Bumping against the stops when dumping and filling the metering chamber usually causes inconsistent loads with the Perfect Powder Measure. Be gentle at both ends of the stop when charging powder.
Also failure to condition the measure by running a pound of powder through the unit will cause inconsistent charges. You can speed the conditioning by dusting the metering surfaces with powdered graphite. Powdered graphite is available at most hardware stores (often used as a dry lubricant for locks). Empty the powder from the hopper of your perfect powder measure. Remove the screw from the crank plate and remove the rotor from the body. Apply some powdered graphite to the inside of the body and work it in with the rotor. Repeat this until you get an even coating of graphite on both the rotor and the body. Re-assemble the the powder measure. The powdered graphite will make the mating parts slide past each other a lot easier.
Lastly some powders do not meter well, Unique powder is one example that meters with "casual uniformity."
