RCBS Chargemaster Combo vs Lyman 1200 DPS 3

[HeavyTread]

grain of powder stuck someplace putting it right in between the two values?

Maybe. Next thing I'll try is to invert it and see if I can move it around gently to see if something comes out. The design of how the platen inserts into the body of the scale makes it possible that a kernel of powder could fall into it.