350 legend with 9mm 124 Gr. RMR JHP (MPR NUKE)

Usually hollow point bullets made for handgun velocities over-expand when pushed faster. My guess is that at a minimum you would get jacket/core separation which would decrease penetration. In addition the petals would probably be shed by the core further reducing penetration and the size of the crush cavity. The best way to find out would be to fire some into water jugs. That would give you a worst case scenario.