my lyman 55 powder measure doesn't throw consistant charge weights with small charges, 2-10 grains. i now have a bonanza bench rest measure and a herters model 40, the surface area of the charge hole is a lot smaller than the lyman and circular rather than rectangular, and throws more consistant charge weights. does the size and shape of the chamber opening have an affect on how the chamber fills consistantly and how the powder is scraped off the top when the rotor turns?

I don't know the answer to your question, but I am having the same problem with my Lyman. I set it last night and it threw charges of IMR4064 from 46.5 to 47.3 depending on the pull of the handle. It threw more when I let it sit for a while. Go figure. I was thinking about the Redding or Lee.

larrys; thanks for the reply, i was wondering if others had a problem or just my technique. the bonanza measure is consistant but must be clamped to a shelf and the venier scale still hasn't been translated. looking at a hornady measure, the redding is too much to satisfy my curiosity.