Steel ballistic shot and production method
AssigneeOlin Corporation
InventorsMorris C. Buenemann, Jr., Jack D. Dippold, Howard Muldrow, Peter W. Robinson, Brian Mravic
Life of this patent
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Abstract
A relatively high carbon, water-atomized, steel shot is softened via annealing to render it suitable for ballistic use. The annealing preferably includes decarburization from a surface layer or throughout and preferably provides the shot with a surface Knoop hardness of less than 250.
Claims20
A shotshell having a hull, a propellant charge in a powder chamber within the hull, a primer carried within a base of the hull, a plurality of shot pellets within a forward portion of the bull and wadding between the propellant charge and the plurality of shot pellets, characterized in that:
- the plurality of shot pellets are formed by water atomization of molten steel and a subsequent carbon removal process, on average leaving such pellets with a surface hardness of less than 250 KHN but at least 130 DPH at 21° C.
An ammunition shotload comprising plurality of iron-based shot pellets each comprising:
- a body consisting essentially of:
- a carbon content from 0% to 1.5% by weight;
- a silicon content from 0.1% to 2.0% by weight;
- a manganese content from 0.4% to 2.0% by weight;
- no more than about 3% additional material by weight;
- and
- balance iron, the body having a surface hardness of less than 250 KHN at 21° C.;
- and
- optionally a coating on the body.
A shotshell comprising:
- a hull having a base, a powder chamber and a forward portion;
- a propellant charge in the powder chamber within the hull;
- a primer carried within the base of the hull;
- a plurality of atomized iron-based shot pellets within the forward portion of the hull, the pellets having respective characteristic diameters (D) in inches and at least a surface layer of median Vickers hardness (H) of less than (300+((D−0.1)(−2000))) at 21° C.;
- and
- wadding between the propellant charge and the plurality of shot pellets.
An iron-based shot pellet comprising:
- an uncoated body consisting essentially of:
- a carbon content from 0.01% to 1.5% by weight;
- a silicon content from 0.1% to 2.0% by weight;
- a manganese content from 0.4% to 2.0% by weight;
- no more than about 1% additional material by weight;
- and
- balance iron, the body carbon-deleted surface layer having a Knoop hardness of less than 225 at 21° C. and a carbon-rich core portion having a Knoop hardness of more than 250 at 21° C.
A shotshell comprising:
- a hull having a base, a powder chamber and a forward portion;
- a propellant charge in the powder chamber within the hull;
- a primer carried within the base of the hull;
- a plurality of cast iron-based slot pellets within the forward portion of the hull, on average at least a surface layer of each such pellet having a median Vickers hardness of less than 200 if such pellet is #4 size or larger and a Vickers hardness of between 200 and 300 if such pellet is smaller than #4 size;
- and
- wadding between he propellant charge and the plurality of shot pellets.
Dependencies are inferred from the claim text.