Patent Application
20240230295
The present disclosure relates to a projectile for ammunition, in particular for the military and/or governmental area. For example, the caliber is less than 13 mm. The present disclosure may also relate to deformation bullets and, in particular, hollow point bullets, for example, for police and/or authority ammunition with a caliber of less than or equal to 13 mm.
Police and/or authority ammunition is characterized, among other things, by the fact that the firing range is generally less than 150 m. Generic deformation bullets are characterized by a defined wound-ballistic behavior, namely a predetermined deformation, in particular mushrooming, after impact on the target. Furthermore, the disclosure may relate to bullets for practice cartridges, such as for use on shooting ranges. For use on police shooting ranges, bullets for practice cartridges have to comply with various requirements, for example according to the “Technical Guideline (TR) Cartridge 9 mm×19, pollutant reduced” (in particular: as of September 2009) or other, in particular country-specific, ballistic requirements, with the proviso that for practice cartridges some requirements made in the said technical guideline for operational cartridges, inter alia with regard to the end ballistic effect, need not be met. Furthermore, the present disclosure relates to such ammunition.
Pure lead has the advantage that it has excellent dry lubrication properties even as a solid material. This minimizes friction in the barrel and realizes a high projectile velocity. The ductility of lead also ensures reliable pressing into the land-and-groove profile in the firearm barrel, so that the firearm barrel is subjected to minimal stress. For environmental and health reasons, in particular at practice shooting ranges, the use of lead as a material for bullets is increasingly unsuitable. In the choice of material for bullets, there is therefore a conflict of interest, in particular between good precision as well as flight range and environmental compatibility. Alternative materials to lead, such as tin, zinc and copper, have proved to be less suitable because of their low density, which would ensure better environmental compatibility, but would entail significant losses in terms of precision and flight range. Furthermore, alternative solutions as steel or brass solid projectiles also have decisive disadvantages in terms of barrel life and press-through resistance by the gun barrel. This results in unfavorable internal ballistics. Such solid-body projectiles, in particular steel projectiles, have two massive disadvantages in terms of surface and barrel loading. On the one hand, the base material is less ductile, resulting in increased barrel loading, and on the other hand, steel (barrel) and steel (projectile) combinations are unsuitable from a tribological point of view.
Such a solid bullet from soft iron is known from US4,109,581A. The solid bullet has an ogive-like bullet front, an adjoining slightly conical guide band, which makes up about ⅓ to ¼ of the bullet length, and a conical bullet tail. The bullet according to U.S. Pat. No. 4,109,581 has proven to have disadvantageous ballistics, in particular precision and flight range. Furthermore, the elongated guide band also has a disadvantageous effect on the internal ballistics of the bullet. The long guide band and the low ductility of iron cause a high barrel load, which also results in abrasion.
The accompanying drawings, which are incorporated herein and form a part of the specification, illustrate the embodiments of the present disclosure and, together with the description, further serve to explain the principles of the embodiments and to enable a person skilled in the pertinent art to make and use the embodiments.
The exemplary embodiments of the present disclosure will be described with reference to the accompanying drawings. Elements, features and components that are identical, functionally identical and have the same effect are—insofar as is not stated otherwise—respectively provided with the same reference character.
In the following description, numerous specific details are set forth in order to provide a thorough understanding of the embodiments of the present disclosure. However, it will be apparent to those skilled in the art that the embodiments, including structures, systems, and methods, may be practiced without these specific details. The description and representation herein are the common means used by those experienced or skilled in the art to most effectively convey the substance of their work to others skilled in the art. In other instances, well-known methods, procedures, and components have not been described in detail to avoid unnecessarily obscuring embodiments of the disclosure.
An object of the present disclosure is to address the disadvantages of the related art, including to provide a bullet which is compatible with the environment and health and has an increased barrel acceleration and/or a lower barrel load.
In an exemplary embodiment, a bullet is provided for the ammunition, in particular with a caliber of at most 13 mm of a handgun, in particular with a caliber of less than 13 mm. The caliber is generally referred to as a measure of the outer diameter of projectiles or bullets and the inner diameter of a firearm barrel. For example, bullets according to the disclosure are also used for ammunition with a caliber of less than 7 mm or at most 5.6 mm. The bullet may also be referred to as a solid bullet, since bullets according to the disclosure do not have a separate jacket, unlike jacketed bullets, which generally consist of a bullet jacket made of deformable material, such as tombac, and a bullet body inserted therein, which is manufactured separately from the bullet jacket. In particular, the bullet is made in one piece.
The bullet has a bullet body, also called bullet core, made of iron (chemical element symbol ‘Fe’) or an iron alloy. It should be understood that the bullet core or bullet body does not have to be 100% or percent by weight iron, but may contain alloy components. For example, the bullet body may have an iron content or weight percent of iron of at least 20%, particularly at least 30%, 40%, 50%, 60%, 70%, 80%, and less than 100%. In an exemplary embodiment, the iron weight percent content is at least 90% or at least 95% and less than 100%. For example, the bullet body may be made of soft iron and/or have a carbon content greater than 0.05%. Further, the carbon content may be up to 2%, in which case the iron material is referred to as steel. It has been found that increasing the carbon content increases the hardness and tensile strength of the bullet, which has a beneficial effect on the end ballistics. The bullet according to the disclosure is environmentally friendly and can have improved ballistics. Furthermore, the high carbon content has a corrosion-protective effect on the bullet.
According to one aspect of the present disclosure, the bullet body is at least partially provided with a surface coating forming an outer skin of the bullet having a thickness of at least 1 μm and at most 50 μm. The surface coating may have a lubricating effect with respect to the firearm barrel, such that the barrel acceleration is increased and the barrel load is decreased, since a lower press-through resistance can be generated. This leads to less abrasion in the barrel. Furthermore, the surface coating can have an anticorrosive effect. The selected thickness of the surface coating has proven to be optimal with regard to the properties of the bullets to be improved, namely barrel acceleration, barrel load and/or corrosion protection. The surface-to-volume ratio between the surface of the bullet body to be coated and the volume of the surface coating can be used as a key figure for evaluating sliding or lubricating layers. In the case of the bullets according to the disclosure, in particular those with a caliber of up to 13 mm, the surface-to-volume ratio has proved to be particularly advantageous for thicknesses between 1 μm and 50 μm.
According to an exemplary embodiment of the bullet according to the disclosure, the surface coating has a thickness of at least 3 μm, in particular at least 5 μm, and/or of not more than 30 μm, in particular not more than 20 μm, preferably not more than 10 μm. For example, the surface coating thickness is 7.5 μm+/−1 μm.
In another exemplary embodiment of the bullet, the bullet body is completely coated with the surface coating. This can be achieved particularly effectively, for example, by immersing the bullet body in an immersion bath to apply the coating. Alternatively or additionally, the surface coating can have a varying layer thickness. The coating thickness, particularly in the case of electrolytic coatings, may be pronounced thicker at corners, edges and transitions or the like than at adjacent, in particular rectilinear, such as cylindrical, and/or edge-free wall portions. The inventors of the present disclosures have recognized that material accumulation of the coating at corners, edges and transitions or the like can be used to further reduce wear. In particular, at edge-free sections of the bullet body, such as in the region of the in particular cylindrical guide band, the bullet tail and/or in the region of the in particular ogive-shaped bullet front, the coating thickness may exhibit a substantially constant coating thickness in the circumferential direction and/or in the longitudinal direction of the bullet, wherein substantially constant is to be understood in the sense that a deviation of the thickness of the surface coating in the range of +/−1 μm may be present.
According to an exemplary further development of bullets according to the disclosure, the surface coating has or consists of a in particular CR(VI)-free galvanic layer, in particular of metal from the group comprising or consisting of tin, zinc, nickel, cadmium, cobalt and alloys thereof. For example, the surface coating can be produced and/or applied in accordance with the standard DIN EN ISO 042: 2018-11 “Fasteners-galvanically applied coating systems”. Furthermore, the surface coating can also be applied by a process using cathode sputtering, in particular sputtering. Furthermore, there is the possibility to realize tribologically optimized surface coatings by means of polymer-chemical molecules.
For example, the surface coating can be produced as a galvanic coating, in particular to increase corrosion resistance, for example in accordance with the standard DIN 50961: 2012-04 “Galvanic coatings—Zinc coatings on iron or steel” or DIN 50970: 2008-07 “Metallic coatings—Galvanic zinc and zinc alloy coatings on iron or steel with supplementary CR(VI)-free treatment”.
According to another exemplary embodiment, the surface coating has a hardness in the range from 20 HV to 150 HV, in particular a hardness in the range from 30 HV to 125 HV or a hardness in the range from 40 HV to 100 HV. It has been found that, on the one hand, for effective lubrication and sliding in the barrel and, on the other hand, to ensure sufficient stability, a certain surface coating hardness is necessary to fulfill this conflict of objectives.
For example, the surface coating may comprise at least one zinc alloy with at least one alloy component from the group comprising iron and nickel. Such zinc coatings have proven to be particularly effective in terms of corrosion protection and, on the other hand, in terms of good sliding properties between the iron bullet body and the Hall gun barrel.
In another exemplary embodiment, the surface coating and/or bullet body is free of lead, copper and/or chromium. In order to be able to comply with the requirement for environmentally compatible bullets, the above-mentioned materials lead, copper and chromium are preferably dispensed with. However, it cannot be ruled out that trace elements or components of lead, copper and/or chromium may be present in lowest quantities in the surface coating and/or the bullet body.
Furthermore, the bullet body may comprise iron and additionally at least one further transition metal, for example selected from the group comprising manganese and copper, in particular to a mass proportion of 0.01% to 1.2% or of 0.3% to 1%.
Further, according to another exemplary embodiment, the iron of the bullet body may comprise at least one additive selected from the carbon group, the nitrogen group, and/or the oxygen group. The at least one additive may be a semimetal, for example silicon. Furthermore, the at least one additive may have a weight percentage of 0.01% and/or of at most 1%, in particular of at most 0.5% or of at most 0.48%.
In another exemplary embodiment, the iron of the bullet body has a copper content of less than 4.0%, particularly less than 0.3% or less than 0.25%.
According to an exemplary further development of the bullets according to the disclosure, the surface coating comprises or consists of a mineral such as graphite, and/or plastic, in particular a polymer such as PA, PAI or PTFE. The minerals and/or the plastics have the advantage that they have a material-specific corrosion-protective effect and at the same time act as a lubricating or sliding layer with respect to the firearm barrel, so that they have an improvement both with respect to barrel acceleration or barrel load and with respect to preventing corrosion of the bullet. It is quite possible that mixtures of the materials mentioned are used for the surface coating or that the surface coatings consist entirely of the individual materials.
In particular in the military-authority area, corrosion protection is an important factor in ensuring the longevity of ammunition, which is usually procured in large quantities. The storage of ammunition often takes place under adverse conditions and within large temperature ranges or margins. An important quality criterion for qualifying military and authority ammunition is the so-called saltwater spray test. The salt spray test is a standardized test for evaluating the corrosion protection effect of coatings or overlays. For example, according to the international standards ASTM B117 or DIN EN ISO 9227.
For example, the surface coating may be an iridescent coating, in particular a yellow iridescent coating. Furthermore, the surface coating may have a density in the range of 5 g/m3 to 10 g/m3, in particular in the range of 6 g/m3 to 8 g/m3.
For example, the surface coating has at least two layers of a base layer near the bullet body surface and an outer layer. Such a sandwich surface coating has the advantage that different desired properties can be applied to the bullet body via the two layers. The base layer can have a stronger adhesion effect with iron than the outer layer. Further, the outer layer may be more anti-corrosive and/or more lubricious than the base layer, in particular with respect to the material of the firearm barrel. According to an exemplary further development, the base layer comprises or consists of copper and the outer layer comprises or consists of tin or zinc.
In another exemplary embodiment, the surface coating has a sealant on the outer side, in particular facing away from the bullet body. The sealant, also called sealer, generally serves to prolong the anti-corrosion and/or sliding effect of the surface coating. The sealant is selected or adapted to bond to and react with the surface coating such that the anti-corrosion prolonging and sliding layer prolonging effect is achieved. For example, the sealant is organic, in particular comprising an oil, such as a vegetable oil. Furthermore, it is possible that the sealant is inorganic, for example a silicon-based sealant dissolved in water. The density of the inorganic sealant may be, for example, in the range of 1 g/m3 to 2 g/m3, in particular up to 1.5 g/m3 or 1.2 g/m3. The PH value may be, for example, in the range of 8-14, in particular in the range of 10-12.
Furthermore, the surface coating, in particular the base layer and/or the outer layer, can be made of a material whose melting point is greater than 250° C. The surface coating can also be made of a material whose melting point is greater than 250° C. Due to the fact that very high temperatures are reached in the firearm barrel, a low temperature sensitivity of at least the outer layer of the surface coating has proven to be advantageous, so that spalling or abrasion of the surface coating as a result of high temperatures cannot occur, which in turn could lead to the barrel being smoothly polished by erosion or to undesirable barrel deposits being produced.
According to another aspect of the present disclosure, combinable with the preceding aspects and exemplary embodiments, there is provided a bullet for ammunition, in particular with a caliber of less than 13 mm, for example of a handgun. The bullet may be formed according to any of the previously described aspects or according to any of the previously described exemplary embodiments.
The bullet comprises an in particular ogive-like bullet front, an in particular cylindrical guide band adjoining it in the longitudinal direction of the bullet for engaging in the land-and-groove profile of a barrel of the handgun. When in the present description of the disclosure reference is made to nose, front, nose-side or front-side, or rear, rear-side or rear-side, this is to be understood in this reference to a longitudinal axis of the bullet pointing in the direction of flight of the bullet. The guide band can be designed, for example, to engage in a land-and-groove profile of the firearm barrel, which serves in particular to set the bullet in a spin as it slides along inside the firearm barrel in order to stabilize the bullet trajectory.
According to a further aspect of the present disclosure, the bullet comprises a bullet tail adjoining the guide band in the longitudinal direction of the bullet, which defines the outer diameter or caliber of the bullet. The jacket surface of the bullet tail is structured at least sectionally, in particular sectionally when viewed in the longitudinal direction of the bullet, in such a way that the press-through resistance of the bullet tail with respect to the barrel is lower than that of the guide band and/or lower than without structuring in the bullet tail. The press-through resistance is a measure of the resistance experienced by the bullet, in particular due to friction with the firearm barrel during acceleration within the firearm barrel, which counteracts acceleration. The press-through resistance has an effect on the bullet abrasion, particularly in the case of monolithic bullets, as in the present case, on the barrel constriction and thus on the safety-relevant increase in gas pressure within the firearm barrel. According to the present disclosure, surface structuring can be understood as structuring of the jacket surface of the bullet tail, which leads to the press-through resistance of the bullet body in the region of the bullet tail being reduced compared to without surface structuring, which consequently reduces the press-through resistance of the entire bullet. This leads to increased barrel accelerations to be achieved and the barrel is less stressed, which in turn has less tendency to spalling on the outer surface of the bullet body and/or to barrel deposits. It should be made clear that surface structuring in the region of the bullet tail does not mean a mere reduction in diameter, for example via a shoulder or a conical transition, from the guide band into the bullet tail or as a chamfered bullet tail bottom, but in addition the jacket surface has a certain surface structuring or embossing.
According to an exemplary further development of the bullet according to the disclosure, the surface structuring is realized by pressing, in particular embossing, such as knurling or cording, or by introducing, in particular by machining or forming, a projection-recess-sequence. The projection-recess-sequence comprises at least two projections distributed in circumferential direction and at least two recesses distributed in circumferential direction therebetween. The longitudinal direction of the projections and recesses may be oriented in the longitudinal direction of the bullet. In particular, the surface structuring can be produced in a simple manufacturing manner via the pressure-forming production of the projection-recess-sequence. For example, the surface structuring is uniformly distributed in the circumferential direction and constant in the longitudinal direction of the bullet.
In an exemplary further development, the surface structuring comprises a circumferential projection-recess-sequence, in particular oriented in the longitudinal direction of the bullet, comprising in particular at least two projections and at least two recesses. The depressions may have a depth of at least 0.01 mm, in particular of at least 0.05 mm or at least 0.07 mm, and/or of at most 1 mm, in particular of at most 0.5 mm 0.4 mm or of at most 3-5 mm.
In another exemplary embodiment applicable to all aspects of the present disclosure, the bullet body has, at least sectionally, a structure that increases the adhesion base for the surface coating. For example, the surface-to-volume ratio for the surface coating is increased via the bullet body structure so that the barrel load can be further reduced. For example, the bullet body structure is realized by the above-mentioned surface structuring.
According to an exemplary further development, the bullet body structure is realized by the surface structuring in the form of a projection-recess-sequence, which can be formed according to the aspects described above or the exemplary embodiments, and the recesses are at least 50%, in particular at least 75% or completely, covered with the surface coating.
Accordingly, the recesses of the surface structuring can be understood as receiving pockets for the surface coating. For example, the recesses form lubricant or anti-corrosion agent receiving pockets. The increased absorption capacity for the surface coating can further improve the effects or advantages that can be achieved and are desired with the surface coating, such as reduced barrel load, increased barrel acceleration, reduced tendency for deposits or abrasion, and increased corrosion protection.
According to a further aspect of the present embodiments, which is combinable with the preceding aspect and exemplary embodiments, ammunition for firearms, in particular with a caliber of less than 13 mm, is provided. The ammunition comprises an ammunition case and a bullet, in particular a pressed-in bullet, which is formed according to one of the previously described aspects or exemplary embodiments, arranged therein.
According to a further aspect of the present disclosure, which can be combined with the preceding aspects and exemplary embodiments, there is provided a method for manufacturing a bullet, in particular according to the disclosure, for ammunition, in particular with a caliber of up to 13 mm.
In the manufacturing process according to the disclosure, a bullet body is formed from iron. The bullet body may be formed from a one-piece iron blank (chemical element symbol ‘Fe’) or an iron alloy blank. It should be understood that the bullet core or bullet body need not be 100% or percent by weight iron, but may contain alloy components. For example, the bullet body may have an iron content or percent by weight of iron of at least 20%, particularly at least 30%, 40%, 50%, 60%, 70%, 80%, and less than 100%. In an exemplary embodiment, the iron weight percent content is at least 90% or at least 95% and less than 100%. For example, the bullet body may be made of soft iron and/or have a carbon content greater than 0.05%. Further, the carbon content may be up to 2%, in which case the ferrous material is referred to as steel.
Furthermore, in the method of forming an outer skin of the bullet according to the disclosure, the bullet body is coated at least sectionally with a surface coating having a thickness of more than 1 μm and less than 50 μm.
In an exemplary embodiment of the method according to the disclosure, the surface coating is galvanically applied, in particular in a galvanic immersion bath, or is manufactured by sputtering.
In the following description of exemplary embodiments of the disclosure, bullets according to the disclosure are generally designated by the reference numeral 1. The bullets 1 of exemplary embodiments in the figures are all to be understood as solid bullets, the bullet bodies 2 of which, are made from one piece, in particular from iron, preferably by forming.
The ogive 9 leads into the guide band 5 at the rear-side. In the direction of the guide band 5, a curvature of the ogive 9 decreases continuously, so that immediately before a transition 13 into the guide band 5, the bullet nose 3 approaches at least a cylindrical shape. The guide band 5 generally serves to guide the solid bullet 1 within a firearm barrel and/or to engage a land-and-groove profile A, B of the firearm barrel. In the solid bullets 1 according to the disclosure, the guide band 5 defines a maximum outer diameter Da,max of the solid bullet 1. This is realized, among other things, by the fact that the transition 13 from the guide band 5 into the bullet nose 3 is formed by an outer contour recess at which an outer diameter Da of the solid bullet 1 is abruptly reduced. The circumferential outer contour recess is indicated schematically in
Furthermore, as shown in
The outer contour projections in the region of the transitions 13, 17 can have an angle of inclination with respect to a longitudinal axis of the bullet oriented in the longitudinal extension of the solid bullet 1 in the range of 10° to 90°, wherein according to
According to
In accordance with one aspect of the present disclosure, the bullet 1 is provided with a surface coating 29 having a thickness in the range of 1 μm to 50 μm, which forms the outer skin of the bullet 1. The surface coating 29 is schematically indicated by a dashed line on the outer skin of the bullet body 2. For example, according to
The bullet 1 illustrated in
According to the exemplary embodiments in
The bullet 1 according to the disclosure shown in
The features disclosed in the foregoing description, figures, and claims may be significant both individually and in any combination for the realization of the disclosure in the various embodiments.
| Number | Date | Country | Kind |
|---|---|---|---|
| 102021112014.4 | May 2021 | DE | national |
This patent application is a U.S. National Stage application of International Application No. PCT/EP2022/062059, filed May 4, 2022, which claims priority to German Patent Application No. 10 2021 112 014.4, filed May 7, 2021, each of which is incorporated herein by reference in its entirety.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2022/062059 | 5/4/2022 | WO |
