The Cast Performance 360gr. GC and 27grs. of H110 will yield 1425fps out of my FA six in. revolver. This load is pleasant to shoot and is safe in the Ruger and Taurus. If you have a chronograph and an FA revolver, You can increase the powder charge SLOWLY, until this bullet is being pushed over 1600fps--only out of an FA revolver.
This isn't a dig, but have you ever handled a FA? I'll defer this to the guys that have done destructive testing but I believe the gist of the story is to play by the rules with the non FA guns. There are guys shooting >300s at over 1800fps with the 4 3/4 inch barrels, I doubt you would want to run the 6inch that warm.I don't see why the FA would be any stronger that the Taurus RB.