If you want to put bigger balls in your C&B, get the chambers reamed out to take them. Chambers on mine are reamed to 0,454 and I use 0,457 balls. That way, when the actual 0,454 ball goes through the forcing cone to a 0,452-0,454 bore, it fits like it should. That is how a C&B should be set up. It is also how Ruger OAs are set up.
Lars