Robinhood, I use an RCBS Chargemaster which I've verified against a beam scale to be plus/minus 0.1gr.
Likewise, However randomly I get a gross over charge that is not shown on the scale and random short charges. I would say 6 or 7 out of ten are right on the money. I have tried a lot of the mods accept for the insert sold on Accurate shooter.

My Pampered Scott Parker tuned scale is the last word.