Patent ID: 7802520

Claim:
A cartridge assembly for reducing the base drag of a projectile in flight, comprising: a. a low pressure case, having a base and an open end; b. a high pressure cartridge inserted within said base of said low pressure case, having a closed first end, an open second end, and a continuous side wall running between said first and second ends, thereby defining a hollow interior; c. propellant, contained within said hollow interior of said high pressure cartridge; d. a burstable sealing member sealing said open second end of said high pressure cartridge, thereby closing said hollow interior within said high pressure cartridge; e. wherein said low pressure case includes a charge casing surrounding said high pressure cartridge; f. a projectile assembly seated in said open end of said low pressure case; g. wherein said projectile assembly includes an aft closure having an aft opening; h. wherein said aft closure includes a volume of gas generating material sufficient to inject pressurizing gas into the wake of said projectile assembly, through said aft opening, for a substantial portion of said flight of said projectile; i. wherein said low pressure case further includes a charge vent hole positioned to direct hot propellant gas from said high pressure cartridge toward said aft opening in said aft closure; j. said gas generating material being contained within a cavity in said aft closure; k. said aft opening lying at the aft extreme of said cavity; l. said aft closure including a forward extreme including a bulkhead; m. said bulkhead opening into an output allowing fluid communication between said cavity and the area forward of said bulkhead; n. an igniter charge located proximate said output opening; o. an ignitable payload located forward of said bulkhead and configured to be ignited by said igniter charge, said ignitable payload having an interior cavity; and p. a piece of ignition material having a forward portion and an aft portion, said piece of ignition material being located within said interior cavity in said ignitable payload, with said aft portion of said ignition material being proximate said igniter charge.