Abstract: A modified cartridge assembly including a projectile having a gas generator proximate its aft end. The projectile includes an aft closure having a cavity filled with gas generating material. The gas generating material is ignited around the time the projectile exits the weapon's muzzle. The gas generating material then burns while the projectile is in flight, spewing pressurized gas into the wake region immediately behind the projectile. The pressurized gas reduces the projectile's base drag.

Abstract: A modified projectile round which is configured to function with a propellant cartridge such as described in U.S. Pat. No. 7,004,074. The projectile assembly uses a High-Low gas pressure cartridge to launch the projectile. When the high pressure cartridge is ignited, hot propellant gases rupture a burst cup and shoot propellant gases toward the aft end of the projectile. The hot propellant gases impinge against a delay carrier located in the aft end of the projectile. The contents of the delay carrier are thereby ignited. The delay carrier includes one or more delay columns ultimately terminating in an igniter charge. The delay columns burn as the projectile is in flight. A specified amount of time later, the igniter charge ignites an ignitable payload—such as a marker flare candle.

Abstract: A modified gas delivery cartridge. A conventional straight-sided brass cartridge case is primed and then filled with solid propellant. A burst cup is then inserted in the case mouth. The burst cup is embossed with a cross or other shape to promote predictable rupture. Once the burst cup is in place, the upper edges of the cartridge case are rolled over the burst cup. In operation, the propellant is ignited to produce pressure within the sealed case. This pressure builds steadily until the embossed cross in the burst cup ruptures. The propellant gases are then vented in a metered fashion through the ruptured burst cup. However, the burst cup is retained by the case so that no solid object escapes the high pressure cartridge. In addition, by carefully designing the shape of the burst cup and the components surrounding it, it is possible to create an efficient expansion nozzle to better meter the propellant gases.