Help outside neck diameter

Discussion in 'Reloading' started by Jinx-), Oct 4, 2009.

  1. Jinx-)

    Jinx-) Well-Known Member

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    Aug 23, 2009
    Got my Forster original outside neck turner attachment 4 days ago, in the manual which came with it, for .308 Winchester cases SAAMI has .3435" outside neck diameter. I measured necks on the brass fired and its measures 0.346" my question: according to SAMI .308 should have max .3435" outside neck diameter, so if my fired cases coming out 0.346" does this considered to be none-standard chamber? Should I in the future trim my necks to 0.346" - 0.344"? When I neck size previously fired brass neck diameter of those with the bullet seated is 0.334" so it looks like +0.012" difference between them.
    Thanks for any suggestion…
     
  2. woods

    woods Well-Known Member

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    Jun 4, 2006
    You have .012" neck clearance around your loaded round. That is larger than usual.

    You have brass neck thickness of .013" which is normal but a little on the low side.

    You do not need to neck turn but might want to in order to make your neck thickness more consistant for better bullet release and runout.
     

  3. Jinx-)

    Jinx-) Well-Known Member

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    Aug 23, 2009
    Thank you
     
    Last edited: Oct 5, 2009