Recently bought a three screw 357 that shoots about 3” high at ten yards with the rear sight bottomed out. This is with everything from mild 38s to hefty 357 loads. Bullets ranging from 125 to 170 grains.
3" high at 30 ft. is perfect if you're talking a 6 o'clock hold on a 6" bullseye. The reason the different loads don't change is there isn't enough resolution at 30 feet - you're too close. What it does at 25, 50, and 75 yards is more important. Unless you discover a problem farther down range I'd leave it alone.
