Slug for a shotgun shell

Claim 1

A slug cast from a single piece of metal for use in a smooth bore shotgun, said slug comprising a truncated conical body having a flat circular front face and a parallelly disposed flat rear face, the diameter of the front face being slightly less than the diameter of the rear face, a series of circumferentially spaced, straight, fluted, rectangular shaped vanes projecting outwardly from the side wall of the body with the vanes being separated by channels, each vane extending obliquely between the front face and the rear face of the body with the top surfaces of the vanes describing a truncated cone, the pitch of the truncated cone of the vanes being steeper than the pitch of the truncated cone of said truncated conical body whereby the height of the vanes decreases from the front face to the rear face of the slug, said vanes move in interfering contact against the bore of the shotgun to impart a rotational motion to the slug as it moves therethrough, each vane further having a front tip that extends outwardly from the front face of said body and which terminates in a chisel point edge, a blunt nose projecting forwardly from the front face of said body a greater distance than the chisel point edges on said vanes whereby the nose strikes a target before said chisel point edges, an annular ring at the rear face of the body that has an outer diameter substantially equal to the outside diameter of the cylinder described by the vanes whereby the ring closes each channel between the vanes, and said body containing a blind hole passing inwardly from the rear face to a depth that is greater than one-half the axial length of the body whereby the slug has a nose heavy configuration.