If you're shooting 45 Colt loads 2400 works great as does H110, 296 is the very same powder. AA9 is also a good powder for heavy loads. A favorite of many 45 Colt shooter is 20 grs of 4227 with the bullet you mention. For a little lighter load in the Colt try 9.0 grs of Unique, I've taken several deer with that load. And is this uncertain time a pound of it goes a long way.
In the 454 Casull H110 is the go to powder for most shooters, just don't shoot a reduced load! I have a lot of Longshot powder & it's one of my favorites in several handgun calibers from 9mm up to the Ruger 480.
Dick
