457 on the round bally. Hornaday makes one just for the ROA.
Dick Dasdardly has a conical mold in his big lube bullets. Mine cast out around 210 grains and I throw them thru my star sizer at .454 with SPG lube. They work great. There is a small rim at the base of the bullet so you can use them in 45 colt cartridges, scofield, and even in the 45 Auto. These can be sized easily 452 for colt cartridges in my vaquaros, 452 in my 45 auto, 454 in my ROA