Thread: Testing a conventional approach to load development

Originally Posted by Makros

@gimp I don't doubt your results but out of interest.

Questions;
How were you able to determine the location of each shot to obtain each shot location and radius? Looks difficult to do for the targex group unless this is was a group derived from multiple overlapping targets.
To assess significance are you visually comparing mean radius and 95% CI error bars or running a statistical test?

Are you able to provide standard deviations or raw data? I'd be interested in having a play and work out statistical power and effect size to give us an estimate of what your sample size would have to be to confidently detect a group that is over 50% bigger than another? I suspect very few shots when the difference is >50%. I do warn though that detecting the difference between two groups is different from understanding the precision of a single load.

The targex group I have the 4x 5rd component groups available on separate targets (that were precisely overlaid over the 1 that contains the composite group) allowing me to precisely measure X & Y for each shot. I have then corrected X/Y by the MPOI offset from point of aim to obtain radii from MPOI.

The standard deviation for the mean radius of the targex load is 0.38cm and the SD for the hornady load mean radius is .58

a T test (paired, 2 tailed) in excel gives me .002 for the Targex vs Hornady and .53 for the 2 .260 loads - it's clearer visually to show the CIs overlapping for the audience

Happy to share raw data - I'm not an expert statistician by any means and peer-review of my work is always welcome