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... Re: The never-ending 3-Shot groups vs. 5-Shot groups argument. In Brian Litz' book Applied Ballistics, 3rd Edition ... Brian Litz included a formula/chart to calculate 5-shot groups using 3-shot groups (and a host of other combinations). I posted a target that I proof-grouped a 16" 5.56 MGU (Match Grade Upper) today. The 3-shot group measures 0.570", and the 5-shot group measures 0.650". Multiplying 0.570 x 1.28 = 0.730". The 5-shot proof-group beat the Litz formula in an example of one (1). The struggle is real 🎯 ML


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mark_133_navy Less is more - More is less...one holer's 🕳 need respect ✊ ... Three quarters of this theory is the "nut" 🥜behind the trigger 2 likes

grantlucke Sure, but what is "likely" as Litz's verbage states should not really be extrapolated to the real world UNLESS there are a good sample size of 3-shot groups. For example, the scale factor from 3-shot to 5-shot is 1.28, the caveat is that the scale factor is based on a normal distribution within sufficient sample size to prove that distribution is true. In short, shooting 5 3-shot groups and averaging those group sizes THEN extrapolating with the 1.28 scale factor to 5-shot groups would more likely match the actual performance of the barrel/ammo. Simply put, there is no getting away from sample size as the most reliable measure of performance. Determining what group size is likely (based on probability) can only be improved by sample size. 5 likes

  -  laruetactical @grantlucke ... Great to know you can read. 2 likes

thebigred692000 Thanks for this. I have wanted to learn more about ballistics. Guess I found my first book. 1 like

lineman7750 Brian litz is a genius! And you are a Genie. A supernatural being that bends the laws of the universe to his will. 1 like

reeseracing23 Good info

frigglebiscuit Fine, shoot 10 then😂 1 like

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black_wolf_supply @johnfenzel