Looking good, there Gander - however if there is fouling buildup, ANY buildup - the bore is either pitted, or your combination is too small in diameter - thus - thicker patch or larger ball is required - that is, if you want it to shoot as well as it's capable of being shot.
I've never seen a .50 that didn't prefer a .495" ball - with a .020" to .0235" patch as well. Of course, it's your call.