50 yard shooting with that load might work real good. As long as she does the high percentage shots. You might want to shoot a few off to make sure that the rifle is still accurate with that reduced load. Powerbelts can be a strange bullet.

Otherwise I would suggest she try a 200 grain Shockwave .40 caliber or even a 300 grain XTP with that reduced charge. But I am sure you know what your doing and what your wife can tolerate. Good luck to her.