You might find your point of impact shifts low with lighter bullets. I used to own a Model 14 with an 8-3/8" barrel that shot to the point of aim with 148-grain wadcutters but four inches low at 25 yards with 110-grain hollowpoints loaded for woodchuck hunting. The rear sight could not be adjusted high enough to compensate for the shift but another rear sight blade that Smith & Wesson installed for me worked for both loads. You gun, however, having no adjustable rear sight might not be as easily fixed.

Ed