Coated projectile body

Abstract

The present invention relates to a projectile for ammunition, in particular of a maximum caliber of 20 mm or 13 mm, comprising a metal projectile body and a surface coating that has a thickness of more than 100 µm and at least partially forms an outer skin of the projectile.

Description

[0001] Coated projectile body

[0002] The present invention relates to a projectile for ammunition, particularly for the military and / or government sector. For example, the caliber is less than 20 mm, in particular less than 13 mm. The present invention can relate to deformation projectiles, hollow-point projectiles, full metal jacket projectiles, and monolithic projectiles, for example for military and / or government ammunition. Military ammunition is characterized, among other things, by a firing range generally of up to 600 meters. Furthermore, generic military and / or government ammunition has a caliber-specific, defined trajectory and muzzle energy as well as a predetermined penetration capability, with no or clearly defined fragmentation of the projectiles after impact with the target. Furthermore, the invention can relate to projectiles for practice cartridges, particularly for use in low-pollution shooting ranges.In military training, ammunition consumption is increased, which is why low barrel loading and the associated long barrel life are desired. The present invention also relates to such ammunition and a method for producing projectiles according to the invention.

[0003] Lead has the advantage of having an excellent density for bullets. This minimizes the length of the projectile while maintaining its weight, which positively influences its external ballistics. Lead's ductility also ensures reliable pressing into the rifling profile of the firearm barrel, thus minimizing stress on the barrel. For environmental and health reasons, especially on practice shooting ranges, the use of lead as a material for bullets is becoming increasingly unsuitable or even prohibited. Thus, the choice of material for bullets presents a conflict of interest, particularly between good accuracy and range, environmental compatibility, and production costs.Alternative materials to lead, such as tin and zinc, have proven less suitable due to their low density. While this would ensure better environmental compatibility, it results in significant losses in terms of accuracy and range. Furthermore, alternative solutions such as solid steel or brass projectiles also have significant disadvantages with regard to barrel life and penetration resistance through the firearm barrel. This results in unfavorable internal ballistics. Such solid-body projectiles, especially steel projectiles, have two major disadvantages with regard to their surface area and barrel stress. Firstly, the base material is less ductile, resulting in increased barrel stress, and secondly, steel (barrel)-steel (projectile) combinations are unsuitable from a tribological perspective.

[0004] Particularly when using steel bullets, it has been found that undesirable interactions occur between the steel bullet and the barrel, which is usually also made of steel. It has been identified that when using steel bullets, the steel barrel expands by a few hundredths of a millimeter, which negatively impacts accuracy, rotational transmission, and gas leakage. Furthermore, unwanted abrasive wear and diffusion welding occur.

[0005] Thin-layer surface treatments for steel bullets are known, for example, from US Pat. No. 5,686,693. However, it has been found that surface wear and barrel expansion can only be marginally positively influenced. Furthermore, it has been demonstrated that the surface coatings do not readily adhere sufficiently to the bullet's body. This lack of adhesion, in turn, negatively impacts the transmission of torque via the rifling profile in the firearm barrel.

[0006] It is an object of the present invention to overcome the disadvantages of the prior art, in particular to provide a bullet with improved barrel expansion prevention and / or improved adhesion of a surface coating to the bullet body.

[0007] This object is achieved by the subject matter of the independent claims. According to this, a projectile for ammunition is provided, in particular with a caliber of at most 20 mm or at most 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, projectiles according to the invention are also used for ammunition with a caliber of less than 7 mm or at most 5.6 mm. The projectile can also be referred to as a solid projectile, since projectiles according to the invention, in contrast to jacketed projectiles, which generally consist of a projectile jacket made of deformable material, such as tombac, and a projectile body inserted therein, which is manufactured separately from the projectile jacket, do not have a separate jacket. In particular, the projectile is manufactured from a single piece.

[0008] The bullet has a metallic bullet body, also called a bullet core. The bullet body can, for example, comprise or consist 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 consist of 100% or percent by weight of iron, but can contain alloy components. The bullet body can, for example, have an iron content or percent by weight of iron of at least 20%, in particular at least 30%, 40%, 50%, 60%, 70%, 80%, and less than 100%. The percent by weight of iron is particularly preferably at least 90% or at least 95% and less than 100%. For example, the bullet body can be made of soft iron and / or have a carbon content of more than 0.05%. Furthermore, the carbon content can be up to 2%, in which case the iron material is referred to as steel.It has been discovered that increasing the carbon content increases the hardness and tensile strength of the bullet, which has a beneficial effect on its final ballistics. The bullet according to the invention is environmentally friendly and can exhibit improved ballistics. Furthermore, the high carbon content has a corrosion-protective effect on the bullet. Furthermore, the bullet body can comprise iron and additionally at least one further transition metal, for example selected from the group containing manganese and copper, in particular in a mass fraction of 0.01% to 1.2% or 0.3% to 1%. Furthermore, according to a further exemplary embodiment, the iron of the bullet body can comprise at least one additive selected from the carbon group, the nitrogen group, and / or the oxygen group. The at least one additive can be a semimetal, for example silicon.Furthermore, the at least one additive can have a weight percentage of 0.01% and / or at most 1%, in particular of at most 0.5% or of at most 0.48%. In a further exemplary embodiment, the iron of the projectile body has a copper content of less than 4.0%, in particular of less than 0.3% or less than 0.25%.

[0009] According to one aspect of the present invention, the bullet has a surface coating which forms an outer skin of the bullet at least in sections and has a thickness of more than 100 μm. The surface coating can have a lubricating and / or diffusion-inhibiting effect on the firearm barrel, such that the bullet acceleration in the barrel is increased and the barrel load is reduced because less penetration resistance can be generated. This leads to less abrasions in the barrel. Furthermore, the surface coating can have an anti-corrosive 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 bullet acceleration in the barrel, barrel load and / or rust protection. As a key figure for assessing sliding orFor smear layers, the surface-to-volume ratio between the surface of the projectile body to be coated and the volume of the surface coating can be used.

[0010] The thick surface coating provided according to the invention is capable of significantly reducing surface wear and barrel elongation. In particular, the surface coating is only applied to the projectile body once it has already achieved its final projectile shape, i.e., once it has been completely formed into the shape that will become the projectile. This, among other things, addresses the misconception that thick surface coatings do not adhere well to the base body. The present invention overcomes this misconception and achieves strong adhesion to the projectile body despite the thick surface coating, thus ensuring its functionality and allowing the spin from the rifling-field profile to be transferred to the projectile body.

[0011] In another exemplary embodiment of the projectile, the projectile body is completely coated with the surface coating. Alternatively or additionally, the surface coating can have a varying layer thickness. The layer thickness, particularly in the case of electrolytic coatings, can be thicker at corners, edges, transitions, or the like than at adjacent, particularly straight, such as cylindrical, and / or edge-free wall sections. The inventors of the present inventions have recognized that the accumulation of material of the coating at corners, edges, transitions, or the like can be used to further reduce wear.In particular, in edge-free sections of the projectile body, such as in the area of ​​the particularly cylindrical guide band, the projectile tail and / or in the area of ​​the particularly ogive-shaped projectile front, the layer thickness in the circumferential direction and / or in the longitudinal direction of the projectile can have a substantially constant layer thickness, wherein substantially constant is to be understood in the sense that a deviation in the thickness of the surface coating in the range of + / - 10 pm can occur.

[0012] In an exemplary embodiment of the bullet according to the invention, the surface coating contains or consists of a material selected from the list including copper, zinc, tin, nickel, chromium, and / or alloys thereof. It should be understood that the aforementioned components of the surface coating material extend beyond the mere presence of trace elements.

[0013] According to a further aspect of the present invention, which can be combined with the preceding aspects and exemplary embodiments, the invention is provided for ammunition, in particular with a caliber of at most 20 mm or at most 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 invention are also used for ammunition with a caliber of less than 7 mm or at most 5.6 mm. The bullet can also be referred to as a solid bullet, since, in contrast to jacketed bullets, which generally consist of a bullet jacket made of deformable material, such as tombac, and a projectile body inserted therein, which is manufactured separately from the bullet jacket, the bullet according to the invention does not have a separate jacket. In particular, the bullet is manufactured from a single piece.

[0014] The bullet has a metallic bullet body, also called a bullet core. The bullet body can, for example, comprise or consist 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 consist of 100% or percent by weight of iron, but can contain alloy components. The bullet body can, for example, have an iron content or percent by weight of iron of at least 20%, in particular at least 30%, 40%, 50%, 60%, 70%, 80%, and less than 100%. The percent by weight of iron is particularly preferably at least 90% or at least 95% and less than 100%. For example, the bullet body can be made of soft iron and / or have a carbon content of more than 0.05%. Furthermore, the carbon content can be up to 2%, in which case the iron material is referred to as steel.It has been discovered that increasing the carbon content increases the hardness and tensile strength of the bullet, which has a beneficial effect on its final ballistics. The bullet according to the invention is environmentally friendly and can exhibit improved ballistics. Furthermore, the high carbon content has a corrosion-protective effect on the bullet. Furthermore, the bullet body can comprise iron and additionally at least one further transition metal, for example selected from the group containing manganese and copper, in particular in a mass fraction of 0.01% to 1.2% or 0.3% to 1%. Furthermore, according to a further exemplary embodiment, the iron of the bullet body can comprise at least one additive selected from the carbon group, the nitrogen group, and / or the oxygen group. The at least one additive can be a semimetal, for example silicon.Furthermore, the at least one additive can have a weight percentage of 0.01% and / or at most 1%, in particular of at most 0.5% or of at most 0.48%. In a further exemplary embodiment, the iron of the projectile body has a copper content of less than 4.0%, in particular of less than 0.3% or less than 0.25%.

[0015] The projectile body has a tapered, particularly ogive-shaped, front end, a narrow, particularly cylindrical, guide band adjoining the front end for engaging the rifling profile of a firearm barrel, and a truncated cone-shaped rear end adjoining the guide band. For example, the front end, rear end, and guide band are made from a single piece, particularly from a metal body. In the case of a cylindrical guide band, this can also be referred to as a guide band collar. Its abrupt insertion into the firearm barrel prevents a wedge effect between the firearm barrel and the projectile and thus suppresses the expansion of the firearm barrel.

[0016] According to a further aspect of the invention, the projectile comprises a surface coating that at least partially covers the tail of the projectile, the coating having a thickness that at least partially increases from the guide strip towards the tail of the projectile. The varying surface coating thickness in the region of the tail of the projectile ensures that the projectile does not have its largest outer diameter towards the tail of the projectile, which is to be avoided for manufacturing reasons. The shape of the projectile according to the invention makes it possible to take into account the problem inherent in the prior art that, due to the process involved in many coating methods, the greatest layer thickness results precisely in the tail of the projectile. This phenomenon is compensated for in the projectile shape according to the invention, with the frustoconical outer contour of the projectile that tapers towards the tail of the projectile.It should be understood that the thickness of the surface coating may remain constant or even decrease in sections from the guide band to the tail of the bullet. For example, a type of reservoir and / or accumulation of surface coating may occur at the tail of the guide band, particularly at a contour jump present at the transition from the guide band to the adjoining tail of the bullet. This may locally, particularly immediately adjacent to the tail of a guide band, initially lead to a decreasing surface coating thickness in the section of the tail of the bullet immediately adjacent to the guide band. Furthermore, the manufacturing accuracy of the blank and the manufacturing technique for applying the surface coating influence the actual coating thickness. The fundamental trend towards increasing coating thickness is crucial for this aspect of the invention.In the area from the rear of the floor to the floor there may be a constant increase in the coating layer.

[0017] According to an exemplary development of the projectile according to the invention, an angle of inclination of the truncated cone-shaped projectile tail with respect to the longitudinal axis of the projectile is in the range of 0.5° to 5 0 The length of the truncated cone-shaped tail of the projectile, viewed in the longitudinal direction of the projectile, can range from 10% to 50% of the total projectile length.

[0018] According to a further aspect of the present invention, which can be combined with the preceding aspects and exemplary embodiments, a projectile for ammunition is provided, in particular with a caliber of at most 20 mm or at most 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, projectiles according to the invention are also used for ammunition with a caliber of less than 7 mm or at most 5.6 mm. The projectile can also be referred to as a solid projectile, since projectiles according to the invention, unlike jacketed projectiles, which generally consist of a projectile jacket made of deformable material, such as tombac, and a projectile body inserted therein, which is manufactured separately from the projectile jacket, do not have a separate jacket. In particular, the projectile is manufactured from a single piece.

[0019] The bullet has a metallic bullet body, also called a bullet core. The bullet body can, for example, comprise or consist 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 consist of 100% or percent by weight of iron, but can contain alloy components. The bullet body can, for example, have an iron content or percent by weight of iron of at least 20%, in particular at least 30%, 40%, 50%, 60%, 70%, 80%, and less than 100%. The percent by weight of iron is particularly preferably at least 90% or at least 95% and less than 100%. For example, the bullet body can be made of soft iron and / or have a carbon content of more than 0.05%. Furthermore, the carbon content can be up to 2%, in which case the iron material is referred to as steel.It has been discovered that increasing the carbon content increases the hardness and tensile strength of the bullet, which has a beneficial effect on its final ballistics. The bullet according to the invention is environmentally friendly and can exhibit improved ballistics. Furthermore, the high carbon content has a corrosion-protective effect on the bullet. Furthermore, the bullet body can comprise iron and additionally at least one further transition metal, for example selected from the group containing manganese and copper, in particular in a mass fraction of 0.01% to 1.2% or 0.3% to 1%. Furthermore, according to a further exemplary embodiment, the iron of the bullet body can comprise at least one additive selected from the carbon group, the nitrogen group, and / or the oxygen group. The at least one additive can be a semimetal, for example silicon.Furthermore, the at least one additive can have a weight percentage of 0.01% and / or at most 1%, in particular of at most 0.5% or of at most 0.48%. In a further exemplary embodiment, the iron of the projectile body has a copper content of less than 4.0%, in particular of less than 0.3% or less than 0.25%.

[0020] According to a further aspect of the invention, the bullet comprises a surface coating made of a mineral such as graphite and / or plastic, which forms the outer skin of the bullet at least in sections and has a thickness in the range of more than 50 μm and at most 500 μm. The minerals or plastics have the advantage that they have an inherent corrosion-protective effect and at the same time act as a lubricating or sliding layer with respect to the firearm barrel, thus resulting in an improvement in terms of bullet acceleration in the barrel or barrel load, as well as in terms of preventing rusting of the bullet. It is entirely possible that mixtures of the aforementioned materials are used for the surface coating, or that the surface coatings consist entirely of the individual materials.Corrosion protection is a key factor, particularly in the military and government sector, to ensure the longevity of ammunition, which is usually procured in large quantities. Ammunition is often stored under adverse conditions and within wide temperature ranges. An important quality criterion for qualifying military and government ammunition is the salt water spray test. The salt spray test is a standardized test for evaluating the corrosion protection effectiveness of coatings or coatings, for example, according to international standards ASTM B117 or DIN EN ISO 9227.

[0021] In an exemplary development of the projectile, the plastic is selected from a list containing a thermoplastic, in particular a high-temperature-resistant thermoplastic, such as PEEK, a high-molecular-weight thermoplastic, such as POM, or a thermoplastic of the polyolefin class, such as PE, a polymer containing both amide and imide groups, such as PAI, a polymer of the polyhalogen olefin class, such as PTFE, and / or a synthetic polymer, such as silicone.

[0022] In an exemplary embodiment, the plastic surface coating can be applied by a dipping process.

[0023] In general, electroplating processes are suitable for surface coatings. According to an exemplary embodiment of projectiles according to the invention, the surface coating has or consists of a particularly CR(VI)-free electroplating layer, in particular made of metal from the group comprising 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 "Use elements - Electroplated coating systems." Furthermore, the surface coating can also be applied by a process using cathode sputtering, in particular sputtering. Furthermore, it is possible to realize tribologically optimized surface coatings using polymer-chemical molecules.For example, the surface coating can be produced as a galvanic coating, particularly to increase corrosion resistance, for example in accordance with the standard DIN 50961: 2012-04 “galvanic coatings - zinc coatings on ferrous materials” or DIN 50970: 2008-07 “metallic coatings - galvanic zinc and zinc alloy coatings on ferrous materials and additional CR(VI)-free treatments”.

[0024] In an exemplary further embodiment of the present invention, the projectile body has a tapered, in particular ogive-shaped, projectile front and a narrow, in particular cylindrical, guide band adjoining the projectile front for engaging the rifling-field profile of a firearm barrel. In the case of a cylindrical guide band, this can also be referred to as a guide band collar. Its abrupt pressing into the firearm barrel prevents a wedge effect between the firearm barrel and the projectile and thus suppresses the expansion of the firearm barrel. At the transition from the guide band to the projectile front, a shoulder is formed, in particular circumferential, preferably sharp-edged and / or shaped as a contour jump, which together with the outer surface of the projectile front forms a reservoir for the surface coating. The shoulder at the transition from the guide band to the projectile front can also be referred to as a tear-off edge.For example, the separation edge or shoulder is oriented at a right angle to the longitudinal axis of the bullet. The reservoir for the surface coating allows for local accumulation of the surface coating oriented toward the bullet front. The increased coating thickness is particularly helpful in ensuring a cushioned glide of the bullet body, especially its guide band, into the rifling profile of the firearm barrel. Furthermore, the guide band sleeve increases the torsional strength of the coating, preventing shearing of the coating during the transfer of spin in the firearm barrel during firing.

[0025] According to a further exemplary embodiment of the present invention, the coating thickness in the reservoir is more than 125%, in particular more than 150%, in particular more than 200%, in particular more than 250%, in particular more than 300% or more than 350%, of an average coating thickness of the

[0026] Surface coating. The average coating thickness can be understood, in particular, as the coating thickness of the surface coating averaged with respect to the longitudinal axis of the projectile. Crucial to this aspect of the invention is that there is a significant accumulation in the reservoir area compared to the remaining surface coating in the remaining part of the projectile.

[0027] According to a further exemplary embodiment of the present invention, the projectile body has an elongated, truncated cone-shaped tail, which merges into a projectile base by means of a tail cone whose inclination relative to the longitudinal axis of the projectile is greater than the inclination of the tail. For example, the inclination of the tail cone relative to the longitudinal axis of the projectile is in the range of 15 0 to 45 °, especially in the range of 20 0 to 40 °, especially in the range of 25 0 up to 35 0 or about 30 °.

[0028] According to another exemplary embodiment, the surface coating has a hardness in the range of 20 HV to 150 HV, in particular a hardness in the range of 30 HV to 125 HV or a hardness in the range of 40 HV to 100 HV. It has been found that, on the one hand, for effective lubrication and sliding during operation, and on the other hand, to ensure sufficient stability, a certain surface coating hardness is necessary to meet this conflicting objective.

[0029] According to a further exemplary embodiment, the plastic surface coating has a hardness in the range of 70 Shore A to 100 Shore D, in particular a hardness in the range of 80 Shore A to 90 Shore D or a hardness in the range of 90 Shore A to 80 Shore D. It has been found that, on the one hand, for effective lubrication and sliding during operation and, on the other hand, to ensure sufficient stability, a certain surface coating hardness is necessary in order to fulfill the above-mentioned conflict of objectives when using plastic as a material for the surface coating.

[0030] According to a further aspect of the present embodiments, which can be combined with the preceding aspects and exemplary embodiments, ammunition is provided, in particular with a caliber of less than 20 mm or less than 13 mm. The ammunition comprises an ammunition case and a projectile arranged therein, in particular pressed into it, which is designed according to one of the previously described aspects or exemplary embodiments.

[0031] According to a further aspect of the present invention, which can be combined with the preceding aspects and exemplary embodiments, a method is provided for producing a projectile for ammunition, in particular according to the invention, in particular with a caliber of at most 20 mm or at most 13 mm.

[0032] In the manufacturing method according to the invention, a metallic blank, in particular made of iron, is formed into a projectile body with a tapered, in particular ogive-shaped, projectile front. The projectile body can be formed from a one-piece iron blank (chemical element symbol 'Fe') or an iron alloy blank. It should be understood that the projectile core or projectile body does not have to consist of 100% or 100% by weight iron, but can contain alloying components. The projectile body can, for example, have an iron content or weight percentage of iron of at least 20%, in particular at least 30%, 40%, 50%, 60%, 70%, 80%, and less than 100%. Particularly preferably, the iron weight percentage is at least 90% or at least 95% and less than 100%. For example, the blank or projectile body may be made of soft iron and / or have a carbon content of more than 0.05%.Furthermore, the carbon content can be up to 2%, in which case the iron material is referred to as steel. The formed projectile body can further comprise a narrow, in particular cylindrical, guide band adjoining the projectile front for engaging the rifling-field profile of a firearm barrel, and a frustoconical projectile tail adjoining the guide band. Furthermore, the projectile body can comprise iron and additionally at least one further transition metal, for example selected from the group containing manganese and copper, in particular in a mass fraction of 0.01% to 1.2% or 0.3% to 1%. Furthermore, according to a further exemplary embodiment, the iron of the projectile body can comprise at least one additive selected from the carbon group, the nitrogen group, and / or the oxygen group. The at least one additive can be a semimetal, for example silicon.Furthermore, the at least one additive can have a weight percentage of 0.01% and / or at most 1%, in particular of at most 0.5% or of at most 0.48%. In a further exemplary embodiment, the iron of the projectile body has a copper content of less than 4.0%, in particular of less than 0.3% or less than 0.25%.

[0033] Furthermore, in the method according to the invention for forming an outer skin of the projectile, a surface coating is applied at least in sections to the formed projectile body.

[0034] In an exemplary embodiment of the method according to the invention, the surface coating is applied galvanically, in particular in a galvanic immersion bath, or produced by sputtering.

[0035] Preferred embodiments are specified in the subclaims.

[0036] In the following, further properties, features and advantages of the invention will become clear by describing preferred embodiments of the invention with reference to the accompanying exemplary drawings, in which:

[0037] 64 / 844.0 Figure 1 is a side view of an exemplary embodiment of a projectile according to the invention; and

[0038] Figure 2 shows a detailed view according to section II in Figure 1.

[0039] In the following description of exemplary embodiments of the invention, a projectile according to the invention is generally provided with the reference number 1, which is to be understood as a solid projectile, the projectile body of which, which is generally identified by the reference number 3, is made from one piece, in particular from iron, such as soft iron, preferably by forming.

[0040] Figure 1 shows an exemplary embodiment of the projectile 1 according to the invention in a side view. A flight direction F is schematically indicated by an arrow F and points to the left in Figure 1. In relation to the projectile flight direction F, the terms bow or front, bow side or front side, and rear, rear side or rear side, are to be understood. Basically, projectiles 1 according to the invention can be divided into three main sections: a projectile front 5; an adjoining guide band 7; and a projectile rear 9 adjoining the guide band 7. The projectile front 5 has a substantially ogive-like shape and tapers in the flight direction F, which is oriented parallel to the projectile longitudinal axis L in Figure 1, forming an ogive outwards towards a flat frontal face pointing in the flight direction F, which forms a projectile nose 11.

[0041] The ogive-shaped projectile front ends at the rear in the guide band 7. In the direction of the guide band 7, the curvature of the ogive 5 decreases continuously, so that immediately before a transition 13 into the guide band 7, the projectile front approaches at least a cylindrical shape. The guide band 7 generally serves to guide the projectile within a firearm barrel and / or to engage with a rifling-field profile of the firearm barrel. In the projectiles 1 according to the invention, the guide band 7 defines a maximum outer diameter of the projectile 1. This is achieved, among other things, in that the transition 13 from the guide band 7 into the projectile front 5 is formed by a shoulder in the form of an outer contour recess, at which an outer diameter of the projectile 1 decreases abruptly. The circumferential outer contour recess is particularly visible in Figure 2 and is identified by the reference numeral 15.The outer contour recess serves several functions. Firstly, it can ensure that essentially only the guide band 7 engages the rifling-field profile of the firearm barrel. By minimizing the engagement and / or sliding contact between the bullet and the firearm barrel to essentially a preferably narrow-band, cylindrical guide band 7, the penetration resistance of the bullet 1 within the firearm barrel can be reduced. Furthermore, the outer contour recess 15 forms a reservoir 17 in which a surface coating, generally designated by the reference numeral 19, can accumulate. In this regard, reference is made to the explanations regarding Figure 2 below.

[0042] Furthermore, as shown in Figures 1 and 2, the guide strip 7 also extends radially from the rear end of the projectile tail 9. A transition 17 from the projectile tail 9 into the guide strip 7 is formed by an outer contour projection, in which an outer diameter of the projectile 1 continuously increases. The outer contour projections in the region of the transitions 13, 21 can have an angle of inclination with respect to the longitudinal axis L of the projectile 1 in the range of 10 0 up to 90 0wherein, according to the preferred embodiment in Figures 1 and 2, the angle in the region of the transition 13 is 90° and the angle designated by the reference symbol ß is approximately 40° in the region of the rear transition 21. A radial depth of the outer contour projections or recesses measured transversely to the longitudinal axis L of the projectile can be less than 0.5 mm, in particular approximately 0.2 mm. In addition to the technical effect of reducing the resistance to penetration by the firearm barrel, the rear outer contour projection 21 from the projectile 9 into the guide band 7 has the technical effect of what is known as breathing of the firearm barrel. This is achieved in that when a firearm is fired, the gas pressure that develops or builds up generates an elastic widening of the firearm barrel, which results in the projectile 1 sliding more gently within the firearm barrel.This means that the penetration resistance is increasingly reduced. It was discovered that the resulting gases are forced into the annular space defined between the rear outer contour projection in the area of ​​the transition 21 and the firearm barrel, thus elastically expanding the barrel radially, resulting in less abrasion between the firearm barrel and the projectile 1. The projectile tail 9 is truncated conically shaped, so that the outer surface of the projectile tail 9 tapers continuously from the guide band toward the projectile base 23, with an angle of inclination of the outer surface of the projectile tail 9 relative to the projectile's longitudinal axis L in the range of approximately 0.5. 0 up to about 5 0 At the rear, the projectile tail ends in a short tail cone 25, the inclination a of which with respect to the projectile's longitudinal axis L is in the range of 15 0 to 45 °, especially at 30 °.

[0043] The projectiles 1 according to the invention comprise a surface coating 19, which forms at least in sections an outer skin of the projectile 1 and is schematically indicated in Figure 2. The surface coating 19 can be designed according to one of the exemplary embodiments described above.

[0044] The projectile body 3 can be completely coated with the surface coating 19. Alternatively or additionally, the surface coating 19 can have a varying layer thickness along the longitudinal axis L of the projectile. Furthermore, the layer thickness, particularly in the case of electrolytic coatings, can be thicker at corners, edges and transitions or the like than at adjacent, in particular straight, such as cylindrical, and / or edge-free wall sections of the projectile body 3. The detailed section II shown in Figure 2 shows an enlarged view of the layer thickness profile of the surface coating 19 in the area of ​​the guide band 7. While the surface contour of the projectile body 3 has abrupt contour jumps, particularly in the area of ​​the shoulder 15 forming the reservoir 17 at the transition 13, the surface coating 19 is applied quite evenly, iewith an essentially continuous transition from the radially deeper projectile front 5 to the radially projecting guide band 7, onto the projectile body 3. This leads to the surface coating 19 accumulating in the reservoir 17, resulting in an increased layer thickness there. As can be seen in Fig. 2, the surface coating thickness increases continuously from the projectile front 5 to a maximum in the region of the reservoir 17 and from there continuously decreases again towards the guide band 7, from where on the layer thickness remains essentially constant. LIST OF REFERENCE SYMBOLS i Projectile.

[0045] 3 projectile bodies

[0046] 5 storey front

[0047] 7 Guide band

[0048] 9-story rear

[0049] 11 Nosepiece

[0050] 13, 21 Transition

[0051] 15 Paragraph or outer contour origin

[0052] 17 Reservoir

[0053] 19 Surface coating

[0054] 23 floor

[0055] 25 Tail cone a Angle of the tail cone ß Angle of the rear transition

[0056] F Flight direction

[0057] L Longitudinal axis of the projectile

Claims

SwissP Defence AG R31O78WO REQUIREMENTS 1. Projectile for ammunition, in particular with a caliber of not more than 20 mm or not more than 13 mm, comprising a metallic projectile body and a surface coating forming at least a portion of the outer skin of the projectile with a thickness of more than 10 ...

2. Floor according to claim 1, wherein the surface coating contains or consists of a material selected from the list containing copper, zinc, tin, nickel, chromium and / or alloys thereof.

3. Projectile, in particular according to claim 1 or 2, for ammunition, in particular with a caliber of at most 20 mm or at most 13 mm, comprising a metallic projectile body with a tapered, in particular ogive-shaped, projectile front, a narrow, in particular cylindrical, guide band adjoining the projectile front for engaging in the rifling profile of a firearm barrel and a frustoconical projectile tail closing onto the guide band and a surface coating covering at least the rear of the projectile at least in sections, with a thickness increasing at least in sections from the guide band towards the rear.

4. Projectile according to claim 3, wherein the guide band defines a maximum outer diameter of the projectile and is cylindrical and / or is angled with respect to the longitudinal axis of the projectile at an angle of 15° 0 transitions into the rear of the projectile at an angle of up to 70°.

5. Projectile according to claim 3 or 4, wherein the angle of inclination of the frustoconical rear of the projectile with respect to the longitudinal axis of the projectile is in the range of 0.5° to 5°. 0 lies.

6. Projectile, in particular according to one of the preceding claims, for ammunition, in particular with a caliber of at most 20 mm or of at most 13 mm, comprising a metallic projectile body and a surface coating made of plastic, forming at least a portion of the outer skin of the projectile, with a thickness in the range of more than 50 pm and at most 500 pm. - Projectile according to claim 6, wherein the plastic is selected from a list including a thermoplastic, in particular a high-temperature resistant thermoplastic such as PEEK, a high-molecular-weight thermoplastic such as POM, or a thermoplastic of the polyolefin class such as PE, a polymer containing both amide and imide groups such as PAI, a polymer of the polyhalolefin class such as PTFE, and / or a synthetic polymer such as silicone. Projectile according to any one of claims 6 to 7, wherein the plastic surface coating is applied by an immersion process. Projectile according to any one of the preceding claims, wherein the surface coating is applied by an electroplating process.A projectile according to any of the preceding claims, wherein the projectile body has a tapered, in particular ogive-shaped, projectile front and a narrow, in particular cylindrical, guide band adjoining the projectile front for engaging the rifling profile of a firearm barrel, wherein a shoulder is formed at the transition from the guide band to the projectile front, which forms a reservoir for the surface coating.

1. A projectile according to claim 10, wherein the coating thickness in the reservoir is more than 125%, in particular more than 150%, in particular more than 200%, in particular more than 250%, in particular more than 300% or more than 350%, of the average coating thickness of the surface coating. 2.A projectile according to any one of the preceding claims, wherein the projectile body has an elongated, frustoconical tail section which transitions into a base by means of a tail cone whose inclination with respect to the longitudinal axis of the projectile is greater than the inclination of the tail section.

3. Ammunition, in particular with a caliber of less than 20 mm, and in particular with a caliber of less than 13 mm, comprising a cartridge case and a projectile arranged therein according to any one of the preceding claims.

4. A method for manufacturing a projectile designed according to any one of claims 1 to 12 for ammunition, in particular with a caliber of at most 20 mm or at most 13 mm, wherein a metallic blank is formed into a projectile body with a tapered, in particular ogive-shaped, front and onto which... The reshaped projectile body is at least partially coated with a surface coating forming the outer skin of the projectile, in particular by electroplating.

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