I used 451 because it’s all I have. And they were 140 GR not 160.
I think??? That the balls compress slightly. My guess is that your 454 would work better. They are very soft lead so don’t push them very hard.
By the way, Speer #10 has a load for the 454 140 gr round ball for the LC. But not for trailboss.
Tell me another powder and I will give you the max min load.
http://www.castpics.net/LoadData/Rou...ll%20Loads.pdf