RCBS Electronic Scale zero point wanders?
I have an RCBS Rangemaster 750 scale that I have had for a couple years. Lately, after I calibrate it and zero it with the pan on, the zero point wanders up and/or down. I typically check every eight thrown charge and when I go to weigh a charge maybe a minute later, the zero has changed. Sometimes by 0.1gr but sometimes has gone to -0.4 or greater. I rechecked the level of my bench top and it is fine, I even insure there is no airflow around the scale from fans, wind, etc.. Starting to worry me a bit, I have to put the empty pan back on, re-zero the scale, then press on. I occaisionally shut it off, recalibrate with the weights, but it will still wander like that? Do you all think it is defective or is this typical? It did not seem to do this when it was new. I am getting concerned about the possiblity of loading too hot without realizing it. Thanks in advance for your input.