Abstract: The invention is an improved solid propellant grain, wherein the solid prllant grain is structured to provide a programmed method and system for splitting the solid propellant grain at a programmed moment to provide an increase in the burning surface. The programmed-splitting of the solid propellant grain provides improved ballistic performance of guns, which yields a higher muzzle velocity for a given projectile without increasing the maximum pressure exerted on the gun chamber. The improvement consists of embodiments that are a plurality of slits of various configurations through the longitudinal length of each grain of solid propellant. The improvement includes a structure to delay end burning of the grains until the longitudinal exterior surface burns sufficiently to split the grain into a plurality of sections at a programmed moment when the increased burning surface is desired to occur.

Abstract: A propellant charge igniter is provided with a metallic igniter tube which is consumed along with the main propellant charge. The combustible igniter tube is flexibly attached to a conventional primer head. An elastomeric tube, a springreinforced tube, or a tube impregnated with a wire mesh can be used to achieve a flexible connection. These tubular elements may be bonded to the primer head and igniter tube, or mechanically attached by means of threaded couplings which are crimped over the elastomeric tubing.