I purchased the magazine in question just for this article, and found it useful, thanks for writing it. I have been running tests with my powder measures, and asking friends with different models to do the same.
Would you mind answering a couple questions about your data? I'm using your numbers as a point of comparison but could not find in the article some of the details. Specifically regarding the powder variation numbers shown in the second table, I gather that those numbers display total variation, not +/-, correct? Is this an average, a standard deviation, or the extreme spread? Also, how many data points did you collect to determine them?
And of lesser concern, but I am still curious, did you discount throws where the extruded powder kernals were cut hard by the measure? I used to toss those ones out when loading, but in my measurements so far, they seem to fall in with everything else.
Empirical results rule!