Applying Britishmuzzleloader's "Figure of Merit" to Pistols

[RJ]

I have been a big fan of Rob at Britishmuzzleloader's videos on Victorian era rifle shooting. His videos are entertaining and informative.

One I only discovered recently, had me very intrigued however; it described a numeric technique for evaluating long-range groups for size called "Figure of Merit":



Rob set up a spreadsheet to compute FoM for his rifle work ups, and I was interested in how it could apply to pistols. So I located the downlink, provided by Rob, here:



(Right click the blue at the bottom, "save link as", to download the *.xls file onto your computer).

After downloading the spreadsheet, I made the adjustments for my pistol (1911), and used it to calculate FoM for a typical drill I shoot, The Test. I opted to use @stomridertx's excellent B-8 targets,which feature a convenient 1" grid. This makes entering the data for X and Y a bit less of a chore, since you can eyeball the data in a few minute to plug it into the sheet.

Here is a recent example I used to calculate FoM using the calculator:



What I find useful is that FoM is a metric based solely on the pattern of the group, not necessarily a raw "score". It removes the sighting (although it provides feedback on that, as well) element from the score, giving you a good idea of how well your gun is grouping. I am a math nerd and find this stuff fascinating, so I thought this was interesting enough to post.

[JCN]

What I find useful is that FoM is a metric based solely on the pattern of the group, not necessarily a raw "score". It removes the sighting (although it provides feedback on that, as well) element from the score, giving you a good idea of how well your gun is grouping. I am a math nerd and find this stuff fascinating, so I thought this was interesting enough to post.

Thanks for posting! I think that is nice that it addresses one of the criticisms of group shooting (the sighting system and whether that's a different hold for the target at hand).

If you haven't checked it out, there's an app called Ballistic-X that is kind of cool. It allows you to circle impacts on a target and it calculates group size and deviation.