I use a Hornady beam scale as well. It has been very consistent over many years throwing the same weights time after time.I use another digital scale to check and I use a known weight to calibrate the digital one. The beam scale is always .2-.4 gr higher.
For my use, I would not worry if it was off by .2-.4gr as long as it was the same every time. As long as I use the same scale all the time, I would not have a problem. If it started throwing random weights, I would see an accuracy problem. To prove this, I don't use known weights to check it, but I do use small items that I weighed years ago and recorded those weights and kept them on my bench to use to check consistency. These items are about the same weight as what I might use for various powder charges. Sounds bush league, but it absolutely works and insures consistency which is paramount for accuracy.