It's been my experience that the diameter of the Elk hair needed to form the wing is too small or narrow to be hollow. You are basically tying in the tips which are solid. Some say use the hock but that is generally solid and very stiff, which means the wing will spring back to a "flat" profile, tips out over the eye. Deer works best IMO, look for even, short tips. You will be very lucky if you find a good section the first or second time you buy some. Also, track the piece, that is to say not all of the patch will be useable. I have some patches that have trails clipped through them. An entire patch rarely has all the properties you are looking for.