Ammunition casing having a cannelure with step
AssigneeShell Shock Technologies LLC
InventorAnthony Viggiano
Life of this patent
Estimating the term…
Abstract
A casing for an ammunition cartridge comprises a sleeve portion and a base portion. The casing may be two-piece, where the base portion is secured to the sleeve portion by means of a nipple having a flared end. The base portion comprises a cannelure that extends lengthwise from a flange. The cannelure, which is preferably curved, is deeper than a conventional cannelure and thus the casing weight is reduced. The cannelure has a step that is adjacent the flange, for limiting inward travel of the lip of a hook of the bolt of a firearm. Alternatively, a casing may be a one-piece casing, wherein the base and sleeve are integral.
Claims9
A casing for ammunition used in a firearm, the casing having a lengthwise centerline, a proximal end having a recess shaped for receiving a primer, and an opposing distal end comprising a mouth for receiving and holding a projectile, the casing comprising:
- a sleeve portion, for holding a quantity of gunpowder, the sleeve portion having a distal end characterized by said mouth, and an opposing proximal end from which runs lengthwise a cylindrical exterior surface having an associated diameter;
- a base, having a distal end characterized by a cylindrical portion that is securely mated with or integral with said proximal end of sleeve portion, a proximal end characterized by a flange having a first side annular flange surface that forms at least a portion of said casing proximal end and an opposing second side annular flange surface that faces toward the distal end, the base further characterized by a cannelure situated between the flange and the distal end of the base, the cannelure characterized by
- a first cannelure surface portion that faces distally and comprises at least a portion of said second side annular flange surface;
- a second cannelure surface portion that is either contiguous with said first cannelure surface portion or spaced apart therefrom by a groove, the second cannelure surface portion extending lengthwise as a step having a diameter which is less than the diameter of the flange;
- a third cannelure surface portion, running inwardly from the second cannelure surface portion toward the casing centerline along a plane or a curve, and then extending lengthwise cylindrically or curvingly;
- and,
- a fourth cannelure surface portion, running outwardly from the third cannelure surface portion and away from the casing lengthwise centerline, the surface portion having either a conical or curved shape.
Dependencies are inferred from the claim text.