Thin walled steel cartridge case
AssigneeAmron Ltd.
InventorsRoy E. Rayle, Robert J. Brey, Wilbur John Woodruff
Life of this patent
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Abstract
A thin walled steel cartridge case having a substantially larger internal volume than a conventional cartridge case. The cartridge case is fabricated from a high strength, heat treated carbon steel or boron steel and the wall contour in the head area is designed to avoid localized high stress. A low friction coating is applied to the outer surface of the cartridge case and serves to reduce stress concentrations in the head area and to reduce extraction force in the event of interference between the case and the chamber during extraction.
Claims8
A thin walled steel cartridge case, comprising a head having a primer cavity, a hollow tapered thin wall section extending outwardly from the head and terminating in an open mouth, the inner surface of the head having an annular groove located concentrically of the primer cavity, and a generally curved outward diverging surface connecting the annular groove with the wall section, said case being formed of a steel having the following composition in weight percent:
- ______________________________________ Carbon 0.18 - 0.23 Manganese 0.80 - 1.10 Phosphorus 0.03 max. Sulfur 0.04 max. Silicon 0.10 max. Boron 0.0005 - 0.003 Iron balance. ______________________________________
A thin walled steel cartridge case, comprising an end head having an axial primer cavity, a hollow tapered wall section extending outwardly from the head and terminating in an open mouth of reduced diameter, the thickness of said wall section progressively decreasing in a direction from the head toward the mouth, the inner surface of said head having an annular groove located concentrically of the primer cavity, a generally curved surface connecting the outer periphery of the annular groove with said wall section at a juncture, said case being formed of steel having the following composition in weight percent:
- ______________________________________ Carbon 0.18 - 0.23 Manganese 0.80 - 1.10 Phosphorus 0.03 max. Sulfur 0.04 max. Silicon 0.10 max. Boron 0.0005 - 0.0030 Iron balance ______________________________________
- and a coating of a cured resin having a coefficient of friction less than 0.12 disposed on the outer surface of said wall section.
Dependencies are inferred from the claim text.