The new Norma load (9,3x62/325 gr.) actually comes very close to advertised velocity of 2300 fps using short barrels and I think that with longer barrels this will be exceeded.

The main difference between 9,3x66 and 9,3x62 is in pressure levels. If you increase the level of 9,3x62 to that of x66, the difference is next to nothing.