Thread: .243 load development part deux

Originally Posted by Stocky

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So in the above image portraying a 30 shot group. If you at random picked any 3 shots it could give wildly different results. Maybe you shoot the 3 worst in that group maybe you shoot the 3 touching but most likely you shoot something in the middle.but there's a huge range of possible outcomes.

Below an average expected increase in groups size vs shots fired. You will see that even 50 shots groups expect to increase 7% from the average 30 and vary 10% between 50 shots groups. This is because the group size only factors in 2 shots. Mean radius becomes consistent much faster and id pretty steady around 30 shots.

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The important thing with the right-hand side of this table is that the correction factor, e.g. from 3-shot to 5-shot groups is for an AVERAGE group, and you need to shoot 10+ 3-shot groups to obtain a reasonable average