I've loaded up a bunch of RB SR4756 loads using a .722" WW ball, cup-wads for centering the ball, card base wads, etc. with a folded crimp. I'll try them in my old Mosberg pump for starters, with the choke turned to fit the ball and seem what happens. I suspect velocties in the 1,450fps range according to the Lyman data I used.
: Of course, loading for a rifled tube can be a bit different. I suspect with the accellerating ball held by "G" force in the base cup of a wad, that it would be spun by the rifling/wad fit and need not touch the bore itself. This would also reduce pressure over the smae load with a groove diameter projectile.