I use .454 or .457 balls in my Uberti-made replica of the Remington and my Pietta-made replica of the 1860 Colt.
Some years ago I bought a few boxes of .457 balls for my .45-70 Marlin but didn't use as many as I planned, so I started using them for my cap and balls. Works fine. No strain on the rammer and accuracy is good.
I find no difference in accuracy between the .454 and .457 inch balls. However, when I drop down to .451 inch my groups begin to open and I get more flyers. I'll stick with the larger balls.
Incidentally, a .45-70 case will hold THREE .457 balls, with a dry-lubed Wonder Wad above and below the middle ball.
I made some up years ago to prank a friend, who had no experience shooting. With every shot, at 25 yards on a BIG bullseye (hits encourage confidence with new shooters), he saw THREE holes. The puzzled look on his face was priceless!
I also loaded the same three-ball cartridges in my 1895 Marlin, as a house gun. Figured the three .45-caliber balls would settle any account with a two or four-legged beast, yet not endanger the neighbors with too much penetration.
Never had an opportunity to shoot anything with it. Accuracy's fine out to about 50 yards --- all balls in a 9" paper plate. At 25 yards, balls cluster into 3 or 4 inches, sometimes less.
Heck of a day-ruiner!