Carl,
I spent my career as a research chemist using expensive electronic lab scales reading to .1 mg and .01 mg, & I have Ohaus 10-10, and 5-0-5 scales, an RCBS chargemaster, and a Grizzly Industrial that reads to .01 grain at home. Lab balances that read to .01 mg need to be on vibration isolated tables which you won't find in at home.
All electronic balances are going to drift and need to be zeroed or tared before making a measurement. Gravity doesn't drift, so beam balances don't have this problem. Drafts will affect both kinds of scales. A properly tuned Ohaus 10-10 balance will weigh very precisely, & detect 1 granule of powder.
With the chargemaster, you can punch in the charge you want. The CM zeroes itself, and the dribbles up to that weight. It will zero itself before dribbling every charge, so drifting of the readings is not a problem. My experience is that the CM is more consistent than any of my powder measures (Harrell, Homer Culver, 2 Reddings, Lyman 55, and Belding & Mull). The vast majority of matches are won using measured charges.
The bottom line is that the cheap electronic scales for $30-40 won't last. Your Redding scale is fine to set a power measure, but for repetitive measurements a good electronic scales might be more convenient. If you want automated weighing of powder charges, the chargemaster is good. Your money, your choice.
Regards,
Ron
