I'VE Done a lot of reloading or the .454 in a Ruger SRH, and found the the SRH seems to llike heavy bullets at full velocity. I've been able to get 250 gr bullets to shoot min. of a pie plate at 100 yards, at a velocity of 1250 fps (avg). This is my deer hunting load. It is very devestating on deer at that vel. using 250 gr XTP bullets designed for the 45 colt, not the Mag XTP's. For heavier game I have reloaded 310 gr cast gas checks which shoot 1 in. groups at 50 yards using 4227 powder at max velocity according to Lyman book.
The reason I bought a .454 in the first place was because my .45 colt when I increased the velocity above 1000 fps would shoot eraticly so with the .454 I load it light and its a real pleasure to shoot at about 1250 fps and .250 gr bullets.
Mike