.
     
  5. PEI Rob

    PEI Rob Well-Known Member

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    What are the measurements of the MK5 bolt? Body diam, head diam at outside of lugs, lug height, lug width? Any pics? Reason I ask is because this comes up often and I don't have one.
     
  6. J E Custom

    J E Custom Well-Known Member

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    Rob.

    I don't have them all but I will give you the dimensions I have.

    Weatherby MK5 bolt dimensions =

    Bolt body = 0.845 outside diameter.
    Lug O.D. = 0.845 with 9 lugs.
    Bolt face O.D. = 0.716 avg.
    Bolt face I.D. = 0.537 standard magnum.
    Bolt face I.D. = 0.585 378 based cases.
    Magazine length = 3.800"

    As you can see with a bolt face outside diameter. of .0716, you can open it to .0585 or even
    .0610 with out removing the shroud.

    I hope this helps

    J E CUSTOM
     
    Last edited: Jun 16, 2009
  7. 358sta

    358sta Well-Known Member

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    J E Custom - Are your decimals in the wrong place - .0845" vs 0.845"? I figure they are. Just wanted confirmation.
     
  8. Fiftydriver

    Fiftydriver <strong>Official LRH Sponsor</strong>

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    It is possible but as mentioned, it would likely be wiser to just go with the 338 Edge which is basically identical in performance to the Lapua but would work in the bolt face with no modifications needed there.

    The Vanguard is a strong receiver and could likely handle anything that the Rem 700 could but it is not nearly as easy to convert as the Rem 700.
     
  9. J E Custom

    J E Custom Well-Known Member

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    Yes they are. sorry I should have proofed it before I posted.

    J E CUSTOM
     
  10. Long Time Long Ranger

    Long Time Long Ranger Well-Known Member

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    I wouldn't do the lapua on the vanguard/howa action. I have done easily over fifty ultramags, probably over fifty 338-300 ultramags off this action. It is a very strong action for the ultramag but requires more work for proper feeding than the 700 action.
     
  11. PEI Rob

    PEI Rob Well-Known Member

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    Thanks J E Custom. I have looked at a few but never had the chance to work on or inspect one.
    Interesting lug contact area. With 3 lugs in one diamter and a few thou clearance, each lug is what, .44" long ? and .062" into the action [clearances reduce the actual contact area]. This would give .240" total lug contact area, that's a LOT of contact area, well over 2.5X that of a Rem. I'm not going to run out and buy one or anything but its interesting nontheless.

    Cheers,
    Rob