Need terminology help

Discussion in '6PPC, 6-6.5x47, 6XC, 6 Rem, 243' started by Mikemci, Sep 27, 2017.

  1. Mikemci

    Mikemci

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    "7.5 ogive for .050" freebore"
    I was looking at loading data and that was written under "comments".
    What the heck is he saying?
    Thanks, Mike
     
  2. Sniper338

    Sniper338 Silver $$ Contributor

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    Edit - see below..
     
    Last edited: Sep 27, 2017
  3. Toby Bradshaw

    Toby Bradshaw Gold $$ Contributor

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    Understanding ogive types (tanget, secant, hybrid) and numbers:
    http://www.accurateshooter.com/ballistics/tangent-vs-secant-vs-hybrid-ogive-bullets/

    The higher the ogive number (radius in calibers) for a given bullet weight, the less freebore is required to keep the bullet's base above the neck-shoulder junction where the "dreaded donut" can form.

    Custom chambers are spec'ed for a relatively small range of bullet weights/shapes to put enough of the bullet shank in the neck without going into donut territory, while allowing the bullet to touch the lands.

    More here:
    http://forum.accurateshooter.com/threads/freebore.3747855/
     
    Last edited: Sep 27, 2017
    Mikemci likes this.
  4. Mikemci

    Mikemci

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    Dec 3, 2016
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    Thank you for your time and the links Toby. I uderstand what he was saying now.
    I'm a new owner of a 6ppc benchrest rifle and just starting to find the losd it likes.
     

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