Thread: powder and accuraccy

How are people comparing the accuracy of one load to another ?

Naturally, we arent mostly high skill bench rest shooters so an allowance for occasional or regular shooter error seems a good idea.
There will be a certain amount of random group to group variation in diameter even with good shot delivery, so a small difference just between two x 5 shot groups may not reflect the overall precision. eg if one group is 20mm and the other is 25mm it could be the other way round next time. So perhaps we need a series of 5 shot groups with each load and that will be better than a 10 shot group because that one bad shot will taint the longer string.

One indicator I look for is when the point of impact on the powder weight ladder doesnt change much over 1 or 2gr and then I can combine say 10 or 15 shots into big group as we saw on that yellow target of 3006 K above. At the least, this shows minor errors in powder weight wont affect short range precision.

For longer range, mv sd or es will give some prediction but other variables like bullet concentricity and set will be equally relevant in affecting the amount of moa degradation as the range increases.

I think the F distribution might be a tool to compare variance between two populations but havent had time (nor capacity) to work this through. Would be interested to hear what rules of thumb others are using.