I load it for a Casull I got back in the 80's when they first came out.
Cylinder dimensions are so tight, I have to clean any lead shavings off the exposed bullet for them to fit in the chamber.
I bought their Lyman mould at the time in 260g GCTC and recently I modified a .459 350g 45-70 that I cast to .452 and called Hogdon and Casull for load data. This puts the .454 into the .480 Ruger territory.
I can say, without giving out load data, that from my 7.5" barrel I chronographed the 260g load at 1875fps and that was BEFORE I loaded it up to max in the data. Impressive to say the least.