Could it be that brass is dense enough compared to the medium used to measure capacity that the same volumetric change in materials produces a significantly different percentage change of weight for each of the materials?

Thought experiment: Suppose I could add brass material to the inside of a 223 case to double its weight. A change of 100% which would then cause a decrease in capacity. Does the capacity go down 100%? No, it doesn't.

Last edited by mathman; 08/23/23. Reason: added text