I have a 460 S&W barrel for my T/C Encore. Given the cost of factory ammo, I consider this basically a "handload only" firearm. Given that, I just bought a bunch of 460 S&W brass and am using it exclusively. Given the jump from the case to the lands of the barrel, for my purposes I see no reason to use a reduced load in 45 Colt brass. For reduced loads, I intend to use a high bulk cowboy powder.
A note on handloading this: The Lyman manual indicates a minimal increase in velocity over a fairly wide range of H110 powder weights for the Hornady 240 gr XTP Mag HP. Given that, I just use the Lee hand dipper for charging the cases (with a WLR primer) and seat the bullet with a heavy roll crimp (using the Lee hand press). It is pretty quick to run up 20 rounds and seems to work.
BTW, with this load, the rifle (with the 20" barrel and aperture sight) does kick a bit. Subjectively, I put the felt recoil in between my 35 Whelen with 250 gr. bullets and my 375 H&H with 270 gr. bullets.