CARTRIDGE Russian patent published in 1997 - IPC

FIELD: multifiring noiseless small arms. SUBSTANCE: cartridge uses a bullet with a steel slug, lead jacket and bimetallic envelope, cartridge case having a slope, flash igniter and propellant charge. Optimum overall dimensions of the bullet and cartridge case are as follows: bullet length -(4.5 to 4.6)d; length of bullet head - (1.7 to 1.9)d; cartridge case length - (4.1 to 4.3)d; cartridge case slope length -(0.17 to 0.18)d; length of cartridge case bottle-shaped section - (1.1 to 1.15)d, where d - bullet caliber. Momentum of propellant charge -(45 to 55)kgf/sq.m; charge density - (0.5 to 0.6)g/cu.cm. Bullet weight factor - (20 to 24)g/cu.cm. EFFECT: enhanced efficiency.