DUAL SPHERICAL POWDER FOR 12.7 MM CARTRIDGE WITH ARMOR-PIERCING INCENDIARY BULLET Russian patent published in 2021 - IPC C06B25/24 

FIELD: gunpowder.

SUBSTANCE: invention relates to the field of production of spherical gunpowders for small arms. Dibasic spherical gunpowder for a 12.7 mm cartridge with an armor-piercing incendiary bullet includes cellulose nitrates containing nitric oxide, diphenylamine, centralite I, dinitrotoluene, ethyl acetate, moisture and bound graphite. Additionally, the gunpowder contains nitroglycerin and centralite II with the following ratio of components, wt%: nitroglycerin 10.5-12.5; centralite I and II, in total 3.0-5.5; dinitrotoluene 1.5-2.5; diphenylamine 0.5-1.0; ethyl acetate 0.1-0.5; bound graphite 0.1-0.3; moisture 0.2-0.4; cellulose nitrates with a nitrogen oxide content of 210.0-214.0 ml NO/g - the rest. Gunpowder has a bulk density of not less than 0.95 g/cm³ with the following mass ratio of fractions,%: 0.7-1.25 mm - not less than 80, more than 1.25 mm and less than 0.7 mm, in total - not more than 20.

EFFECT: required ballistic characteristics are provided: the average speed of the bullet is not less than 810 m / s, the maximum pressure of the powder gases, the average, is not more than 316.3 MPa (3100 kgf/cm), the spread of the speed of the bullet in a series of 10 shots is not more than 40 m per sec.

1 cl, 1 tbl