I really wonder if there is a "better" powder measure.
I have three, the Lyman 55 Powder measure, a Redding, and a 70's-80's vintage Bonanza. I also use the Dillion 550B measure.
The bonanza is taller and holds at least twice the powder of the others.
I have noticed that the average charge weight varies based on powder column height in the Bonanza. So maybe powder follows the fluid dynamic equation of Pressure equals Rho g H. Increase the height of the column and you increase the pressure at the bottom.
All these measures work on gravity. Stay in the same latitude and altitude, gravity does not change much day to day. It is gravity that fills the powder cavity. Maybe that is why the powder tubes in most powder measures are short, to give the illusion that the measure throws consistently.
Anyway, except for powder height changes, all of these measures throw about the same. Charges vary more based on technique than which measure is throwing them. My charges vary a lot if the measure gets bumped shearing powder sticks.
I have buds that have bought the most expensive powder measures out there, one of which is the Harrell. One guy told me that the expensive measure throws the same as the less expensive ones.
I suspect powder measures are like expensive watches. Guys have told me their mechanical Rolex is more accurate than their $25.00 Quartz watch. Which is absolutely implausible.
http://www.chronocentric.com/watches/accuracy.shtml#quartzvsmech People associate price with precision.
I dump all my 308/30-06 short range charges (300 yards or less) with IMR 4895 and IMR 4064 on the Dillion. I stopped checking the thrown weights because the variations are at least half a grain, and it did not make any difference on paper.
Something as long as IMR 4350, the thrown variences are more than a grain and a half, and I don't have any powder measure that throws that well.