reforming 338 Lapua

Discussion in 'Reloading' started by runningw, Jul 9, 2008.

  1. runningw

    runningw New Member

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    Do any of you guys have any experience or advise on reforming 338 Lapua to 7mm Rem mag? Headspacing is off the shoulder

    Thanks
     
  2. KRP

    KRP Well-Known Member

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    Somewhere in this process you are going to have to shrink the case head ~.050" and swage a belt onto it. Can't be done, if you try it I would like to hear the details.
     

  3. runningw

    runningw New Member

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    When the cartridge is headspaced on the shoulder no belt is necessary.
     
  4. BHP9

    BHP9 Well-Known Member

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    What KRP is saying - it can't be done.

    The case head diameters are 2 different sizes.

    0.588" for the .338LM. The parent case is the .416 Rigby.

    0.532" for the 7mm Rem Mag. This was a propriatary case from Remington.

    Also the .338LM is a beltless case.
     
  5. KRP

    KRP Well-Known Member

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    The 7 RemMag has a belt, regardless of whether you headspace off the shoulder the case has a belt and the chamber is cut for a belt.
     
  6. runningw

    runningw New Member

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    I did not come up with this idea, I read a semi-detailed description of the process some months on one of the reloading forums and can't find it now. I was just trying to see if anyone else had done this.
     
  7. BHP9

    BHP9 Well-Known Member

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    Could it have been a 7mm-338LM?

    In other words a.338LM necked down to 7mm. The .338LM has also been necked down to.30 cal.
     
  8. ss7mm

    ss7mm Writers Guild

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    [​IMG]

    [​IMG]

    Neck the 338 Lapua down to 7mm and you have the center round below. Blow that round out to the Allen Magnum configuration and you have the rounds on each side. Try to size the 338 Lapua down to 7mm RM and you will be bitterly disappointed. Check the case dimensions in the photos above.

    [​IMG]
     
  9. runningw

    runningw New Member

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    By the time I got around to checking case deminsions, I could not locate the info I found. When I compared deminsions I couldn't see how it would work either. I thought I would ask and maybe find answers from some that knows more about reforming than I do.

    Thanks all for the input.