603country, three shot groups have a 15% to 20% chance of representing what a 50-shot group will.
Shoot more shots per test group; at least 10, else your data's not statistically significant and far from being what's good to make decisions on.
If you still think 3-shot groups are good enough, prove it by shooting 5 of them with the same load. Then let me know which one you pick to represent the accuracy of that load.
Basics of testing ammo: if all the groups shot with a given load are different sizes, you're not shooting enough shots per group to get meaningful info on that load.
US Navy Distinguished Marksman Badge 153
Former USA Palma Team Member
NRA High Power Long Range High Master
NRA Smallbore Prone Master
Last edited by Bart B.; February 19, 2013 at 02:37 PM.