minimum seat depth

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by stvnbrg, Apr 26, 2014.

  1. stvnbrg

    stvnbrg Active Member

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    so I have heard the rule of thumb that i have been using that the bullet should be seated at least one bullet diameter into the neck, How crucial is this? Trying to load VLDs for my 25-06 in order to stretch out to the lands i only achieve about 0.180 into the neck so quite a bit short of 0.257. Good to go? recommendations?
     
  2. jfseaman

    jfseaman Well-Known Member

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    Is that .180 total or .180 bearing surface?
     
  3. stvnbrg

    stvnbrg Active Member

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    That's bearing surface
     
  4. jfseaman

    jfseaman Well-Known Member

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    That is %70 of diameter of bearing surface in the neck.

    It's more than I have form some loads.

    I'd love to hear more from others but for me it would be good to go.
     
  5. stvnbrg

    stvnbrg Active Member

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    What about run out issues?
     
  6. jfseaman

    jfseaman Well-Known Member

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    I'm not having any run out problems.

    I treat my ammo carefully so it doesn't get bent.

    If you are going to run then in the mag, check to make sure that if feeds very well. If it were me, I'd make up some dummy rounds, check the run out, run them through the action and check run out.

    Assume Berger 115 VLD, shank seating depth of .180, total seating depth of .320, COAL of 3.369.

    But hey assume makes an a** of u and me.:) So I could be all wet.
     
  7. gohring3006

    gohring3006 Well-Known Member

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    I'm with Fred as long as runout is minimal 70% I could live with it unless it was a 300 win mag then 70% of the neck would concern me
     
  8. stvnbrg

    stvnbrg Active Member

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    What would be the consequences? Low pressure?
     
  9. LouBoyd

    LouBoyd Well-Known Member

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    Rules of thumb often to make other more important conditions happen. If the bullet engages and seals in the lands while the bullet shank still is still supported by the neck it should be OK. If the bullet is unsupported at both ends even briefly there will be blowby and likely poor accuracy. I'd be ok with .0180" shank seating depth if the jump to the lands is 0.0 to 0.04".
    I'd prefer that to having .257 seating depth and 0.11 jump to the lands. better would be to use bullets with a bit longer shank.
     
  10. gohring3006

    gohring3006 Well-Known Member

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    mainly runout theoretically you could get good pressure because of more capacity but the risk o misalignment from dropping, feeding from mag etc. As for the 300win. The neck is smaller than caliber so I would like 100% contact just my opinion...