Dave, most Walkers and Dragoons .44 cal take the .457" ball because of chamber size. uberti Rev chambers are sized to take .454 or can squeeze .457 in them.
Euroarms take a .457 ball, Pietta take a .451 store bought or Lee molded
.452" ball or some may take the .454" ball.
.36 cal are the same Pietta .375" ball or Uberti a .380".
Is best to measure your chambers before buying. Or get the .454" if guessin'.
SG