I've used .451s in a Pieta 58 remington for years with no problem. I've also used them in a several other revolvers and they are okay if they cut a ring as you load them. Try one cylinder at a time. If they load with a cut ring or significant resistance you are probably okay. If they go in easily, then I would definitely move up to .454s. I have a Rogers&Spencer made by Euroarms and if needs .457s. Even .454s are not a tight fit in it. Two things can happen with too loose of a ball. One is you may get a chain fire of other chambers in the cylinder, the other is they may move forward under recoil of and lock up the cylinder. Neither is fun.