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Thread: How do you measure your group size?

  1. #1
    Boolit Master freebullet's Avatar
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    How do you measure your group size?

    I know there are different programs, methods for all kinds of competition, or even with a ruler. I'd like to know how folks here do it. Is there a consensus or standard? Any useful info is appreciated.
    If you think your a hammer everything looks like a nail.

  2. #2
    Boolit Master


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    I use a dial caliper.
    Select the two widest holes and measure from the outside of one hole to the inside of the other.

    That will be the same distance as center to center.
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  3. #3
    Boolit Master
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    ^^^^^^^^^^^^^^ Same here!

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  4. #4
    Boolit Buddy


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    Same also

  5. #5
    Boolit Master Hannibal's Avatar
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    Quote Originally Posted by williamwaco View Post
    I use a dial caliper.
    Select the two widest holes and measure from the outside of one hole to the inside of the other.

    That will be the same distance as center to center.
    + 3^^^^^
    Last edited by Hannibal; 10-28-2014 at 09:11 PM. Reason: too slow typing

  6. #6
    In Remembrance
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    Tape measure, 99% of the time a 16 footer will do, but I keep a 25 footer just in case. lol

  7. #7
    Boolit Master



    NavyVet1959's Avatar
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    Quote Originally Posted by starmac View Post
    Tape measure, 99% of the time a 16 footer will do, but I keep a 25 footer just in case. lol
    Obviously we have the same prescription for glasses.

  8. #8
    Boolit Master

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    Quote Originally Posted by williamwaco View Post
    I use a dial caliper.
    Select the two widest holes and measure from the outside of one hole to the inside of the other.

    That will be the same distance as center to center.
    Way easier than I've been doing. Outside to outside minus the bullet diameter. I'm an idiot.

  9. #9
    In Remembrance
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    Quote Originally Posted by NavyVet1959 View Post
    Obviously we have the same prescription for glasses.
    Yup, I need to get some new ones, it is getting hard to see the little marky markies on the tape. lol

  10. #10
    Boolit Grand Master

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    Quote Originally Posted by williamwaco View Post
    I use a dial caliper.
    Select the two widest holes and measure from the outside of one hole to the inside of the other.

    That will be the same distance as center to center.
    If I'm having a really good day I have to measure total group diameter and subtract boolit diameter.
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  11. #11
    Boolit Grand Master

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    At the range I use the 6" metar scale in my pocket if it merits it it goes home to measured with calipers. I measure inside to outside also. Sinclars has an attachment for calipers with differnt calibers eched in it.

  12. #12
    Boolit Master
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    I measure outside to outside with a micrometer and subtract the bullet diameter because all of my groups have the holes touching.

    I actually don't measure many groups except for with a few rifles using the above caliper method since the rest just need to be minute of critter.

  13. #13
    Boolit Master Dan Cash's Avatar
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    Quote Originally Posted by Nise View Post
    Found out I've been doing it wrong for a long time, I always measured Outside to outside, 1/2" group could be covered by a 1/2" dot. Grew up calling it by coins, cover it with a: dime, nickel, quarter, half dollar etc. Guess that just means the 1/2" groups were even better. What can I say? I'm modest, lol
    That is the way I do it. Half a bullet on a target won't kill it as a rule.

  14. #14
    Boolit Master
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    Depends on what I'm shooting and who I am with.

    But generally if I can cover it with my hand for rifles @ 100 yds its "Good", less than 3 fingers is "Great", all touching is "F***ing AWESOME"

    Handguns if I hit what I am aiming at outside 7 yds "Its all good"

    This all changes of course when you or Paul are present. Then we have to get all technical and S*@#.
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  15. #15
    Boolit Grand Master
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    I use a tape measure or a caliper, depends on how close I want to be.
    You will learn far more at the casting, loading, and shooting bench than you ever will at a computer bench.

  16. #16
    Boolit Grand Master
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    Oh, there is a different method. Sometimes I use a trash can to measure group size. That is the method I use when the tape measure isn't even needed.
    You will learn far more at the casting, loading, and shooting bench than you ever will at a computer bench.

  17. #17
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    Did I hit the target? Good, am I mostly in the center, great, holes touch super, 3 or more rounds in one hole awesome. I don't measure, normally if it is good enough to kill whatever I am shooting it that works for me.

  18. #18
    Boolit Master gpidaho's Avatar
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    I have a 100' cloth tape in one foot increments as used in the logging industry. Works for me GP

  19. #19
    Boolit Master
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    The correct measurement of group size is center to center of two farthest apart, as has been posted. Using that method is logical also in that smaller calibers won't have advantage over larger calibers.

    "Of course all my rifles are one hole tack drivers". Followed by the obligatory, "IF I DO MY PART"

  20. #20
    Boolit Master

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    I use the Precision Firearm Records Digital Target Scoring Feature

    Just bring the target to the laptop or desktop, place the target on the screen and move the scoring cursor under the bullet hole and click.

    The moniter calibration system can be adjusted to quite accurately measure, record and retrieve the group size for any and all targets fired from an individual firearm.


    Place the target on the screen and click under the bullet holes




    The computer determines the hole center coordinates of each shot then calculates and displays all the relevant group size data.
    Last edited by Tom Myers; 10-29-2014 at 07:25 AM.
    Respectfully,
    Tom Myers
    Precision Shooting Software


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