Like RR said, disassemble your scale and with Alcohol and q-tips clean your pivot knives well. DO NOT ADD OIL OF ANY KIND ANYWHERE on your scale as this will cause serious inconsistencies. Also double check your hanger and make sure it is freely swinging. If it isn't this will effect your COM because the weight being measured will not be centered to the beam axis. It doesn't take much dust or anything at all really to affect a quality beam scale. Your better made ones are very intolerant to dust. They are precise instruments and have to be cleaned quite often and in the proper way. Without that you will start getting bad reads and that is a BIG no no in reloading.