Hrmmmf.
Everyone expects to take a tool out of the box and it will do a perfect regardless of the skill of the operator- probably why benchrest shooters tend to gravitate towards volumetric powder drops over time and low volume reloaders buy $300 automatic dispensing balances.
Sorry the LPPM beats every other sub $100 measure, hands down, if you take time to use it correctly and with the right powders.
First, what the lppm does not do well- flake powders and fine ball powders. Don't even bother using it for these- use a Lee disc measure, RCBS, Lyman, Redding measure instead.
What the Lppm excels at- stick and extruded powders such as IMRs, Varget, VV and RL rifle powders. None of the measures in the paragraph above will beat a LPPM for accuracy with these powders.
1. make sure the drum is adequately tight but not overtightened.
2. Before even using it, fill the hopper and run charge it back into the powder bottle by running the handle up and down.
3. Run the handle the same way every time. I run it up, tap the drum 3x with my finger, run it down smartly, tap the drum 3x more. Practice makes perfect.
4. run 3 charges through it before weighing a charge, make the adjustment, then run 3 more through before weighing, repeat until you get it set right.
5. if you make a less than perfect stroke on the handle, dump the charge, run 2 more through before using the charge.
6. if you are running it on a Lee turret press, run the turret all the way around as if you were actually reloading before taking samples for weighting. consistancy is the key.
6. your charges with an IMR powder should be within +/-0.1 gr. But some will say "that's not good enough" I say that's within the accuracy tolerances of most reloading balances, and is actually spectacular accuracy with IMR powders. If you work up loads using a ladder or the OCW method, 0.1 gr difference from the mean is insignificant, and you should be looking other places for accuracy improvement like finding optimum seating depth and reducing runout.