Abstract: The process for dimensioning the neck of a used cartridge casing comprising providing an extrusion ram having a head and shank, inserting said head through the aperture of said neck, said head having a diameter slightly less than the diameter of said aperture, applying substantially uniform pressure circumferentially to the outer surface of said neck to reduce the inside diameter thereof to slightly less than the diameter of said head, withdrawing said head through said aperture while retaining said pressure on said outer surface of said neck, thereby causing excess metal in portions of said neck to extrude axially toward the outer end thereof, and thereafter trimming excess of said extruded metal from said outer end.