Well I tried some Unique powder today in my RCBS Uniflow
The grains are much larger than the Acura #5 and make it easier to handle and far less likely to spill.
It also gave better numbers
Within 99% 5.76< X <6.17
3 sigma 99.73% 5.73< X <6.20
Within 99.99% 5.66< X <6.28
The Max-Min divergence is much better, and the Stdev is better too.
I'm also running into resolution and accuracy issues with my scale. I've found I have to wait when the AC is on. A deflection means was selected in GBC.
When I get my own copy of the Lyman book I can check more centered in the safe range (4.8 to 6.2 grains). Here I was just running with 6.0 as my point of aim.
But I think with this powder I could have better results.
I'll need to test at the range of course.
One warning I did get was that Unique burns very dirty.