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Re: Range Report - 7x300 Weatherby - 5-28-15
Old 06-01-2015, 02:00 PM
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gitano gitano is offline
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Default Re: Range Report - 7x300 Weatherby - 5-28-15

Here's my statistical analysis:

Of primary interest to me is the value for the Area of the 95% Confidence Ellipse seen in cell "F16". For this three-shot group, that value is half a square inche. What that values predicts is the area into which I could expect the next 95 out of 100 shots to go at 100 yd.

If you look at cell "B3" you will see the value of "Student's t". That value is based on the sample size. The larger the sample size, the smaller the Student's t value. The Student's t value is a MULTIPLIER of the variance observed in the shot string. Therefore, the greater the number of shots you are using to determine the parameters (average, variance, etc.) the better the estimate of 'reality' you will have. Since the smaller the sample size the less confidence one has that the samples used actually REPRESENT REALITY, you have to broaden the PREDICTED parameter.

Taking "max spread" as an indicator of THE BOUNDARIES AROUND where the "next bullet" is going to hit is "optimistic" at best. Put another way, it's fooling yourself. There are PLENTY of people in the world that want to fool me, I don't need to fool myself. What I want to know is my BEST GUESS at where the 'next' bullet is going to hit based on where the last "X number" of them hit. Max spread is "easy", but it's not "good" for making that prediction/guess.


PS - If you have MicroSoft Excel and would like a copy of the spreadsheet so you could perform your own calculations, shoot me a PM and I'll email a copy with some instructions to you .

Then you will know the truth, and the truth will set you free. John 8:32

"We make men without chests and expect of them virtue and enterprise. We laugh at honor and are shocked to find traitors in our midst. We castrate and bid the geldings be fruitful." ~ C.S. Lewis.

Do not confuse technical skill for wisdom and do not confuse strength for skill. Paul Skvorc

Last edited by gitano; 06-01-2015 at 11:11 PM..
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7mm, 7x300 weatherby, confidence ellipse, range report, statistics

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