MULTILAYER PAPER CARTRIDGE CASE FOR SMOOTH-BORE GUN CARTRIDGES Russian patent published in 2024 - IPC F42B5/26 

FIELD: weapons and ammunition.

SUBSTANCE: invention relates to ammunition of smooth-bore weapons and can be used for firing from smooth-bore weapons of central fire. Multilayer paper assembly sleeve with bottom wad height equal to the height of the metal base with accuracy of ± 0.5 mm, consists of a paper tube clamped between the bottom wad and the metal base, and rolled from coils—layers of paper with thickness of 130 ÷ 170 mcm, and having temporary resistance δ (kgf/cm²) not less than 9 in machine direction and 5 in transverse direction and relative elongation ε (%) of not less than 3 in machine direction and 7 in transverse direction. Sleeve tube is made with the number of turns—layers N for each gauge by winding on the spindle of N pieces of full turns—layers of paper. Number N is calculated by derived mathematical formula Ni=(H−Bi)/2C, where Bi is the inner diameter of the barrel bore, H is the inner diameter of the chamber at the end of the cartridge chamber, C is the thickness of the paper, where i=1 for the lower—small values of the half-range of values of the inner diameter of the channel of the smooth-bore weapon of the central fire, and i=2 for upper—large values of half-range of values B2 of inner diameter of channel of smooth-bore weapon of central strike. Also disclosed is a multilayer paper assembly sleeve with a bottom wad height less than the height of the metal base.

EFFECT: enabling the possibility of creating a multilayer paper assembled cartridge case for cartridges of various calibers with an inner diameter as close as possible to the smooth-bore gun barrel inner diameter, for which it is intended and which has all full turns—layers of paper, to ensure high accuracy and sharpness of fire and to exclude the possibility of increasing pressure of powder gases in the chamber of the weapon during firing.

4 cl, 1 dwg, 3 tbl