PAPER SECTIONAL CASE FOR CARTRIDGES OF PLAIN-BARREL GUNS Russian patent published in 2003 - IPC

FIELD: hunting guns. SUBSTANCE: case comprises paper tube rolled from several layers of paper and fixed between bottom wad and metal bottom. Tube is rolled from paper having thickness between 100 and 160 μm and ultimate strength σ kgf/sq cm not less than: 9 in machine direction, 5 in transverse direction and elongation ε(%), % not less than: 3 in machine direction, 7 in transverse direction. Height of bottom wad is equal to height of metal base with accuracy of ± 0.5 mm or is smaller than height of metal base. Thickness h of wall of metal base is smaller than critical value h_cr chosen by empirical formula h_cr = (2σH)/σ_f, where σ_f is strength of metal fluidity of base; σ is ultimate strength in transverse direction, H is thickness of wall of paper tube. Electrical pressboard, GOST 2824-86, can be used as paper. Developed case is ecologically clean, has dynamic strength twice as high as paper case used at present and ensures reliable functioning of cartridges in various hunting guns, self- loading guns included. EFFECT: ensured reliable functioning of cartridges in various hunting guns. 4 cl, 2 dwg, 1 tbl