I have to disagree briman. I have tried the same, and I have a proof set of wieghts. With powders like H110, you can get very consistent dips, but for IMR4350, no way. Even unique, I get variances or any flake powder.
I think you are referring to the Lee dippers? I was talking about the Lee Perfect Powder Measure.
Willtill- try this...
-keep you hopper full or nearly full.
-Run about 3 or 4 charges through it before taking one out for weight.
-when you move the handle, give it a tap when its in the down position, and a tap when its in the up position- just be sure to do it the same way every time.
-I wouldn't fret over one or two granules of powder, it really makes zero difference in a rifle load