What is your best number?

[Rocket35]

Just curious, because I had the best results I have ever seen in 4 different loads today. They were with the same components but different powder charges I was testing out today. They went 8-7-7-6 in succession. I was wondering if these standard deviation numbers are above average or par for the course results?

[FLL1911]

They are pretty good. It does mean that your reloads are very consistent. Small changes in powder charge although changes the final velocity should not change the accuracy of the load if all other components are the same. I get low std dev on my loads whenever I can keep the powder flow consistent from one case to another, and the powder weigh is not very close to the minimum recommended (possible blow-by) – usually between 7 to 15, but as low as 3 – 4 in some loads in 40 cal and 45 ACP (I use mixed headstamps).

[HSMITH]

3n-37 in my Open gun will often turn in ES of 7 or 8. I don't really worry about it though. I subtract the SD from the average and as long as that number still makes 172 power factor I am good to go.

[Rocket35]

I am not obsessing, just curious. Thanks for the input guys.

[HoMiE]

3n-37 in my Open gun will often turn in ES of 7 or 8. I don't really worry about it though. I subtract the SD from the average and as long as that number still makes 172 power factor I am good to go.

I usually get SD around 8~10 using same headstamp brass, around ~15 when using mixed headstamp in 9x19.

With normal distribution, 1 SD will cover 68%, 2 SD will cover 95% and 3 SD will cover 99%.

[Rocket35]

My results were from using "range floor" mixed brass (nickel mixed in there as well). Seems like a lot of work to separate for SSTK loads.

[ben b.]

I agree, it is a lot of work separating. Too much for me in pistol rounds. My SDs range 7 -14 for at least 10 shots in mixed cases, in 9, 40 & 45, looking over my results I have a lot of SD = 11, lowest was 6. Anything under 20 is probably good enough for action pistol work.