The "Perfect Powder measurer" is not really that perfect; it's close though. I weighed each charge on the Lee Safety Powder scale and found that I had to add or remove several grains 2 out of three times, to get to the desired weight. The measuring scale on the Perfect Powder Measurer is not accurate either, hence the need to weigh each powder charge with the scale. Hope the scale is accurate itself....
You probably have it backwards- your scale is not as accurate as your powder measure. Is no way that a cheap piece of tin mounted on an axle with tin counterweights is going to be as accurate as a drum that is constantly filled to the same volume of powder, unless you are doing something wrong with your measure. I've checked the LPPM against my Ohaus scale and its dead on the nuts on, charge after charge with IMR 4064 and IMR4895. You still need a scale to set the Lee measure regardless of its graduations.