EP2498045B1 - Projectile for practice ammunition - Google Patents

Description

The invention relates to a projectile for practice cartridges that should achieve a limited impact force when hitting particular on protective vests. In particular, the invention relates to a bullet or cartridge for self-loading.

An autoloader is a firearm that uses part of the energy released during the shot to re-arm the weapon. The self-unloader automatically opens the cap, i. without intervention of the shooter. This removes the empty cartridge case from the weapon, introduces a new cartridge to the weapon, tightens the ignition mechanism and closes the cap again.

Self-loading weapons can be designed so that the trigger must be operated again after each shot. In linguistic usage, the term semiautomatic has prevailed for this purpose. Self-loading weapons, which can fire bursts or continuous fire (the weapon shoots once the trigger is pulled once, until the trigger is released or the ammunition stock is exhausted) are called automatic or fully automatic.

In order to prevent a danger to the shooter, the closure may only be opened when the gas pressure in the barrel has fallen sharply. This is the case shortly after the bullet leaves the muzzle. On the other hand, sufficient energy must still be available to drive the mechanism. The shutter control depending on the ammunition used thus forms a central, constructive problem for the construction of self-loaders.

Armies and security services, such as the German Federal Armed Forces or police, often use cartridges with a caliber of 9mm for automatic weapons. Such a cartridge consists of the projectile, the sleeve, the propellant powder and the primer. The projectile is the object shot down by the weapon. The weight of the bullet one such 9mm caliber cartridge commonly used by armies is 8g. It flies at a speed of 340 to 350 m / s. It is a so-called supersonic projectile that generates a shockwave when leaving the muzzle, which is clearly audible as a projectile blast.

Practice cartridges are used, for example, by security agencies in many countries to reduce the risk of bullets and ricochets and not to injure a person wearing a vest. From the publication DE 10 2009 001 454 A1 Such a practice cartridge is known which has a cavity arranged in the outer region of the projectile. In case of multiple firing or bullet jackets of certain quality, the protective vest may puncture in individual cases. Experiments have shown that with a further reduction in the wall thickness of the ogive, it is no longer strong enough to ensure a safe supply of the cartridge. As an ogive referred to in longitudinal section similarly shaped profiles of tips ballistic long projectiles, which should have as low as possible air resistance in their locomotion. An ogive is a streamlined body of revolution that may be pointed or rounded at the front.

One approach to reducing punch through capability is to reduce the weight of a bullet. However, this leads to an increase in the velocity of the projectile. For example, a 9-gram bullet with a caliber of 9 mm achieves a muzzle velocity of approx. 420 m / sec,

Starting from a conventionally provided weight of a projectile such as 8 g with a cartridge caliber of 9 mm, an increase in weight is basically unproblematic. However, a reduction of the usual weight is usually problematic when the cartridge or the projectile is to be used in self-loaders, such as in an automatic weapon. Then threatens namely, that the shutter is not properly backwards is transported and an autoloader no longer works properly. This can be compensated for by an adapted internal ballistic, in which initially a higher internal pressure is generated by a more aggressive powder.

A bullet usually consists completely or at least predominantly of brass (that is, a mixture of copper and zinc) and usually of Tombak. Tombacs are called the brass varieties in which the proportion of copper is at least 80 wt .-%. The specific gravity of copper is 8.9 g / cc. The specific gravity of tin is 7.2 g / cc. The specific gravity of brass is at least 8.3 g / cc and the specific gravity of Tombak is 8.6 g / cc. The specified specific weights of brass or Tombak are desired in order to achieve a desired minimum weight of a bullet which is to be used in a self-loading.

However, the coat of a self-loading loft is not made of a firmer material such as Tombak, for reasons of weight alone. A firmer material such as Tombak is able to support the so-called Leistenkräfte, as in the DE 2031 7717 U1 is described. From this document is also known that a coat of a solid floor may consist of a soft iron. However, there is a risk of friction welding in low-carbon soft iron, which would worsen the bullet-run friction pairing to greater friction. At high bullet speed, the barrel can be destroyed by build-up welding until it is unusable.

The generic US Pat. No. 5,943,749 . DE-A-44 35 859 . US Pat. No. 5,259,320 . US-A 3,138,102 and WO 01/02795 all disclose a metallic projectile having a rear cylindrical portion and a forward arcuate ogive of the projectile, with a cavity enclosed by an ogive wall being disposed in the ogive. In this case, the projectile has a one-piece construction and in the cavity predetermined breaking points are provided.

The object of the present invention consists, starting from the US 5,943,749 to provide an improved bullet for practice cartridges of the type mentioned,

This object is achieved by a projectile with the features of claim 1. Advantageous embodiments emerge from the subclaims,

The metallic bullet for practice cartridges according to the invention initially comprises a rear cylindrical area, which is particularly solid (with the exception of the recess described below in the ground) and a front arcuate ogive of the projectile, wherein in the Ogive a cavity enclosed by an Ogivenwand is arranged. According to the invention, it is provided as a special feature that the front region of the ogive has a lower hardness than the rest of the projectile and / or the cavity has predetermined breaking points. With appropriate design of the ammunition, so the caliber, the propellant charge and the projectile, and taking into account the weapon used, can be achieved by both measures - individually or more frequently cumulatively - a safe operation of the weapon with reduced assets of the projectile to penetrate a protective vest. For ammunition 9 mm para was found that such a bullet can surprisingly well meet the high requirements of the standard "Technical Guideline (TR) cartridge 9 mm x 19, pollutant reduced", in particular as of: September 2009. This concerns police ammunition in caliber 9mm.

In addition, the Ogivenwand in the region of the cavity has at least one predetermined breaking point. This breaking point can z. B. be realized as a circumferential edge on the wall of the cavity. An edge is a sharp transition of material thickness that is capable of inducing material failure under load at this point. This can also be done by notches, so a defined recess or depression in the wall. These predetermined breaking points serve as predetermined zones in which material failure is initiated or promoted. Even rounded notches or edges can form a predetermined breaking point in the sense of the invention, since there is a smaller wall thickness in this area. In this case, the failure does not necessarily have to start as a crack from the edge or notch, but instead the notch facilitates a folding of the material in the present case, whereby the crack in the outer skin of the ogive can arise. The tip portion of the projectile can thus deform mushroom-shaped when hitting the target and thus initiate a further deformation of the projectile. The earlier an initial deformation occurs when hitting a resistor used, the faster deformed in the desired manner, the entire Ogive, so that a breakdown of the bullet through a protective vest such as the police uses, is prevented.

When such a projectile strikes a protective vest or other objects with sufficient resistance, a portion of the kinetic energy is converted into deformation energy. The projectile is deformed and the projectile cross-section increases, thereby reducing the specific energy of the impinging projectile such that a strike of the projectile, e.g. through a protective vest can not be done.

Preferably, the notch / edge or a plurality of spaced apart notches / edges are annularly guided around the circumference of the cavity. This facilitates symmetrical and defined mushrooming, whereby the number, geometry and arrangement in the cavity can be determined experimentally by a person skilled in the art as required. It has proven in projectiles 9 mm para three evenly distributed in the cavity ring notches or edges as effective.

In a preferred embodiment of the invention, the wall of the cavity at the top of the projectile on the smallest wall thickness. The small wall thickness at the top makes it possible for the projectile to deform sufficiently early and quickly on impact. Since the tip makes the first contact with the target, it is decisive for the overall deformation of the projectile, the faster it colums, the faster the projecting head surface of the projectile increases, thus a large deformation on impact of the projectile also leads to an enlarged one Levels cross-section. This can dissipate more energy, which further increases the cross-section, which prevents penetration or threading through the fibers from the projectile in the vest. In this way it is better ensured that there is no penetration of the projectile through a protective vest. The preferably flattening of the bullet point is also helpful here.

In a particularly preferred embodiment, the front portion of the projectile has a lower hardness than the rest of the projectile. In particular, a front tip region is provided on the ogive, in which the ogive wall has a lower hardness than the cylindrical region and preferably as the rest of the ogive. If the lower hardness, for example, by a particular carried out after pressing local heat treatment of the tip portion, z. B. by means of inductive heating, is produced, the bullet in one piece, d. H. from a single material, eg. A copper alloy such as Tombak, in particular MS95, CuZn5 or another copper wrought alloy with equivalent technological properties as Tombak or a soft iron material such as C4C; formerly QSt 32-3. So it is only a pressing process and possibly a local heat treatment necessary to achieve certain hardness properties on certain areas of the projectile. The lower hardness of the tip of the projectile compared to the cylindrical core region allows the tip to be sufficiently deformed. This leads in particular to the abovementioned features of the invention to a further reduced impact force, which likewise prevents a breakdown by protective vests. The local heat treatment is particularly important here, because after pressing the particularly heavily reshaped Ogive is solidified, so would form the hardest area of the projectile. Also, it would not be possible to take the entire bullet the hardness, since the cylindrical portion and the rear portion of the ogive must be sufficiently strong, so that a reproducible internal ballistics, no detachment of metal parts and the feeding functions of the weapon are guaranteed.

In order to achieve an improved reproducible internal and external ballistic behavior of the projectile, in one embodiment of the invention, the bottom of the projectile has a recess in the mostly solid cylindrical region, which is in particular conical or frusto-conical and / or flattened towards the cylindrical region , The recess ensures an increase in the powder volume of the Cartridge. Production-related fluctuations in the powder quantity, depending on the quality of the particular TLP lot to be processed, can occasionally result in gas pressure peaks, which can have a negative effect on the internal ballistic behavior of the cartridge. By the dome or recess in the bullet tail and the consequent increase in the powder space these fluctuations can be better compensated by the thus created, larger total powder chamber volume, resulting in an improved internal ballistic behavior of the cartridge with this projectile. Especially in the case of cartridges 9 mm para, the volume ratio of filling space to space occupied by the powder is particularly small, ie even small fluctuations in the filling quantity or batch-dependent burning rate of the powder lead to different pressures and thus projectile velocities, which in turn have an influence on the projectile deformation and penetration capability of the projectile.

In an advantageous embodiment of the invention, the projectile has a one-piece construction, in particular of a non-toxic material such as a copper alloy. This construction allows an economic production of the projectiles of a single material in one or more pressing steps, for. B. from a copper or soft iron wire. By eliminating a shell for the bullet, components and thus manufacturing steps can be reduced. Furthermore, the disposal is cheaper because no substances must be separated. Finally, the emergence of environmentally harmful lead dust by projectiles on the shooting range is completely prevented.

The claimed dimensions and materials of a projectile surprisingly lead to compliance with the standard "Technical Guidelines (TR) cartridge 9 mm x 19, reduced in pollutants", in particular as of: September 2009

Preferably, the projectile is complete or at least substantially of a material z. B. soft iron, which has a specific gravity of less than 8 g / cc. It is a particularly inexpensive, easy to process non-toxic material

Preferably, an outer coating consisting of copper and / or tin is applied. This prevents, especially in low-carbon soft iron, the risk of friction welding, which would worsen the bullet-run friction pairing to greater friction out. The coating is preferably applied electrolytically, in particular in the order copper-tin. The coating thickness is preferably 0.03 0.05 mm in total.

Further advantages will become apparent from the following description and the accompanying drawings. Likewise, according to the invention, the features mentioned above and even further can be used individually or in any desired combinations with one another. The mentioned embodiments are not exhaustive and have exemplary character.

That in the FIG. 1 on an enlarged scale projectile 1 for practice cartridges 9 mm para. is divided into an ogive 2 with a front tip region 21 and a rear cylindrical region 3. The ogive 2 extends arcuately in the direction of the tip 5 of the projectile, wherein the foremost tip region in this example is not flattened in the weft direction. A flattened tip region 10, on the one hand, provides for precise ballistic flight behavior and, on the other hand, helps initiate sufficient deformation of the tip region 21 when hitting a target.

In the Ogive 2 is the cavity 9, which is covered by the Ogivenwand 8. On the Ogivenwand 8 of the cavity 9 predetermined breaking points 81, 82, 83 are provided in the form of edges or notches, which extend along a circumference around the projectile axis A around.

The height of the cavity 9 in the ogive 2 substantially corresponds to the height of the ogive. The top 5 of the projectile has the lowest Ogivenwonddicke. Since solidification can occur in this area, for example as a result of forming processes during manufacture, the tip 5 or the tip region 21 is preferably heat-treated in order to achieve lower hardness in this area. For this purpose, a targeted heat treatment such as inductive heating with the hardening can be degraded.

Umformungsbedingt has after pressing the bullet of a copper wire of the cylindrical part - compared to the base material relatively large - Vickers hardness of about 110 HV and the Ogive a Vickersharte of up to about 130 HV. The latter is reduced by heat treatment to 80 HV5 ± 20 HV5 in the tip area. This is hard enough for proper feeding of the cartridges and soft enough to prevent penetration of the protective vests.

The bottom 6 of the projectile 1 has in the center a frustoconical depression 7, which is flattened towards the cylindrical region 3.
In the top 5 is left by the forming process, a small residual opening in the Ogivenspitze, which serves as a flattening.

Claims (14)

1. A metallic projectile (1) for practice cartridges, in particular for self-loading weapons, comprising a cylindrical rear area (3) and an arc-shaped front ogive (2) of the projectile, wherein a hollow space (9) encompassed by an ogive wall (8) is arranged in the ogive and the projectile comprises a single-piece structure,
   characterized in that
   the front area (2; 21 of the projectile comprises a lower hardness than the rest of the projectile and is submitted to a local heat treatment;
   a front tip area (21) is provided on the ogive (2), in which tip area the ogive wall (8) comprises a lower hardness than the cylindrical area (3) and preferably than the rest (22) of the ogive;
   the cylindrical area comprises a Vickers hardness of 110 HV5 +/- 10 HV5;
   the ogive wall comprises a Vickers hardness of 80 HV5 +/- 20 HV5 in the front tip area;
   the projectile is manufactured in caliber 9 mm Para, .45ACP, .40S&W or .357Mag;
   the recess in the cylindrical area occupies a volume comprised between 10 and 20 mm³, preferably between 12 and 17 mm³ and in particular preferably about 14 mm³;
   the front tip area represents approximately the front third and/or the front 2-4 mm, in particular 2.5-3.5 mm of the ogive.
2. A projectile according to claim 1, characterized in that this one is made of a non-toxic material, in particular of a copper alloy, in particular tombac Ms95 or CuZn5 or a soft iron material.
3. A projectile according to one of the preceding claims, characterized in that the ogive wall (8) comprises at least one predetermined breaking point, which is preferably designed as notch (81, 83) or edge (82), in the area of the hollow space (9).
4. A projectile according to one of the preceding claims, characterized in that the notch/edge or a plurality of notches/edges spaced from each other in the direction of the projectile axis is respectively are guided around the circumference of the hollow space like a ring.
5. A projectile according to one of the preceding claims, characterized in that the front tip (5) of the ogive is oblate, in particular by means of the opening in the ogive tip which remains after the forming process, which opening has a diameter comprised between 0.5 and 0.8 mm.
6. A projectile according to one of the preceding claims, characterized in that the bottom (6) of the projectile comprises a recess (7) in the cylindrical area, which recess is in particular conical or truncated.
7. A projectile according to one of the preceding claims, characterized in that the bottom (6) of the projectile comprises a recess (7) in the cylindrical area, which recess is flattened towards the cylindrical area.
8. A projectile according to one of the preceding claims, characterized in that the hollow space essentially extends over the length of the ogive.
9. A projectile according to one of the preceding claims, characterized in that the ogive wall comprises a wall thickness of maximum 1.3 mm and minimum 0.7 mm.
10. A projectile according to one of the preceding claims, characterized in that the oblate area of the front tip of the ogive occupies a surface having a diameter comprised between 1.0 and 2.5 mm, preferably between 1.2 and 1.8 mm.
11. A projectile according to one of the preceding claims, characterized in that the projectile is made of a material, in particular soft iron, which comprises a specific weight of less than 8 g/cubic centimeter.
12. A projectile according to one of the preceding claims, comprising an outer coating consisting of copper or tin, which is preferably applied electrolytically.
13. A projectile according to one of the preceding claims, comprising an outer coating consisting of copper and tin, which is preferably applied electrolytically, in particular in the order of tin after copper.
14. Cartridge, in particular practice cartridge and/or self-loading cartridge, comprising a projectile according to one of the preceding claims.

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