Help with NF drop chart **********

Discussion in 'General Discussion' started by bigbuck, Jul 26, 2010.

  1. bigbuck

    bigbuck Well-Known Member

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    I recently shot a nice group at 752 Yards but my NF program had me 6- 1/2 inches low . My program called for 15 MOA Elevation so my question is how do I fudge my software to match up to the correct data for a 752 yard shot ? anotherwords how do I know what the additional 6-1/2 inces of adjustmant is? In terms of MOA ?


    Thanks for your help in advance .

    BigBuck
     
  2. bigngreen

    bigngreen Well-Known Member

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    I would triple check your input data then add/subtract FPS till you match, I'm begining to think the chrony can be a weak link. Berger BC's are GTG and your inputs should be right on so that leaves FPS.

    More ranges and more awesome groups will help get it dialed in for the trajectory.
     
    Last edited: Jul 26, 2010

  3. bigbuck

    bigbuck Well-Known Member

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    My crony is definately a "weak link " now :D . Thanks for your advice i'll check it again and plug in some FPS .

    Bigbuck
     
  4. I start by tweaking the bullet BC until it matches. Then I test again at a couple different ranges to be sure it's consistent.
     
  5. trueblue

    trueblue Well-Known Member

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    All I have ever done is change the FPS and not mess with the BC.
    Might be half ass backwards thou. P ast 1000yards, might be better to fudge the BC.
    The problem w/ the Nightforce ballistics is it does not allow G7 BC, which is alot more accurate for the Berger 210's than the G1 factor.
     
  6. Broz

    Broz Well-Known Member

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    Simple... and I do this with every rifle I set up for someone. I have done many 300 wins with 210 bergers. Your 752 yard data is at the perfect range.

    I would use Bergers G1 BC for the 210 and I assume you are.

    Open your NF program to the front page.

    Click " Program Options"

    then click " tradjectory Validation"

    then enter the distance "752" under target distance.

    then in the 3rd column under "impact pt +/- in. .... enter - 6.5

    then hit apply.

    It now has changed you velocity to match your drop. To check it, it should call for about 1 moa more up than it did for the same shot.

    Done...! next time you will be spot on. I would check it at 1000 too.

    Jeff
     
    Last edited: Jul 26, 2010
  7. Sendero_Man

    Sendero_Man <strong>SPONSOR</strong>

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    same thing I do... great advice and easy to do.
     
  8. bigbuck

    bigbuck Well-Known Member

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    Thanks for all of your replies.

    I'll try Broz instructions as they seem easy enough that even I could do it :)

    Thanks again !

    BigBuck