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"Crowning"

Discussion in 'Gunsmithing' started by gkdir, Jan 21, 2010.

  1. gkdir

    gkdir

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    OK- so what does "crowning" do for the barrel. I know what it is, I just don't fully understand why.
     
  2. hi-power man

    hi-power man Silver Member

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    Bart Bobbitt's comments:

    "The accuracy of the crown means the land and groove part of the
    barrel must let the bullet's base exit evenly all the way around. When
    this happens, gas escapes uniformly and evenly around the bullet's base.
    If gas escapes unevenly (poor crown, even unsquare bullet bases), the
    point of greatest gas release will push the bullet in the opposite
    direction and tilt it. Tilted bullets leaving the barrel just don't
    shoot straight; how far they move sideways depends on their velocity,
    spin rate, and degree of tilt (or yaw, as it's sometimes called)."
     

  3. gkdir

    gkdir

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    Thank you--can't get much simpler than that.