[Unclenick]

James,

No problem. But Jim's suggestion would be a good step, too. I think I'd run the next round robin series first, though, to better investigate the tight group for being a fluke or not and what happens just below it. If we can validate that flat spot centered around 40.95 grains (or get its center better defined or find another below), then we should start looking at tuning seating depth for sure.

Toward that end, do you have a tool for measuring bullet runout?


Eppie,

Yes, an engineer. Though I confess six-sigma black belts and other statistical tools were not as popular when I was in school. I got through basic stats class, then took a quantum mechanics class where we were calculating particle position probabilities by triple integral form Eigenfunctions. A little like graduating from the wading pool straight to Olympic platform diving. I've had to scramble to fill in the middle ever since.

All the variables you mention are there, so we are attempting to hold all but powder charge influence constant. It's never completely successful, but with the statistics to help see through the noise as best they can, we should get a good sense of what the powder charge adjustments are contributing.