Standard Deviation

[gregrn43]

When y'all are working up loads for a hunt, what is the standard deviation that you look for? I'm working up a load for my 300 win. 180gr scirocco with H1000. With 80grs I have a std dev 10.4. Max velocity is 3102, min velocity 3072. Rifle is a Ruger M77 mark II 24 inch barrel. This SD was with a 5 shot group. The load shot pretty good, but I think I need to tweak my sitting depth a little. I cant extend it very much because it will not fit in my magazine. I shot 4 different loads and this is the best SD that I had.

 

[USMA84DAB]

10 shot group - Std Dev of 7.5 FPS - looking for 2650 FPS, 10 shot average was 2654 FPS. I called it good.

 

[samson7x]

I like it to be <10 but if it groups 0.5" at an SD of 14, I'm rolling with it.