Martin- the whole idea of the cupped wad, is to hold the ball in the middle of the barrel which will prevent the ball from touching the side of the bore. Thus, it will be launched without or with little spin (most wads take on a slight spin, apparently), but that spin will be radial, around the bore's axis tending to increase accuracy, not as in a climbing or dropping spin as can happen if an unprotected ball rattles down the bore. That bouncing, erradically spinning innacurate ball emulates the old round ball loads, so-called punkin-balls of yesteryear, not the much more accurate modern round ball loads as we now know to make them.