Re: RCBS Chargemaster accuracy test
It's hard to tell from this if either scale was best used..
Efforts aside, you can't just set-n-forget a dynamic load with accuracy. Which is why relaoding scales are better -for reloading,, than lab scales.
I'm confident that with a little tinkering/tuning, you'll get a lot better with your CM.
For one, you'll find that you need to disturb the pan, allowing better readings to re-settle.
You might also notice that the CM can be and should be tuned to each powder specifically.
There is timing, and a sense for each charge quality as observed.
The route you've chosen(validation with higher resolution) will really pay off by helping you operate the CM better.
It's exactly what I did, with the same scale(well, acculab), and I got good enough with the CM (tinkered & tuned) to discontinue validation. I now know my charges are right, or wrong, with better accuracy than the CM scale is rated.
This is similar to issues people create with QuickLoad reloading software. Some expect professional results, with novice use, and that don't EVER happen by chance.
You must make it happen.