Atlesdt to get a good flow from the wood to horn I like to pre taper the horn after drilling the hole. I use the round front edge of the belt sander for this as it gets a good taper and leaves fluently of meat to work with to build up a string nock and decorate however you please. The best part of horn mocks is they don’t need a perfect fit to work. The glue will fill the gaps and of it happens to pop loose the pressure of the string keeps it pulled into place.
Kyle