my tc hawkins .50 cal will only shoot the 370 maxi-ball well..i never tried sabots..

the powerbelt 295/348 also shoot great..all shot best at around 80 grs of 2f..

on hawkins, factory said you should use a long bullet..dont use maxi-hunters ,they are too short..

as for roundball,i never could get them to shoot until ROUNDBALL helped me on here..at 60 grs of 2f,at 50 yards,.490 ball,i can shoot in same hole with my RMC sights..i gave up on roundballs years ago in my hawkins but now, i use them all time..they shoot great out of 1-48 twiist..