The early .44's took .451's, then the chambers were enlarged by most makers and .454 became the standard. Then the ROA came out and required .457 and Uberti made their chambers bigger or vice versa. Some people do use .451's in Pietta but I have had them move under recoil so I went with .454 and now have a Dragoon that needs .457 so may just stay with them for everything.
Neat, thanks.
I had no problems with 451 in brass guns I started with, but assume they were too light of recoil to do much.
I'm casting now and went middle of the road so I make .454.
I tried some 457, and my chambers in all but 2 guns are hard to seat them. One has chamfered mouths that must swage it down, the other is my walker, it eats them fine, stiff, but fine. 454 work ok, 451 no go.