"The best guess I've heard is that it's powdered gelatin, intended to be a binder (and not a very good binder at that)."
they have a new one that has a liquid binder they made for the primer making die https://recoilstore.com/prime-all-center-fire/
my muzzle loading buddy hasn't tried it yet...he is my only source of info...except y'all!!!
thanks again I am learning tons