Depending on who makes the revolver, the size of ball will vary. For instance I shoot a F.L.Lippeta (also called Pieta)sold by Cabelas. They shoot a .451 ball with 25-30 grains of 3f powder and a #10 cap. The Rugers and the Colts and I believe the Ubertia shoot a .454 ball and can take a stronger charge.