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How to measure my groups?

Discussion in 'Handloading and Reloading' started by dc.fireman, Sep 29, 2011.

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  1. dc.fireman

    dc.fireman Member

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    I have a simple question, when it comes to measuring my group sizes:

    When examining a particular group for accuracy, which measurement should I be looking at (I'm using On-Target, to determine my measurements)?

    Is it the Max. spread? Or the average CTC (Center to Center)?

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  2. BigN

    BigN Member

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    Many people measure their groups in many ways. I take a shot group, measure center to center of the furthest two apart, and that's the outer size of the shot group. Some average, some draw a square and measure that way. If you have three shots, two are 1/2" apart but one is 3/4 inch from the furthest one, 3/4" is your shot group size.
     
  3. dc.fireman

    dc.fireman Member

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    Thanks!
     
  4. esheato

    esheato Member

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    I measure outside to outside, then subtract the bullet diameter giving me CTC size.

    You could always use OnTarget software too.
     
  5. Walkalong

    Walkalong Moderator

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    Either way gives you the same thing, and is the correct way to measure group size.
     
  6. Fatelvis

    Fatelvis Member

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    I measure outside to outside of my bullet holes and subtract 3X the bullet diameter. I seem to get better groups that way.... ;)
     
  7. dc.fireman

    dc.fireman Member

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    Thanks, thats what I'm using.
     
  8. jcwit

    jcwit Member

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    I make a 3 shot group, measure the center to center of the 2 closest and thats my group size. Man alive do I ever get some fantastic groups using this method.

    Also when fishing I have a special tape measure to measure even the smallest fish.
     
  9. gamestalker

    gamestalker member

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    I use a yard stick to measure my groups. It faster than having to mark a ruler end to end, and more accurate. There is a big difference between 35.43" groups and 34.98" groups.
     
  10. ConcernedCitizen

    ConcernedCitizen Member

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    I don't measure my groups, I just count the number of shots that actually hit the target...

    Some days I shoot 3 shot groups, other days I shoot 5 shot groups...;)
     
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