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 US Navy & Palma Rifle Team Member
NRA High Power Master & Long Range High Master
NRA Smallbore Prone Master
Last edited by Bart B.; February 19, 2013 at 02:37 PM.