All patches fray around the edges from the muzzle blast.
: The reason for the thicker patch, is to hold more lubricant so the fouling stays soft and allows continuous shooting without having to wipe the bore. This may or may not require a smaller ball. In all bores with .010" deep rifling I use a ball that is .005" under bore size with a .020" patch. In every gun I've tested, they've all shot poorer with a thick wad. A single card wad like an over shot card, .010" thick can be used to protect the powder from lube and has shown less effect on accuracy for hunting purposes.
; The most important physical aspct of your gun are the muzzles. The crown must be radiused to allow easy seating of the ball. Your thumb, with 320 grit emery cloth and some oil or WD40 is all that's needed to make a perfect crown on the muzzles. If properly radiused, the ball/patch can be smacked down flush with one blow of your fist. Of course, the starter's shaft is held in the palm, pointed upwards) A flat spot on the starter knob does the smacking on top of the ball. There will be a very slight flattening of the sprue of the ball, but very little at all and it does not in any way effect the shot's accuracy. Loaded this way, my 14 bore makes 1-1/2" or smaller groups at 100 yards for 5 shtos, each every time I shoot it off the bench at that range with it's open, shallow "V" and bead Express sights.