Thread: Obtaining more information from your groups - overlaying groups

Most of what is perceived as "shooter" effects or groups opening up from "barrel heat" is demonstrably just groups filling out with more data. I have fired dozens of groups of various sizes from various rifles over the past year and when you get larger samples the perceived effects just go away - you just get a real picture.


Groups will (almost) ALWAYS get larger with more shots. You are just building a more true picture of the actual distribution of shots that the rifle system will produce.


Here's my 2x 10rd groups from yesterday with the factory 73gr ELD overlaid using this tool - they just fill out into a nice rounder picture of what the dispersion of the system actually is.



Mean radius 0.068MRAD - I should expect that 95% of shots I'd fire from this system would fall inside a circle of diameter 0.28 MRAD or thereabouts. So I can expect to reliably hit 0.3MRAD targets IF I can get perfect zero, perfect adjustments for range/wind, don't have excessive vertical spread at the relevant range due to velocity variation, etc - and I don't make any egregious shooter errors in the field.

Group extreme spread, of enough shots, give you a rough relative index of whether a rifle system is more or less precise than another. Mean radius gives you that, and a predictive tool for what size targets you can expect to hit.