Abstract: An obturator having redundant surfaces for sealing between a projectile and a gun tube, where the obturator has at least one gun tube side cannelure. At least one projectile side cannelure is located opposite to the at least one gun tube side cannelure, where the at least one gun tube side cannelure is conformed to seal around the projectile. A tail protrudes from a rearward end of the at least one gun tube side cannelure, where the tail makes an interference fit with the smooth gun bore to make a low pressure seal.

Abstract: An improved geometric propellant loading configuration for high velocity, large or medium caliber projectile ammunition is disclosed. The propellant system includes several mutually contiguous extrudable stick shapes that in concert result in highly efficient use of propellant load space. The system reduces loading, assembling and packing (LAP) labor and overall cost, yet provides a dense pattern to increase propellant load and high perforation to improve burning progressivity over prior stick loads and more reliable and improved ballistic performance.

Abstract: A propellant load arrangement for a large caliber ammunition cartridge case accommodating a ballistic projectile includes a plurality of relatively flat shaped segments of propellant assembled face to face in an ordered arrangement. The faces of the segments of the arrangement are optionally parallel or perpendicular to the longitudinal axis of the cartridge case and essentially occupy the entire available propellant volume of the case. The outer peripheral geometry of each segment of the ordered arrangement is shaped to match the corresponding cartridge casing interior geometry and each segment of the ordered arrangement also has a shaped central interior recess opening as required of a geometry matching the corresponding geometry of any interfering internal cartridge part and any projectile geometry present. Relatively cool-burning segments can be combined with relatively hot-burning segments in stratified arrangements to provide a cooler boundary layer and reduce tube erosion.

Abstract: A control system compensates for temperature dependent propellant burning characteristics by adjusting the chamber volume available to the propellant in an ammunition round. The control system includes a control tube housing, a piston assembly slidably mounted relative to the housing for movement through a drive stroke and being drivingly coupled to a trailing end of the projectile, and components responsive to the temperature of the round for adjusting the length of the drive stroke of the piston assembly in proportion to the temperature and thereby adjusting the position of the projectile and volume of the chamber in proportion to the temperature of the round.

Abstract: A variable stroke projectile postioning system compensates for temperature by adjusting the volume of a munition chamber which communicates with a projectile and contains a propellant having temperature dependent performance characteristics. The projectile positioning system includes method and apparatus which perform the operative steps of moving the projectile at a forward end of the chamber where its position defines the volume of the chamber, measuring the temperature of the propellant charge to be placed in the chamber for firing the projectile and having temperature dependent performance characteristics, and controlling the moving the projectile in response to the measured temperature of the propellant charge to cause the projectile to be placed at the exact position where it adjusts the amount of chamber volume to provide the correct degree of compensation for the measured temperature.

Abstract: A temperature compensating ballistic control tube system for varying the volume containing primary propellant, for the purpose of affecting the effect of the propellant on the projectile in order to compensate for the effect of ambient temperature upon the performance of the primary propellant. The volume containing the primary propellant is changed by pushing the projectile away from the casing containing the primary propellant, down a gun bore by a piston of the ballistic control tube. The piston, pushing the projectile, is moved by an ignited secondary charge in the ballistic control tube. Electronic components detect initial movement of the piston and projectile and, after a certain delay, ignite the primary propellant thereby ejecting the projectile from the gun. A typical primary propellant, within a given volume, is temperature senstive, that is, it provides more force to the projectile at higher temperatures.