JP4713577B2 - Lead free bullet - Google Patents

Description

  The present invention relates to a lead-free, small-caliber jacketed bullet.

  Such ammunition is known in various configurations. This can be classified as having a hard core made of steel, having a hard core made from a dense sintered material, and having a medium such as lead, aluminum, and / or air in addition to the hard core. . Attached to this commercially available ammunition is a steel jacket, typically configured as a full jacket, ie a plated steel jacket or a jacket made from a copper / zinc alloy (Tomback jacket). In this context, the jacket receives one or more cores and further media and surrounds the cores and media in at least a liquid-tight manner.

  The firearm ammunition and its manufacturing process are known from EP-A-0106411. The correspondingly optimized bullets are mainly used as live ammunition for infantry and already have excellent aerodynamic characteristics. This ammunition, however, does not have the high final ballistic energy required by the shooter that is required to penetrate the armor plate. A further disadvantage is the large amount of hard lead in the core (98% Pb + 2% Sn), which has a toxic effect on the environment in both air and live ammunition and is therefore not preferred today. It is even banned in some countries.

  A bullet with jacket with higher penetration and target accuracy (WO 99/10703 pamphlet) has a hard core made of tungsten carbide and a soft core made of lead (Pb / Sn60 / 40) as an additional medium. These are then held in the jacket by an interference fit in an airtight manner via a brass disc. Thus, heavy metal and / or steam leakage during launch is prevented. However, there is still a toxic effect in the target area. In addition, the production of such bullets is expensive and too expensive for mass use (infantry ammunition).

  A further jacketed bullet for a 9 mm caliber pistol is commercially available under the name SWISS P SELF 9 mm Luger (RUAG Ammotec, Thun / Switzerland, formerly RUAG Ammunition Thun / Switzerland). In this case, the bullet consists of two sleeves that are pushed together, the inner sleeve being sealed at the tail and open upwards, enclosing a large gap with the outer sleeve. However, this bullet is exclusively for soft targets, in which case it can penetrate smoothly and can be manufactured as lead-free.

  A jacketed bullet with a caliber of up to 15 mm, comprising an ozive-shaped or conical front region, a cylindrical central part and a conically extending tail region, is described in DE 10710113 A1. Are known. A ductile metallic jacket surrounds a pointed hard core, made of hardened steel or made of sintered metal, made of ductile metal or made of synthetic material, a shoe-like or sheath-like support Will be held more or less freely. The core is in linear contact exclusively in the area of the jacket and its angular shoulder. The penetrating action of this bullet on the armor plating target is good. However, its target accuracy is significantly reduced. Especially when hitting the target at an angle, the front part of the bullet jacket tears and deforms, and as a result pushes the hard core out of its initial axis of symmetry, which at least increases the penetration performance when the effective cross-sectional area is larger. Causes a drop or even a jump. In addition, the manufacture of bullets is expensive and may not be accomplished with high accuracy due to the more or less free placement of hard cores.

  The object of the present invention is therefore to provide a small-caliber bullet suitable for rigid targets (small-caliber = 0.0) that is economical to manufacture, has high penetration performance and target accuracy, and does not release heavy metals upon launch or in the target area. 5 caliber (less than about 13 mm). The provided bullets are specifically intended to contain no lead in the core.

  The bullet according to claim 1 is easy to manufacture and, in a hard target (sheet metal) etc., transfers most of the total kinetic energy to the hard core, which penetrates the target. In this connection, the mass is kept at 100% and a tomback jacket forms a mushroom-like ring that matches the original weight of the jacket at the hole opened by the bullet.

  Thus, it has been found that heavy metals and / or metal vapors are not released.

  The same applies to the subject of the invention according to claim 2. This demonstrated high final ballistic performance, and despite the absence of a hard core across the entire surface in cross section, no crushing at the target was observed in the field test.

  Advantageous developments of the subject matter of the invention are disclosed in the dependent claims.

  A bullet having an Ogive-like profile and voids according to claim 3 is particularly advantageous with regard to ballistic properties. It has been found that the required hard core press-in can be performed accurately and with relatively little force. In addition, core pulse transmission via a short travel path allows penetration of the jacket with lower energy loss.

  The embodiment according to claim 4 is very advantageous for the transmission of a central pulse from the jacket core to the hard core.

  The flight behavior of the bullet is given by a significant part, the position of the center of gravity (claim 5). The center of gravity can be optimized by structural design and sizing of the hard core, and in particular by structural design and sizing of the cavities (holes) in the jacket core.

  Alloy tool steels are well suited for hard cores and can be machined and surface treated by conventional means (claim 6).

  The same material for the outer jacket and jacket core according to claim 7 has been found to be very economical and also advantageous in terms of density, assembly and thermal expansion.

  The constriction according to claim 8 improves the connection to the cartridge sleeve and allows its simple assembly.

  The thick part in the front area of the jacket according to claim 9 serves to suppress jumping at the hard target during acute angle launch and to determine the center of gravity.

  The bullet embodiment described above appears to be particularly suitable for the caliber and bullet types cited in claim 10.

  The current demand for lead-free bullets is guaranteed by the choice of materials disclosed in the claims. See claim 11. Because the position of the center of gravity can be optimally adjusted by sizing individual components and cavities, standard filling materials made of heavy metal in conventional bullets can also be omitted.

  Hereinafter, the present invention will be disclosed with reference to embodiments and drawings.

  In FIG. 1, the tip of the bullet 100 is indicated by 1. The flange 21 is inserted into the reduced diameter of the peripheral constriction 6, which is a component of the cartridge 20 known per se. A standard explosive 24 is located within the cartridge 20, which acts as a propellant for the bullet 100. An impact fuse 23 (a trademark of SINTOX, company RUAG Amotec GmbH, Furth, DE) is inserted into the base 22 of the cartridge 20.

  In FIG. 2, a suitable rotationally symmetric bullet 100 can be seen in an enlarged cross-sectional view.

  The actual tip 1 is virtual, which is actually a tip in the shape of a spherical cup 2. A small gap 3 is located inside the bullet 100, and this gap is formed by the difference in radius between the hard core 4 and the outer jacket 5. The jacket core 8 is attached to the hard core 4 by a shape fit, which further has a central cavity 10 in the form of a blind hole. The center of gravity 7 of the bullet is located in the upper part of the cavity. The outer peripheral annular groove 6 is located above its center of gravity, which is illustrated here and depicted as a diameter. Please refer to FIG.

  At the tail, the end of the jacket 5 tapers conically and terminates at an angle α of 30 ° at the stepped portion, which joins the end flange 9 and connects the two cores 4 and 8 together. Both are held by interference fit.

  The diameter, or caliber, of the bullet 100 indicated by K is 5.56 mm in this case and is of the SS109 type. The diameter 6 of the constriction is 5.45 mm. The hard core 4 weighs 4 g, is made of hardened tool steel (material according to DIN 1.5511), and is phosphated after carburizing (penetration = 0.3-0.5 mm). The surface hardness is 570 HV1.

  In this embodiment, the rigid core 4 has a 90 ° lower conical tip, which is completely rested in a corresponding recess (counter sink) in the upper part of the jacket core 8. Yes. This configuration may be arbitrarily changed. However, a similar form of centering action is advantageous, which facilitates core insertion or press-fit and further ensures bullet rotational symmetry.

  A hard core 4 made from tomback has also proven advantageous. Surprisingly, this results in nearly equivalent final ballistic performance.

  Bullets can be manufactured by standard manufacturing equipment and substantially by deep drawing and pressing.

  The hard core may also be made from other materials, for example from sintered materials such as tungsten carbide. Other bullet jackets that have approximately the same ductility to tomback are also conceivable. The jacket core may also be composed of other materials having a density that is approximately equal or greater. However, in any alloy, consideration must be given to the deposition of heavy metals at launch and at the target.

  FIG. 3 shows a modification of the above-mentioned bullet, and in this connection, the same functional parts are given the same reference numerals.

  In contrast to the subject according to FIG. 2, in this case the hard core is omitted. The single jacket core 8 'likewise occupies the space of the hard core 4 in FIG. The associated cavity 10 'is shortened compared to the cavity 10 and has a smaller diameter. As a result, the overall mass of the bullet 100 'is increased so that approximately the same final ballistic performance and effect is achieved at the target.

  At the front, the cavity 10 'tapers and is at least largely closed, resulting in a compact tip when hitting the target, along with the forward portion of the outer jacket 5.

  In both variants, the measurement results, theoretical considerations, and comparison with other bullets (prior art) show exceptionally good results.

The cavities 10 and / or 10 'allow lateral contraction in the barrel (rifle), which leads to a reduction in wear (wear), particularly in the rivets, compared to solid bullets. At the same time, the firing speed V ₀ of the bullet 100 and / or 100 ′ at the muzzle exceeds the bullet lacking the cavity 10 and / or 10 ′.

The low drag coefficient C _d through a 570 m flight distance (NATO target) of a 5.56 mm bullet (SS109 type) according to the present invention still results in a collision speed of 470 m / sec. The steel plate used was Stanag 4172 with a thickness of 3.5 mm with a hardness of 55-70 HRB (400 N / mm ² ) and was smoothly perforated.

Precise spin stabilization has a positive effect on flight path stability and reproducibility, even with crosswinds. As a result of the choice of material and high firing speed, the kinetic energy is also greater than comparable bullets, as also revealed by the tests. The subject matter of the present invention can increase the accuracy of standard weapons. Thus, for example, any shots fired at a target distance of 25 m (repeated fire) were located within a scatter circle having a diameter of less than 50 mm. At a launch distance of 300 m, a standard deviation S _D <35 mm was observed. In practice, this means that 18 of the 20 firing shots are located within a 110 mm diameter circular surface, with only two bullets hitting about 80 mm from the center (target).

  The ICRC (Red Cross International Commission) requirements for wound ballistic properties are also fully met, as opposed to a number of other bullets according to the prior art, as revealed by tests on soaps.

  FIG. 4a shows a conventional hard core bullet 200 (prior art) before and when impacting a target Z (steel). The steel jacket 50 ruptures at the target Z and the hard core 40 made of tungsten or steel penetrates the target Z, while due to the high kinetic energy, the subsequent lead core 30 is partially liquefied and undergoes a collision. Even partially vaporized by sublimation. This can be confirmed by the vapor cloud 30 ', which also leaves a trace of lead on the target after its condensation.

  In the bullet 200, a combination of elastic and plastic collision and high deformability occurs (material fracture on all sides). The material of the bullet 200 that can tear at the target Z and still be recognized does not match the original weight at its muzzle.

  In contrast, one bullet 100 in FIG. 4b can see the same mass at target Z. In this connection, the hard core 4 (steel or tomback) also penetrates the target Z. The outer jacket 5 spreads in a mushroom shape at the target Z to become a deformed jacket 5 ′, and similarly, almost 100% of the kinetic energy is transmitted to the hard core 4 through the ductile jacket core 8. Neither the jacket 5 nor the jacket core 8 is crushed. The pulse direction remains the same.

  FIG. 4c shows a similar diagram. The bullet 100 ′ modified compared to FIG. 4 b collapses at the target Z and penetrates by the tip 1 ′, which is now flat. The pulse direction is also maintained. The jacket core 8 'is displaced into the gap 3 on impact and is compressed and crushed, here indicated by 8 ".

A bullet according to the invention fitted in a cartridge sleeve known per se. FIG. 2 is a cross-sectional view of a preferred embodiment of the bullet of FIG. FIG. 6 is a cross-sectional view of an alternative solution for lead-free bullets. A conventional bullet (according to the prior art) when hitting a target. 3 is a bullet according to FIG. 2 when hitting a target. FIG. 4 is a bullet according to FIG. 3 when hitting a target.

Explanation of symbols

1 Tip (virtual)
1 'Flattened tip 2 Spherical cup 3 Cavity
4 Hard core (hardened steel, tom back)
5 Outer jacket (Tomback)
5 'deformation jacket 5
6 Narrowed part / diameter 7 Center of gravity 8 Jacket core 8 'Jacket core 8 "Crushed jacket core 8'
9 Flange 10 8 Cavity 10 '8' Cavity 20 Cartridge Sleeve 21 20 Flange 22 20 Base 23 Impact Fuse 24 Explosive / Propellant 30 Lead Core 30 'Steam Cloud of Pb 40 Hard Core (Tungsten, Steel )
40 'Lead vapor (sublimation Pb)
50 Steel jacket 100, 100 'Bullet 200 Conventional hard core ammunition (bullet)
K caliber Z target (steel plate)
α angle (base angle)

Claims (11)

A small caliber bullet (100) having an ozive or conical front region, a cylindrical central portion, and a conical extending tail region,
An outer jacket (5) made of copper / zinc alloy surrounding the cavity (3);
A hard core (4) made of steel or sintered material, inserted into the cavity (3 ) of the outer jacket (5) towards the tip;
Comprising a jacket core (8) made of a copper / zinc alloy having a cylindrical central cavity (10) open at the front face and attached to the hard core (4) by shape fitting;
The open face of the central cavity (10) of the jacket core (8) comprises a conical front face and rests completely on the hard core (4) and seals the hard core at the front face;
Jacket core (8) is in contact with the outer jacket at the end region of the outer surface and in at least the outer jacket over the entire length of its (5) (5), is held by interference fit and a small-diameter projectile. A small caliber bullet (100 ') having an ozive or conical front region, a cylindrical central portion, and a conical extending tail region,
Consisting of an outer jacket (5) made of copper / zinc alloy surrounding the cavity (3),
Cavity of the outer jacket (5) is, 'jacket core having a (8 central cavity (10)') and the dedicated al housing,
The central cavity (10 ′) of the jacket core (8 ′) is provided with openings that taper at the front surface, and their inner end regions are at least partially in contact with each other;
Jacket core (8 ') is in contact with the outer jacket at the outer surface over the entire length of its (5), is held by interference fit and a small-diameter projectile. Having an Ojive-like front region, the tip of the Ogibe-like front region being configured in the shape of at least a substantially spherical cup,
A cylindrical cavity in the front interior region is defined in the shape of a spherical cup;
The hard core (4) also has a spherical cup shape at the tip,
The small caliber bullet according to claim 1, wherein the radius of the hollow spherical cup is larger than the radius of the tip of the hard core, and the cavity of the outer jacket remains in the cavity tip at the tip of the cavity. The tail region of the hard core (4) has a conical configuration;
4. A small caliber bullet according to claim 3, wherein the conical tip projects into the central cavity (10) of the jacket core (8). 5. A small caliber bullet according to claim 1, wherein the bullet center of gravity (7) is located on the longitudinal axis and in the region of the central cavity (10) of the jacket core (8). .   The small-caliber bullet according to claim 1 or 3, wherein the hard core (4) is made of a high-density sintered material such as alloy tool steel or tungsten carbide.   The small caliber bullet according to claim 1 or 2, wherein the outer jacket (5) and the jacket core (8) are made of the same copper / zinc alloy.   The outer jacket (5) comprises a circumferential peripheral constriction, the front end (21) of the cartridge sleeve (20) being fitted into the peripheral constriction. Small caliber bullet.   4. A small caliber bullet according to claim 3, wherein the material of the outer jacket (5) has a portion that is at least twice as thick in the front region of the outer jacket as compared to the cylindrical region and the tail region.   10. A small caliber bullet according to at least one of the preceding claims, wherein the bullet has a caliber of 5.56 mm (0.223 inches or 0.224 inches).   The small caliber bullet according to at least one of claims 1 to 10, wherein the bullet is lead-free.

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