I do not believe there is anything to gain by using it with a ball. These are thin at 0.025. Over the powder they will just fire form to the ball and this will bring the card away from the walls of the barrel and not seal anything while the ball goes down the barrel. Same in front of the ball, just wraps around it as it goes down.
If you are looking to just hold the powder and/or ball in place leading up to firing it, It'll do the job of holding your powder and ball in place, BUT, you will end up with an air gap around the back of the ball as it will not be fully seated on the powder. There will be some that say this is insignificant, and others that will warn of the potential hazards of not having the ball fully seated.
