I'm trying to make barbell loadable atlas stones that have accurate weights. Like, say, 50lbs, 100lbs, and 200lbs. It's hard to accurately calibrate the weight of atlas stones I would imagine as their weight goes down as the cement dries over time, but certainly it can be estimated vis-a-vis the volume. Anyway, that's the weeds, ideally I'd make a custom mold with 50mm diameter cylinder passing through the center, but what I have is a solid atlas stone, and I'm thinking I can bore a 50mm hole with a masonry bit I actually already have with my large drill press, but once the hole is drilled, how then can I calibrate the weight to be heavier or lighter to have precise standard weights in 50lbs, 100lbs, and 200lbs?
Just in case it's not clear what I'm describing: