1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

How to measure my groups?

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

  1. dc.fireman

    dc.fireman Well-Known Member

    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)?


  2. BigN

    BigN Well-Known Member

    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 Well-Known Member

  4. esheato

    esheato Well-Known Member

    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

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

    Fatelvis Well-Known Member

    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 Well-Known Member

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

    jcwit Well-Known Member

    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

    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 Well-Known Member

    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...;)

Share This Page