I have never seen any volumetric powder measure throw any powder, even Unique, with a variation in excess of +/- 0.4gn. You appear to be getting +/- 2.0gn. There is something seriously wrong with your measure.
Did you throughly degrease the measure, including the drop tube? You didn't degrease and lubricate it, did you? The only lubricant should be powdered graphite.
If you throw a charge, can you tap on the drop tube and have any more powder drop out?