Does anyone know how to use these things? Do I place the bead level with the top of the horns or in the tiny little knotch at the base of the "U" in the horns. Thanks.

place the front sight into the bottom notch. The horns purpose is to help focus your gaze while sighting.

Never thought of it that way. Your probably right. Any time I've ever tried to use them that's all I could see, so they must be doin there job just right. I've got a little box full of buck horn and semi buckhorn sights. I intend to cut the flat spring at the dovetail, clean up the edges and use them for blanks on my rifles that ALL have peeps of some kind. Pepe Ray