Bullet Variation

Discussion in 'Reloading' started by mtang45, Jan 16, 2011.

  1. mtang45

    mtang45 Well-Known Member

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    Apr 9, 2005
    I'm working on a 7mm STW load for 180gr VLD Bergers and am trying to sort to eliminate as much variation as possible. I've sorted by weight, and right now I'm sorting again by the length of the bearing surface. What other dimesions should I consider measuring? Total length? Base to ogive? Nose to ogive? Or other? A person could go crazy sorting out all the possible variables.

    By the way the range I'm getting is .12mm total variation on the bearing surface, and .4gr total variation on the bullet weights. Does this sound excessive, normal or good?
     
  2. mtang45

    mtang45 Well-Known Member

    Messages:
    249
    Joined:
    Apr 9, 2005

    Just a followup. I measured all 100 bullets in the box and found the bearing surface to vary from 16.25mm to 15.91mm. Weight was fairly consistant and varied from 179.6gr to 180.1gr.

    The majority of the bullets fell into three groups 16.2mm +- .02, 16.15mm +- .02, 16.10mm +- .02. I did have three greater than 16.22 and 5 less than 16.08.

    Most bullet weights fell within 180gr +- .1 with about 10 weighing less than 179.9, none were over.

    This is the first time I have checked Berger bullets, is this normal variation?