Before you can safely reduce spring rates, you must confirm that the gun is in spec and preferably on the tighter side of tolerances. Endshake and headspace at minimum, firing pin protrusion at or very close to max spec, transfer bar dressed and trued, hammer nose recess adjusted to ensure that the transfer bar gets maximum contact, yoke straight, cylinder running true, timing corrected, burrs and casting/machining artifacts cleaned up as appropriate. Then the careful polishing to smooth mating surfaces without adversely changing dimensions/fit. After all that, you will find that the smoothness of the action is so much better that the trigger pull is lighter and will seem less that it really is. It will usually be safe to try reduced power springs at this point, though you must always check for proper function and ignition reliability. You may not want to replace the springs after you feel a properly smoothed action.