Mine has worked great... i just make sure to do the same warmup & calibration procedure each time. I turn it on the night before if possible so it sits on a while. While i'm getting ready to load i set one of the 50g weights on it for 10 mins or so, then pull it off, let it rezero if needed, and put it back on. I wrote the number down that it likes each time BEFORE calibration. After that, make sure you calibrate each time, i verify and also write down my powder pan weight to make sure the scale is reading that to be the same each time. I've had no issues doing this.
When emptying, I get as much powder out as possible with the drain tube on the side, whatever is remaining i blow out of the charging tube with a little can of computer duster to make sure all the grains are out.