AU2022269277A1

AU2022269277A1 - Projectile for ammunition

Info

Publication number: AU2022269277A1
Application number: AU2022269277A
Authority: AU
Inventors: Markus Grünig; Donald Meyer; Michael MUSTER
Original assignee: RUAG Ammotec AG
Current assignee: RUAG Ammotec AG
Priority date: 2021-05-07
Filing date: 2022-05-04
Publication date: 2023-11-30
Also published as: IL308317A; CN117396719A; KR20240011151A; EP4334672A1; DE102021112014A1; WO2022233979A1; CA3216514A1

Abstract

The present invention relates to a projectile for ammunition, in particular of a caliber of not more than 13 mm, comprising an iron projectile core and a surface coating having a thickness of more than 1 µm and less than 50 µm that forms at least in part an outer skin of the projectile.

Description

RUAGAMMOTECAG,

Uttigenstrasse 67, 3602 Thun

Bullet for ammunition

The present invention relates to a bullet for ammunition, in particular for the military and/or governmental area. For example, the caliber is less than 13 mm. The present invention 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 invention may relate to bullets for practice cartridges, in particular for use on preferably police 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 x 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 invention 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 1/3 to 1/4 of the bullet length, and a conical bullet tail. The bullet according to US 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.

One object of the present invention is therefore to overcome the disadvantages of the prior art, in particular to provide a bullet which is compatible with the environment and health and has an increased barrel acceleration and/or a lower barrel load.

The object is solved by the subject-matter of the independent claims.

According to this, 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 invention 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 invention 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 1oo% 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%. Particularly preferably, the iron weight percent content is at least 90% or at least 95% and less than100%. 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 invention 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 invention, 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 Pm and at most 50 pm. 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 invention, 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 pm and 50 Pm.

According to an exemplary embodiment of the bullet according to the invention, the surface coating has a thickness of at least 3 pm, in particular at least 5 pm, and/or of not more than 30 pm, in particular not more than 20 pm, preferably not more than 10 Pm. For example, the surface coating thickness is 7,5 Pm +/- 1 Pm.

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 inventions 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 pm may be present.

According to an exemplary further development of bullets according to the invention, 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 of0,01% to 1,2% orof 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 o,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 invention, 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/m 3 to 10 g/m 3

, in particular in the range of 6 g/m 3 to 8 g/m 3 .

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/m 3 to 2 g/m 3 , in particular up to 1,5 g/m 3 or 1,2g/m 3 . 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 invention, 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 invention 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 invention, 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 invention, 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 invention, 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 invention, 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

%, 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 invention, 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 invention, for ammunition, in particular with a caliber of up to 13 mm.

In the manufacturing process according to the invention, 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 1oo% 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 %, 40%, 50%, 60%, 70%, 80%, and less than oo%. Particularly preferably, the iron weight percent content is at least 90% or at least 95% and less than oo%. 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 invention, the bullet body is coated at least sectionally with a surface coating having a thickness of more than 1 pm and less than 50 Pm.

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

Preferred embodiments are given in the subclaims.

In the following, further properties, features and advantages of the invention will become clear by means of a description of preferred embodiments of the invention with reference to the accompanying exemplary drawings, in which show:

Fig. 1 a side view of an exemplary embodiment of a bullet according to the invention;

Fig. 2 a sectional view of an exemplary embodiment of a further bullet according to the invention;

Fig. 3 a sectional view of a further exemplary embodiment of the bullet according to the invention;

Fig. 4 a rear view of an exemplary embodiment of a further bullet according to the invention;

Fig. 5 a side view of the bullet of Fig. 4; and

Fig. 6 a perspective view of the bullet from Figs. 4 and 5.

In the following description of exemplary embodiments of the invention, bullets according to the invention are generally designated by the reference numeral 1. The bullets 1 of the preferred embodiments in the figures are all to be understood as solid bullets, the bullet bodies of which, which are designated by the reference numeral 2, are made from one piece, in particular from iron, preferably by forming.

Fig. 1 shows an exemplary embodiment of the solid bullet 1 according to the invention in side view. A flight direction F is schematically indicated by an arrow and points to the right in Fig. 1. With respect to the bullet flight direction F, the terms nose, nose-side, front or front-side, and rear, rear-side or back-side are to be understood. Basically, solid bullets 1 according to the invention can be divided into three main sections: A bullet nose 3; a guide band 5 adjoining it; and a bullet tail 7 adjoining the guide band 5. The bullet nose has a substantially ogive-like shape and tapers in the direction of flight F, forming an ogive 9, towards a planar front face 11

pointing in the direction of flight F. Unlike standard known solid bullets, in which the ogive 9 terminates in a bullet tip realized by forming, for example, the planar front face 11 is formed by cutting the ogive 9 to length. It has been found that the ogive region flattened in this way and the resulting planar front face 11 have a positive effect on the external ballistics of the solid bullet 1 and that significantly lower forces are required in the manufacturing of the nose-side bullet ogive, which can be realized by forming, for example.

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 invention, 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 Fig. 1 by the visible edge marked by means of the reference sign 15. The outer contour recess 15 can ensure that substantially only the guide band 5 engages in the tension profile of the firearm barrel. This is illustrated further below with reference to Figs. 4 to 6. By minimizing the engagement and/or sliding contact between the solid bullet 1 and the firearm barrel to substantially a preferably narrow band guide band 5, the press-through resistance of the full bullet 1 within the firearm barrel 15 can be reduced.

Furthermore, as shown in Fig. 1, the guide band 5 is also radially offset at the rear-side from the bullet tail 7 adjoining it at the rear-side. A transition 17 from the bullet tail 7 into the guide band 5 is formed by an outer contour projection at which an outer diameter Da of the solid bullet 1 increases continuously. This is illustrated by the two visible edges 19, 21, which are spaced axially from one another in the longitudinal direction of the bullet and between which the outer contour of the solid bullet 1 widens continuously in the radial direction in the direction of the guide band 5.

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 100 to 900, wherein according to Fig. 1 the transition 17 lies in the range of 150 to 45, while at the transition 13 a 900 outer contour projection is formed from the bullet nose 3 into the guide band 5. Furthermore, a radial depth of the outer contour projection or outer contour recess to be measured transversely to the longitudinal axis of the bullet is less than 0,5 mm, in particular about 0,2 mm. In addition to the technical effect of reducing the press-through resistance by the firearm barrel, the rear side outer contour projection from the bullet tail 7 into the guide band 5 has the technical effect of so-called breathing of the firearm barrel. This is achieved by the fact that when a firearm is fired, the gas pressure that forms or builds up generates elastic widening of the firearm barrel, resulting in gentler sliding of the solid bullet 1 within the firearm barrel 15. This means that the press-through resistance is increasingly reduced. It has been found that the resulting gases press into the inter-tail-side outer contour projections in the region of transition 17 and the ring space delimiting the firearm barrel, thus elastically expanding the barrel radially, resulting in less abrasion between the firearm barrel and the solid bullet 1.

According to Fig. 1, the bullet tail has a cylindrical tail section 23 directly adjoining the guide band 5 or the transition 17. At the rear-side, the cylindrical tail section 23 is adjoined by abullet base 27 which opens into a bottom 25 and tapers concavely at least sectionally in the direction of the bottom 25. In this case, the radius of curvature of the concave section 27 of the bullet base is in the range of o,1 times to 0,5 times the maximum bullet outer diameter Da,max. The at least sectionally concave bullet base 27 also extends in the longitudinal direction of the full bullet 1 by 0,2 times to o,6 times the maximum bullet outer diameter Da,max . In addition, the bullet bottom 25 has an outer diameter Da which is in the range of o,6 times to o,9 times the maximum bullet outer diameter D .a

Furthermore, according to the solid bullet 1 in Fig. 1, it is provided that an axial length of the guide band 5 measured in the longitudinal direction of the solid bullet 1 is in the range of10 times to 100 times a groove-/land diameter difference of the firearm barrel 15. The difference between the internal diameter Di in the region of the groove diameter and the internal diameter Di in the region of the land diameter is to be understood as the groove-/land diameter difference.

In accordance with one aspect of the present invention, the bullet 1 is provided with a surface coating 29 having a thickness in the range of 1 Pm to 50 pm, 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 Fig. 1, the surface coating 29 is applied or present over the entire surface and in particular with a uniform layer thickness on the bullet body 2.

The bullet 1 illustrated in Fig. 2 is intended for use in practice cartridges, in particular for use on preferably police shooting ranges. In such practice cartridge bullets 1, the bullet body 2 has a bullet cavity 31 on the nose side, which is delimited circumferentially by a nose wall 33. The nose wall 33 is in particular ogive-shaped and opens into a bullet tip 35, which delimits a front side opening 37, which may also be substantially, in particular completely, closed. The nose wall 33 may taper substantially continuously toward the bullet tip 35. The bullet cavity 31 may, for example, have a planar cavity base 39, which may also be concave in shape, as viewed at least sectionally transversely along the longitudinal extension of the bullet 1. The concave or planar cavity base portion 39 leads into an outer cavity base portion 41 of greater curvature relative to the cavity base portion 39. The concavely curved outer cavity base portion 41 merges at a transition 43 into a cavity sidewall 45, which is oriented substantially at or at an acute angle relative to the longitudinal direction of the bullet.

According to the exemplary embodiments in Fig. 2, predetermined buckling points or notches 47 are introduced into the nose wall 33 at a distance from one another in the longitudinal direction of the bullet. At the predetermined buckling points 47, the wall thickness of the nose wall 33 is reduced abruptly. The predetermined buckling points 47 result in a predefined deformation in the target ballistics, namely a buckling in the nose wall 33 at the predetermined buckling points 47. The objective of the largest possible and fastest possible diameter increase ("flattening") can be achieved. A centering recess 51 may be introduced in the bullet base 49 of the bullet body 2, the cross-section of which is substantially triangular.

The bullet 1 according to the invention shown in Fig. 3 is, for example, a deformation bullet, in particular a hollow-point bullet, for example for police and/or authority ammunition. In order to avoid repetition with respect to the bullet 1 of Fig. 2, the differences in this respect will substantially be discussed. A significant difference between the hollow-point bullet 1 of Fig. 3 and the bullet 1 of Fig. 2 is that the nose wall 33 of the hollow-point bullet 1 of Fig. 3 is not compressed at the nose side, but extends substantially rectilinearly in the longitudinal direction of the bullet and thus delimits a sectionally cylindrical bullet cavity 31. The nose wall 33 has no predetermined buckling points 47.

Figs. 4 - 6 show a further exemplary embodiment of a bullet 1 according to the invention, which is similar in design to the bullet 1 of Fig. 1. In contrast to the embodiment according to Fig. 1,

the bullet 1 from Figs. 4 - 6 has a surface structuring on the rear side, which is generally indicated by the reference numeral 53. According to the exemplary embodiments, the surface structuring 53 comprises a sequence of projections 55 and recesses 57 distributed in the circumferential direction of the bullet, which projections 55 and recesses 57 are substantially equally distributed and equally formed in the circumferential direction, follow one another and extend in the longitudinal direction of the bullet with a substantially constant cross-section. Advantageously, the recesses 55 form receiving pockets for the surface coating so that the surface-to-volume ratio is improved. Viewed in the circumferential direction, the recesses 57 and the projections 55 may have substantially the same width dimension or may have different dimensions, wherein circumferential extensions may be in the range of 0,5 mm to 1,5 mm.

The features disclosed in the foregoing description, figures, and claims may be significant both individually and in any combination for the realization of the invention in the various embodiments.

Claims

1. Bullet (1) for ammunition, in particular with a caliber of at most 13 mm, comprising a bullet body (2) made of iron and a surface coating (29) forming an outer skin of the bullet at least sectionally and having a thickness of more than 1 pm and less than 50 pm.

2. Bullet (1) according to claim 1, wherein the surface coating (29) has a thickness of at least 3 pm, in particular at least 5 pm, and/or not more than 30 pm, in particular not more than 20pm, preferably not more than 10 pm, wherein in particular the surface coating (29) has a thickness of 7,5 Pm 1 pm.

3. Bullet (1) according to claim 1 or 2, wherein the bullet body (2) is completely coated with the surface coating (29) and/or wherein the surface coating (29) has a varying layer thickness.

4. Bullet (1) according to one of the preceding claims, wherein the surface coating (29) has or consists of an in particular Cr(VI)-free galvanic layer, in particular of metal of the group comprising or consisting of tin, zinc, nickel, cadmium, cobalt and alloys thereof.

5. Bullet (1) according to one of the preceding claims, wherein the surface coating (29) has a hardness in the range from 20 HV to 150 HV, in particular a hardness in the range from 40 HV to 100 HV.

6. Bullet (1) according to any one of the preceding claims, wherein the surface coating (29)

comprises at least one zinc alloy with at least one alloy component from the group comprising iron and nickel.

7. Bullet (1) according to any of the preceding claims, wherein the surface coating (29) and/or the bullet body (2) are/is free of lead, copper and/or chromium.

8. Bullet (1) according to one of the preceding claims, wherein the bullet body (2) comprises 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%.

9. Bullet (1) according to one of the preceding claims, wherein the iron of the bullet body comprises at least one additive selected from the carbon group, the nitrogen group and/or the oxygen group, wherein in particular the at least one additive is a semimetal, in particular silicon, and/or has a weight percentage of at least 0,01% and/or of at most 1%

or of at most o,5%.

10. Bullet (1) according to any one of the preceding claims, wherein the iron of the bullet body has a copper content of less than 0,4%, in particular less than 0,3% or less than0,25%.

11. Bullet (1) according to any of the preceding claims, wherein the surface coating (29)

comprises or consists of a mineral, such as graphite, and/or plastic, in particular a polymer, such as PA, PAI or PTFE.

12. Bullet (1) according to any one of the preceding claims, wherein the surface coating (29)

comprises at least two layers of a base layer near the bullet body surface and an outer layer, wherein the base layer has a stronger adhesion effect with steel than the outer layer and/or the outer layer being more anti-corrosive than the base layer, wherein in particular the base layer comprises or consists of copper and the outer layer comprises or consists of tin or zinc.

13. Bullet (1) according to any one of the preceding claims, wherein the surface coating (29) comprises a sealant on the outer side, wherein the sealant is organic, in particular comprises an oil, such as a vegetable oil, and/or is inorganic, for example a silicon-based sealant dissolved in water.

14. Bullet (1) according to any one of the preceding claims, wherein the surface coating (29), in particular the base layer and/or the outer layer, consists of a material whose melting point is greater than 250°C.

15. Bullet, in particular according to one of the preceding claims, for ammunition, in particular with a caliber of at most 13 mm, comprising an in particular ogive-like bullet front (3), an in particular cylindrical guide band (5) adjoining it in the longitudinal direction of the bullet for engaging in the land-and-groove profile of a barrel of the handgun, and a bullet tail (7) adjoining the guide band (5) in the longitudinal direction of the bullet, whose jacket surface is structured at least sectionally 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.

16. Bullet (1) according to claim 15, wherein the surface structuring (53) is realized by pressing in, in particular embossing, such as knurling or cording, or by introducing, in particular by machining or forming, a projection-recess-sequence (55, 57).

17. Bullet (1) according to claim 15 or 16, wherein the surface structuring (53) comprises a circumferential projection-recess-sequence (55, 57) in particular of at least two projections and recesses, wherein in particular the recesses have a depth of at least0,01 mm and/or of at most 1 mm.

18. Bullet (1) according to any of the preceding claims, wherein the bullet body (2) has, at least sectionally, a structure which increases the adhesion base for the surface coating (29).

19. Bullet (1) according to claim 18, wherein the bullet body structure is realized by the surface structuring (53) in the form of a projection-recess-sequence (55, 57) and the recesses are at least 50%, in particular at least 75% or completely, covered with the surface coating (29).

20. Ammunition, in particular with a caliber of less than 13mm, comprising an ammunition case and a bullet (1) according to any of the preceding claims arranged therein.

21. Method of manufacturing a bullet, in particular according to any one of claims 1 to 19, for ammunition in which a bullet body (2) is formed from iron and is coated at least sectionally with a surface coating (29) having a thickness of more than 1 Pm and less than 50 Pm for forming an outer skin of the bullet.

22. Method according to claim 21, wherein the surface coating (29) is galvanically applied, in particular is applied in a galvanic immersion bath, or is manufactured by sputtering.