Metalguy,
My m46 is also untouched and like Daryl, I too opened up the notch in the rear sight. My current load is the Speer 270 grain bullet propelled with 48.0 grains of RL15. Velocity is unknown at this time because my chronograph decided to go on the fritz after almost 30 years of use.
My load with the original sights (modified as described) is zeroed at 200 yards. At 100 yards it hits 2 3/4" high.
The same load with the Privi 285 grain bullet is dead on at 180 yards and only an inch low at 200.