Still have a bunch of Black Talons. They open up in a similar manner.
All copper is a bit lighter than lead. Corbin has developed most of the defense bullets in use today.
Corbins.com
Yes no one is volunteering to be shot by this ammo.
Yes the expansion is impressive but given that you are going to give up mass and thus pounds of force by replacing lead with copper what are the advantages of this ammo over standard safety slugs.