Got a Redding Benchrest powder measure and stand from my shooting buddy Steve on Sunday. Like so many things on Steve's bench, he's not used them in a while, having replaced them with better stuff, like an Auto-Trickler. So, I brought it home, took it apart and cleaned it up. The anti-lash assembly was a surprise to me, never having worked on one of these before. Took a minute or two to figure out what it did and then how to reassemble. Pretty easy actually.
The micrometer adjustment is truly machine shop accurate for what you are doing. But, and this is a big but, I only have the rifle insert for the drum. I did not measure it, but it is close to 3/4" in diameter and that is a large surface area to be measuring tenths of a grain. Couple that with the relatively coarse thread, which looks like it is about a 24 TPI and you have a very hard time adjusting 0.1 gr out or into a load. What was very nice was I had tried it out dropping 17 gr of 2400 and I simply dialed in 15.5 from 17 using the micrometer and first drop was 15.4. That's impressive.
Steve said he has another that he was going to give me for parts. If I'm lucky, it will have the pistol insert which I expect will be a much smaller diameter piston making small adjustments to the load much easier. If not, then I might machine a new adapter and use the same thread pitch so I can use the micrometer from the rifle adapter. According to the Redding description for the measure, one comes with only the rifle adapter and another model comes with both. The pistol could be sitting somewhere on Steve's bench if there is not one in the other measure he said I could have for parts.
With the rifle adapter, I found that the load varied +/- 0.1 gr. I ended up measuring each charge for 20 round since I'm doing some more testing tomorrow.
I also need to revisit my RCBS Uniflow. I was looking at the new ones and they are different. Seems they changed the method of adjustment, making it more micrometer-like. I wish I had the ability to engrave numbers. Making a micrometer adusting drum for the Uniflow would be a pretty easy. But I could not bring my self to hand engrave with a vibro-engraver, the numbers. I can cut the lines on my mill with my dividing head. Maybe if I did the OD machining first, cut all the lines on the drum first, I could then stamp the numbers and once that is done, machine out the inside. Hmmmm... we'll see.