Re: A new members questions
Hello Mac, welcome aboard.
One potentially dangerous problem with percussion revolvers is chainfires - the flash from one chamber going off might get past the lead ball in an adjacent chamber and cause it to go off too. You can read some of the other threads in this forum for more discussion on the topic.
The .454 balls were probably recommended to reduce this risk. You can probably get away with using .451 balls, but it would be wise to put some lube in front of the loaded balls to seal up the chambers as best as you can.