I have my wife and 3 kids all into cas. We shoot NRA CMP, IHMSA Silhouette, CAS, and 50 bmg.
I have a Dillon 650, an RCBS progressive, and 3 single stage units and occasionally have had all going at once. The kids like loading and shooting.
I have a production casting operation going and they do that too sometimes.
As far as rounds on hand... I measure them by the bucket full. 2 or 3 on hand at any time time.