I'm also interested to hear which powder measures give you the best results with coarse flake powders.
John,
I started reloading using an RCBS Little Dandy powder measure. It works great but the fixed cavity rotors get expensive and they are not very flexible. I frequently found I wanted a powder charge that fell between two rotor sizes. I bought my rotors when they were $1.98, I believe they are in the $5-$6 range these days.
For pistol charges, I use a Redding 10-X. I have excellent results with it and the micrometer adjuster makes it easy to return to a setting, or make adjustments when dialing in a particular powder charge. I like the 10-X so well that I modified one for use on both my Hornady L-N-L and RCBS Pro2000 progressive presses.
I like a micrometer adjuster on my powder measures. It does not make the measure throw any more consistently, but it does make adjustments easier and quicker. Also, I like to have a baffle in the reservoir of my powder measures. I make sure the holes in the baffle do not directly line up with the cavity in the metering drum. Many folks have good success without a baffle.
I also have an RCBS Uniflow, Midway Indispensable, Hornady L-N-L, and Harrell Custom 90 Powder measures. I use them all but each has its specific charge sizes that I have found each measures works well at. Also, with multiple measures, I do not have to change over a measure to the other drum size. It helps that I have been collecting reloading equipment for over 30 years.
A side note, since I modified a Redding 10-X to operate on the progressives, I use the Hornady L-N-L less and less.
At one time I had a Lee Perfect powder Measure and I could not get it to work for me.
Within the capacity limits of any of my powder measures, all of them perform well. I have just found some small benefit or feature that makes a particular powder measure work a bit better for my purposes. There are many other excellent powder measures out there, I just have not tried them--yet.
Hope this helps.