In recent times I have been using my old RCBS 5-10 balance arm scale for reloading. It must be thirty years old, at least. It was manufactured for RCBS by the Ohaus Scale Corporation. It weighs up to 500 grains with an indicated accuracy of 0.1 grains. With care, and interpolating between the 0.1 grain calibration lines, you could probably get accuracy of down to 0.02 grains if you persevered.
I also have a Lyman DPS 1200 electronic scale which dispenses a measured charge to an accuracy of 0.1 grains. I have not been using it lately because I have only been loading small quantities of ammo, using three separate powders and it is much quicker to use the balance scales when you factor in the half hour warm-up time and the cleaning necessary between different powder types.
The old RCBS scale is at least as accurate as the Lyman too, I must say. I have had a lot of practice over the years and find I can manually dispense powder charges faster than the Lyman scale.
Today, faced with a big run of a single charge type I got out my old RCBS powder dispenser and decided to use it. I also set up the Lyman scales and decided to weigh the charges thrown by the RCBS powder thrower. If they were good enough, then I would continue to use the thrower.
It must be twenty years since I last used the RCBS thrower and it took a little while to adjust it to the 25.0 grain charge of W748 that I wanted. I put a little graphite dust on the rotating dispenser to get it working smoothly once more. I threw and weighed 10 charges after settling in on what appeared to be a steady 25.0 grain charge.
The first few charges varied by about 0.2 grains, but then quickly settled into a very consistent 0.1 grain variation. I was quite pleased with that and, even though it slowed down the reloading process, I decided to continue on and weigh each of the first 100 reloads in order to more thoroughly check the powder thrower consistency.
It is important to maintain a consistent technique in flicking the thrower handle, and once that is achieved the thrower is very repeatable. Over 100 throws I achieved an average charge of 25.00 grains with all charges in the 24.9 to 25.1 grain range.
I will leave the thrower set up and use it for future reloading of the 223 Rem.