Yeah, but when you determine the weight of your dime, and put it in a little baggie, it ain't gonna change...
And Bart's 68 grain benchrest bullets weigh 68 grains, give or take a little (and the "give or take a little" comes from a scale that isn't sold by Midway... one of the first thing that one learns in benchrest is that _everything_ has tolerances - some are just smaller than others), and are perfectly adequate as test weights.
Do you have a "smaller" chamber setup for your uniflow? I have the micrometer dealie on mine, and just never could get into it... So I bought a Harrell...
Let's see...
Two Lee Auto Disk measures
Two Lee Pro measures
One RCBS Uniflow
One Harrell premium benchrest
And I've got two Lee scales, a couple of RCBS scales, a Dillon that Oleg, and now Tamara, has on Long-Term-Permanent-Loan, and an electronic gizmo that hates going outdoors. And I've got the ?g scale down in the basement...