.338 Edge from 7mmRUM brass?

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by Hicks, Jan 16, 2011.

  1. Hicks

    Hicks Well-Known Member

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    For those of you who have one, is it possible to form .338-.300 brass from 7mmRUM brass? I've got about 200 pieces and I'd sure hate to waste them.

    Hicks
     
  2. geargrinder

    geargrinder Well-Known Member

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    You can, but your necks will be very thin. You're likely to split more than a few.
     

  3. davewilson

    davewilson Well-Known Member

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    yeah it can be done. i did exactly that making a couple dummy rounds for guys. i'd push it out in at least 2 steps, 3 would be better. then check your OAL, concentricity and wall thickness of your necks. the neck thickness doesn't change that much.
     
  4. Michael Eichele

    Michael Eichele Well-Known Member

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    I have heard it said that if up sizing 2 calibers that the necks should be anealed after necking up.

    I also agree that these should be sized in at least 2 stages. First 30 cal then 338.
     
  5. Hicks

    Hicks Well-Known Member

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    What kind of trouble would I get into if i just fire formed them?
     
  6. geargrinder

    geargrinder Well-Known Member

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    You need to expand the necks. Fire forming won't do it.