Precision forged cartridge case

A segmented die assembly for cold forming the head of a rimless cartridge case comprising a die case with a tapered bore and segments slidable in the bore, the segments in a closed position bearing against the die case bore and collectively forming an internal annulus that precisely determines the finish shape of an ejector groove on the head that includes a radial side, a cylindrical bottom and a truncated conical side facing the radial side and spaced from the radial side by the cylindrical bottom.

A trimming apparatus for producing a uniform sheared edge on a tubular work piece in a multi-station cold forming machine comprising a collar with a bore adapted to slip over the work piece, the bore having a sharp peripheral edge, a tool with an end sized to fit in the work piece, the tool end having a sharp edge, and a mechanism to develop radial and angular motion of the tool relative to the collar, the tool and collar edges during such radial and angular motion being arranged to shear the tubular work piece to sever a ring therefrom and produce said uniform edge.

A set of tools for use in a progressive forming machine to make cartridge cases with finished ejector grooves, the tools being receivable in die cases and opposing punch holders arranged in workstations uniformly spaced along a common plane, the tools including a punch and die set to upset an elongated blank cut from wire stock into a circular blank with an outside diameter greater than its length, punch and die members to form a tube on one end of the blank and a primer pocket on an opposite end, a draw punch and die set to draw the tube into a thin wall, and a segmented die with at least four segments arranged in a circular array and a cooperating punch to upset the material of the primer pocket to make a finished ejector groove.

A cut off device for trimming the mouth end of a drawn cartridge case comprising a cantilevered pin sized to fit into an untrimmed mouth of the case and having a sharp edge at a distal end, a support for carrying the pin as a cantilever as the pin extends with its sharp edge into the mouth, a mechanism to move the pin radially outward and in a path around the center of the case such that it cuts the wall of the case to remove a short length of the wall to form a precision case edge, and a collar adapted to fit closely around the exterior of the mouth end of the case to cooperate with the pin in the cutting action of the pin.

18-23. (canceled)