Finally took chrono to the range and now what?

Discussion in 'Reloading' started by 243yote, Mar 16, 2011.

  1. 243yote

    243yote Well-Known Member

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    Apr 2, 2009
    So i finally took chrono to the range to see what my loads would do. Finally just used old spotting scope tripod to mount chrono on. It works great! Now my question to you more experienced loaders. How do i interpret the chrono info? SD,ES,Avg? My best groups had the lowest numbers. I worked up a new load with new powder. Tried some old loads just to see what i was getting also. Old loads were just a bit faster. gun)
     
  2. mountainman

    mountainman Active Member

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    Jan 14, 2011
    SD, standard deviation, is a statistical measure of uniformity of your shot string. ( to much math to mess with)
    ES, Extreme spread of your shot string, high and low velocity spread.
    example;
    shot#1 3000 fps
    shot#2 3015 fps
    shot#3 3030 fps
    ES = 30 fps
    AVG, average velocity of your shots in your shot string.
    example; AVG, 3015 fps

    Look to workup a load that keeps your ES as low as possible and that should be your most accurate load as long as you do your part shooting. I try to get my ES in the low teens and thats good enough for me. slower loads are the most accurate alot of the time but I look for powders that give as close to 100% case density as I can get and play with it from there.
     

  3. 243yote

    243yote Well-Known Member

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    Apr 2, 2009
    Thanks for answering.