Is the Lyman #55 the cure for what ails me?

[k4swb]

Thanks for your thoughtful response. I have never read about a double tap at both the top and bottom as being required or even a good thing.

Double tap at the top ensures everything gets out. Double tap at the bottom makes sure everything gets in.
Single taps work as well but I just developed a habit of the DTs.

I guess I'm just lucky in that I've never needed a baffle.

 

[thomas15]

I use a baffle and I have installed the small cylinder in the measure.

The thing that confounds me most is this propensity to drift upward. After 30 throws and the darn thing is 2 gr. higher than when I started! What could account for that?

2 grains is a lot of variance. I would check your powder scale with powder scale check weights. I suspect there is a problem with the scale not the powder measure.

 

[rfwobbly]

Thanks for your thoughtful response. I have never read about a double tap at both the top and bottom as being required or even a good thing.

Yes, the 'double knock' helps completely fill and empty, but the main thing it does is supply vibration into the body of the PM. It's the constant and consistent vibration that makes the powder settle to a uniform Density. From uniform Density comes uniform powder Weights.

BTW, it has been suggested to me that the best powder measure extant is the Dillon. I'm not certain which would be best for my small measures (4-20 gr.)? But one thing is certain, I'm not planning to purchase a Dillon press so I'd need something that can function as a standalone. Is there a standalone stand for the Dillon measure?

The Dillon PM is very good, but it's a case activated measure. It can be fitted to any press that uses 7/8-14 dies, but it cannot be used as a standalone, like your Uniflow.

What's so special about the Dillon is a set of cams that allow the shuttle to fly back with the same force each and every time, no matter how fast or slow you operate the press. There again, the constant and consistent vibration makes the powder settle to a uniform Density.

The hard part is not mounting the PM to the non-Dillon press, but rather triggering the cams. If you defeated the cam mechanism, then I suppose the Dillon PM would be no more accurate than any other volumetric measure.

Hope this helps.