Get an adjustable powder measure. Powders will vary in weight depending on relative humidity and lot to lot differences. It's very difficult to say xx ccs of Unique from 1989 weighed in Oregon will be the same as xx ccs 2010 Unique measured in So. CA. I made some custom dippers for my powders/loads when I lived in So. CA in the early 90s which weigh differently now in rainy Oregon. My suggestion would be to get an adjustable powder measure and set it each time you use it, checking it against a beam scale...
My Anchor is holding fast!