ACCURACY-GROUP SIZE DIFFERENCE AND n
We want to know if two loads are different, if primer choice or bullet diameters or powder weights make an accuracy difference. This table shows the number of 5-shot groups that must be fired at various % of difference in group size and % sure of the difference.
Instead of just dumping the table here, I’ll make some statements about VALID testing.
Nobody has tested or will test for accuracy differences less than 5%. We don’t know for sure that ANY change makes a <5% difference in group size. We’re never going too know if shooting bullets in the order cast makes an accuracy difference.
Almost nobody has tested or will test for accuracy differences between 5% and 9%. We don’t know, fairly certainly, that ANY change makes a difference between 5% and 9%. We’re probably never going to know if indexing bullets makes an accuracy difference.
As the difference increases to 10% and above, valid testing begins. We can see, fairly clearly, differences of 10% and above. That’s the stuff that we know to be true. We know, with a great deal of certainty, that the Lyman 311/314299 bullet will shoot accurately in most rifles.