Raining blood expert

As probably posted here many times but the last one I could find was a year ago. I’ve visited this on and off for a few months now. I beat every other song on GH3 Wii on expert and just cannot get through mosh 1. It is insane that I can beat other songs but during mosh it almost feels like the hammer ons just don’t register. This is insane. Any tips and help please would be appreciated.