I think the old measures were all pretty small capacity by today's standards. The small charge was probably the target shooting charge and the double charge was for hunting. For the most part the everyday shooter did not have quite the interest in guns that the enthusiast does today, so they weren't as concerned about powder measurement down to the grain. They just wanted something that worked. Personally I would not want a charger that required double charging since I have fired several shots that were just short started, and at least twice loaded a powder, patch, ball, powder, patch, ball. It doesn't take a whole lot of distraction to cause that to happen, and most of the time when you take a flintlock to a range there are plenty of distractions. First everybody wants to watch and ask questions, and usually there is somebody down the line with an "earschlippenlouderboomer"