• Last Post 28 March 2019
joeb33050 posted this 28 March 2019




This is about shooting groups. The analysis is based on CBA NM records, 2000-2013.


Perfect shots go through the same hole, inaccuracy is caused by some elements. There are four classes of causes of inaccuracy, the inaccuracy elements.


EQUIPMENT, bullets etc.  EQUIPMENT causes ~24% of inaccuracy


WIND, everything affecting the bullet from muzzle to target. WIND causes ~ 6% of inaccuracy.


SKILL, the ability of the shooter to shoot small groups. SKILL causes ~20% of inaccuracy between the first and second place shooters, with the % decreasing as “place” increases.


CHANCE/LUCK, the product of variation. CHANCE/LUCK affects inaccuracy in complex ways. Here is an example of 5 and 10 shot GROUP matches, with the shooters numbered 1 through 5. The shooters have shot a zillion matches, and are ranked by “place”, #1 through #5. Here are SOME of the outcomes:


#1 will shoot < #2 group size, 89% of the time.


#1 will shoot > #2 group size, 11% of the time.


#1 will shoot > #3, group size, 9% of the time.


#1 will shoot > #4, group size, 7% of the time.


#1 will shoot > #5 group size, 6% of the time.


EXCEL workbooks are available on request.


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Ken Campbell Iowa posted this 28 March 2019

... hi joeb ... this is a hoot !! ....  thanks !   

barrel heats up, vibrates out of sweet spot ;  high humidity, stock warps ....

shooter is constipated, can't concentrate.  feet hurt. low blood sugar. ... 

maybe the shooter is just more " equipment " ..

ken, < average 64 per cent of the time

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