I normally just cut them off and then bore out the end. You have to be very careful drilling them out as they will catch and either crak the horn or lock up your bit. Normally, I start them with the drill press and use a dremmel or the foredon to finsih up and then ream them to size with a drill bit by hand. Takes longer but I have cracked a few horns trying to drill them out all the way.
If you have one that really solid you will have your work cut out for you but go slow and it will work.
If you have one that is too thin to get a tone board in, you can laminate a pice of wood on the end after turning it close to shape and then sand it by hand to contour it. I do that with quite a few horns.
This one has a piece of black wood laminated to the end
I used Devcon 2 ton epoxy to laminate them together and filled the space between the wood tenon and horn. Makes for a very solid connection. I would not use 5 minute expoxy though as it is not water proof and if it gets damp or wet will turn to soup on you.
Al @ THO
