Semi,
First of all thanks for sending me the literature on the "Dutch Schoultz System". It is interesting reading if nothing else. I'm sure if a ball was really significantly odd it would make some difference. Have you tried cutting the patches at the muzzle to make sure the ball was perfectly centered in the patch?
Anyway, the system gives a person some ideas of things they can tinker with and most muzzleloading people like to tinker. Whoever wants the literature next just send me your address and I will get it to you.
Art
PS My balls are about the same size and weight