What we used to do with stag horn in stickmaking, was to drill out the soft core, to the "bone" edge. Then mix pure araldite and coat the inside surface of the hole. We then coated the steel bar with pure araldite. Then we mixed more araldite and mixed into that, horn dust or wood dust, like a paste, and we packed that into the hole, then pushed the bar into that and let it set. There is no way of getting it back out. Its the same principle for the knife tang. Two things to remember though,- you must drill a tiny escape hole for the air when you pack the hole with the "paste", and you must ro