EP1745260B1 - Lead-free projectile - Google Patents

Abstract

Disclosed is a small-bore projectile (100) comprising an outer jacket (5) made of tombac, a hard core (4) made of hardened steel, and a hollow jacket core (8) that is also made of tombac. The kinetic energy is substantially transmitted to the hard core (4) when a target (Z) is hit such that said hard core (4) penetrates the target (Z). The ductile jacket (5) is supported by the jacket core (8) that is located on the inside and mushrooms up into a deformed jacket (5') without fragmenting. The inventive projectile (100) is provided with a good flying behavior and a great final ballistic performance and can be produced in an entirely lead-free manner.

Description

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

Such ammunition is known in various embodiments. It can be divided into those with hard cores made of steel, those with hard cores made of dense sintered material and those with an additional medium to the hard core such as lead, aluminum and / or air. Common to this commercial ammunition usually trained as a full-coat steel shell, d.i. a clad steel cladding or a copper / zinc alloy cladding (Tombak cladding). The jacket takes on one or more cores and other media and encloses them at least liquid-tight.

From the EP-A2-0 106 411 are known a small caliber ammunition and their manufacturing process. The correspondingly optimized projectiles serve mainly as infantry combat ammunition and already have good aerodynamic properties. However, this ammunition does not have the required by snipers high ballistic final energy, which is necessary for penetrating armor. Another disadvantage is the large proportion of hard lead (98% Pb + 2% Sn) in the core, which is toxic in both the exercise ammunition as well as combat ammunition in the environment and therefore today unwanted or even prohibited in some countries.

A mantle projectile ( WO 99/10703 ) increased penetration power and accuracy has a hard core of tungsten carbide and as an additional medium a soft core of lead (Pb / Sn 60/40), which are frictionally and tightly held over a brass disc in the jacket. This prevents the escape of heavy metals and / or vapors at launch; however, a toxic effect is still present in the target area. In addition, the production of such a projectile is expensive and too expensive for mass use (Infantriemununit).

Another bullet bullet for pistols with a caliber of 9 mm is under the name SWISS P SELF 9mm Luger commercially (RUAG Ammotec, Thun / Switzerland, formerly RUAG ammunition Thun / Switzerland). Here, the projectile consists of two telescoping sleeves, the inner sleeve closed at the rear and open at the top, with the outer sleeve enclosing a large airspace. This bullet is designed only for soft targets and allows smooth shots there; it can be produced without lead.

Out DE-A1-101010113 (which forms the starting point for the preamble of claim 1) is known a mantle projectile up to caliber 15 mm, which has an ogiven or conical front portion, a cylindrical central portion and a conically tapered tail area. The ductile metallic shell encloses a pointed hard core of hardened steel or sintered metal and is more or less kept free by a shoe or quiver-like support of ductile metal or plastic. The core touches the coat only in the region of its angular shoulder line-shaped. The impact of this projectile on armored targets is good; its accuracy but it is significantly less. In particular, in an oblique impact in the target splinters and deforms the front part of the projectile shell and thereby pushes the hard core from its initially symmetrical axis position, which at least reduces the penetration power or even leads to rebounds due to the larger cross-section. In addition, the production of the projectile is expensive and can not be done with high precision due to the more or less free storage of the hard core.

It is therefore an object of the invention, a small caliber projectile (small caliber = caliber to 0.5 ") suitable for hard targets to create, which is economical to produce, has a high penetration and accuracy and releases neither at the launch nor in the target area heavy metals Bullet should contain no lead in particular in the core.The bullet jacket should also not splinter on a hard target.

The projectile according to claim 1 can be easily produced and transmits in a hard target (sheet metal) etc. almost all the kinetic energy to the hard core which breaks through the target. The mass remains 100% preserved; At the bullet hole forms from the Tombak coat a mushroom-like collar, which the original weight of the coat This is to prove that no heavy metals and / or metal vapors are released.

The same can be stated for the subject of the invention according to claim 2. This has, although there is no solid core in the cross-section hard core, a high end ballistic performance; likewise, in practical experiments no decomposition at the target was found.

In dependent claims advantageous developments of the subject invention are described.

Ballistic particularly favorable is a projectile with an ogive-like outer shape and an air space according to claim 3. It has been shown that the necessary pressing of the hard core can be done precisely and with relatively low forces. In addition, the pulse transmission of the core, after a short displacement, allows penetration of the shell with lower energy losses.

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

The flight behavior of the projectile is largely determined by the position of the center of mass, claim 5 given. The focus can be optimized by the structural design and dimensioning of the hard core and in particular the cavity (hole) in the shell core.

Alloyed tool steels are well suited for the hard core and can be processed and surface treated by conventional means. Claim 6.

As very economical and at the same time in terms of density, assembly and thermal expansion, identical materials for the outer jacket and the jacket core according to claim 7 have been found.

A constriction according to claim 8 improves the connection with the cartridge case and allows easy assembly.

The thickening of the jacket in its front area, which is specified in claim 9, reduces rebounds in the case of oblique angle bombardment against hard targets and likewise serves to determine the center of gravity of the mass.

The previously described embodiments of the projectile appear to be particularly suitable for the calibers and bullet types mentioned in claim 10.

The current requirement for lead-free projectiles is ensured in the choice of material specified in the claims; see. Claim 11. It can also be dispensed with the conventional heavy-duty filler metal, since the center of gravity can be optimally adjusted by the dimensioning of the individual components and cavities.

The invention is disclosed below with reference to drawings and exemplary embodiments.

Show it:

Fig. 1

a projectile according to the invention, installed in a known cartridge case,

Fig. 2

a sectional view through a preferred embodiment of the projectile Fig. 1 .

Fig. 3

a sectional view of an alternative solution of a lead-free projectile,

Fig. 4a

a conventional bullet (according to the state of the art) when serving at the finish

Fig. 4b

a bullet behind Fig. 2 at the serve at the finish,
and

Fig. 4c

a bullet behind Fig. 3 at the serve at the finish.

In FIG. 1 is the tip of a projectile 100 designated 1. In the reduced diameter of a peripheral constriction 6, a flange 21 is pressed, which is part of a known cartridge 20. In the cartridge 20 is a conventional explosive 24, which acts as a propellant charge for the projectile 100. In a bottom 22 of the cartridge 20, a percussion fuze 23 (SINTOX, trademark of the company RUAG Ammotec GmbH, Fürth, DE) is used.

• Die eigentliche Spitze 1 ist fiktiv; tatsächlich handelt es sich um eine Spitze in Form einer Kugelkalotte 2. Im Innern des Geschosses 100 befindet sich ein kleiner Luftraum 3, der auf Grund unterschiedlicher Radien zwischen einem Hartkern 4 und einem äusseren Mantel 5 gebildet ist. An den Hartkern 4 schliesst formschlüssig ein Mantelkern 8 an, welcher einen zentralen sacklochförmigen Hohlraum 10 aufweist. In dessen oberen Teil befindet sich der Massenschwerpunkt 7 des Geschosses. Darüber liegt eine äussere, umlaufende Ringnut 6, die hier als Durchmesser charakterisiert eingezeichnet ist; vgl. Fig. 1.

The preferred rotationally symmetrical projectile 100 is in Fig. 2 in an enlarged sectional view:

• The actual tip 1 is fictitious; in fact, it is a tip in the form of a spherical cap 2. Inside the projectile 100 is a small air space 3, which is formed due to different radii between a hard core 4 and an outer shell 5. To the Hard core 4 encloses positively a jacket core 8, which has a central blind hole-shaped cavity 10. In its upper part is the center of mass 7 of the projectile. Above this there is an outer, circumferential annular groove 6, which is here characterized as a diameter; see. Fig. 1 ,

Rear side, the end of the shell 5 is conically tapered and ends in a gradation of an angle α of 30 °, which gradation merges into an end flange 9 and the two cores 4 and 8 holds together non-positively.

The diameter K of the projectile 100, the caliber, in the present case is 5.56 mm and is of the type SS 109. The diameter 6 of the constriction is 5.45 mm. The hard core 4 weighs 4 g and is made of hardened tool steel (material according to DIN 1.5511) and was phosphated after case hardening (penetration depth = 0.3 - 0.5 mm). The surface hardness is 570 HV1.

In this exemplary embodiment, the hard core 4 has a lower conical tip of 90 °, which rests positively in a corresponding countersinking (countersinking) in the upper part of the jacket core 8. This configuration can be varied as desired; but advantageous is an analogous form of central centering effect, which facilitates the insertion or pressing of the cores and ensures the rotational symmetry of the projectile.

Also proven has a hard core 4 Tombak; this surprisingly produces an analogous end ballistic performance.

The projectiles can be produced inexpensively and largely by deep drawing and pressing with conventional fabrication equipment.

Likewise, the hard core can also be made of other materials, for example of sintered materials such as tungsten carbide. Other bullet jackets are conceivable, which have a similar ductility as Tombak. The sheath core can also be made of other materials which have an analog or higher density. For all alloys, however, attention must be paid to heavy metal precipitation during firing and at the target.

In Fig. 3 a variant of the projectile described above is shown, while the same functional parts are provided with the same reference numerals.

Unlike the object after Fig. 2 was dispensed here on the hard core. A single jacket core 8 'also fills the space of the hard core 4, Fig. 2 , out. The associated cavity 10 'is shortened relative to the cavity 10 and has a smaller diameter. As a result, the mass of the entire projectile 100 'has been increased, so that approximately the same end ballistic performance and effect is achieved in the target.

The front side of the cavity 10 'is tapered and at least almost closed, so that together with the front part of the outer shell 5 results in a compact tip when impacting the target.

• Der Hohlraum 10 bzw. 10' lässt im Geschosslauf (Gewehr) eine Querkontraktion zu, welcher gegenüber massiven Geschossen zu einer Verringerung des Verschleisses (Abriebs), insbesondere in den Zügen führt. Gleichzeitig ist die Abschussgeschwindigkeit v₀ der Geschosse 100 bzw. 100' an der Mündung höher als bei Geschossen ohne Hohlraum 10 bzw. 10'.

Measurement results, theoretical considerations and comparisons to other projectiles (prior art) show surprisingly good results in both variants:

• The cavity 10 or 10 'allows a transverse contraction in the projectile barrel (rifle), which compared to solid projectiles leads to a reduction of wear (abrasion), especially in the trains. At the same time, the firing speed v _{0 of} the projectiles 100 or 100 'at the mouth is higher than in projectiles without a cavity 10 or 10'.

The low drag coefficient c _{w of} a 5.56 mm bullet (SS109 type) according to the invention led after 570 m flight distance (NATO target) to an impact velocity of 470 m / s; The used steel plate Stanag 4172 of 3.5 mm thickness HRB 55-70 (400 N / mm ² ) and was shot through smoothly.

The precise swirl stabilization has a positive effect on the stability and reproducibility of the trajectory, even in crosswinds. The kinetic energy is higher as a result of the choice of material and the high launch speed than comparable bullets, as experiments also showed. The precision of a conventional weapon can be increased with the subject invention. For example, all fired shots (series fire) were at a target distance of 25 m in a dispersion circle of <50 mm diameter. At 300 m firing distance a standard deviation s _A <35 mm could be determined. In practice, this means that of 20 shots fired, 18 are in a circular area of 110 mm in diameter; only two floors met about 80 mm offset to the center (target point).

Also, as demonstrated by soap bombardment tests, the CICR (Comité International de la Croix-Rouge) requirements for wound ballistics are fully met, unlike many other prior art bullets.

Fig. 4a shows a conventional hard core projectile 200 (prior art) before and at impact in target Z (steel). The steel shell 50 shatters at the target Z, an existing tungsten or steel hard core 40 penetrates the target Z, while due to the high kinetic energy of the following lead core 30 is partially liquefied on impact and partially even sublimiertverdampft. This can be recognized by a cloud of vapor 30 ', which leaves traces of lead after condensation at the destination.

In projectile 200, a combination of elastic and plastic impact with high deformation work (material separation on all sides) takes place. The material of the projectile 200 splintered at the target Z and still detectable no longer corresponds to its initial weight at the muzzle.

On the other hand, on a projectile 100, Fig. 4b , which also determine identical mass at the target Z. The hard core 4 (steel or tombac) penetrates the target Z as well. The outer jacket 5 deforms mushroom-shaped at the target Z into a deformed jacket 5 'and transfers nearly 100% of the kinetic energy via its, likewise ductile jacket core 8 onto the hard core 4; There is no material decomposition, neither on the jacket 5 nor on the jacket core 8 instead. The pulse direction is retained.

Similar shows Fig. 4c : The opposite Fig. 4b modified bullet 100 'is compressed at target Z and penetrates with a now flattened tip 1'. The pulse direction is also maintained, the sheath core 8 'shifts in the impact in the air space 3, compressed and upsetting, which is here designated by 8 ".

name list

1

Tip (fictitious)

1'

flattened, compressed tip

2

spherical cap

3

Airspace (cavity)

4

Hard core (hardened steel, Tombak)

5

outer coat (Tombak)

5 '

deformed jacket 5

6

Constriction / diameter

7

Center of gravity

8th

jacket core

8th'

jacket core

8th"

compressed casing core 8 '

9

Flanging on 5

10

Cavity in 8

10 '

Cavity in 8 '

20

cartridge case

21

Flanging on 20

22

Bottom of 20

23

percussion primer

24

Explosive / propellant charge

30

lead core

30 '

Cloud of steam from Pb

40

Hard core (tungsten, steel)

40 '

Lead fumes (sublimated Pb)

50

steel jacket

100, 100 '

Missiles

200

conventional hard-core ammunition (projectile)

K

caliber

Z

Target (steel plate)

α

Angle (base angle)

Claims (11)

1. Small-bore projectile (100) with an ogival or conical front region, a cylindrical central part and a conically extending tail region, consisting of

   - an outer jacket (5) made of a copper/zinc alloy, the jacket (5) enclosing a nearly cylindrical hollow space,

   - a hard core (4) made of steel or a sintered material inserted into the hollow space of the jacket (5) towards the tip (1,1'),

   - a jacket core (8) made of a copper/zinc alloy attached with form fit to the hard core (4), with a cylindrical hollow space (10) open on the front face,

   characterized in that

   - the open face of the hollow space (10) comprising a conical front face form fitting against the hard core (4) and sealing said hard core at the front face and

   - the jacket core (8) being in contact on the periphery over its entire length and at least at the tail region of the jacket (5) is held by frictional connection.
2. Small-bore projectile (100') with an ogival or conical front region, a cylindrical central part and a conically extending tail region, consisting of

   - an outer jacket (5) made of a copper/zinc alloy, the jacket (5) enclosing a nearly cylindrical hollow space,

   - the hollow space of the jacket (5) solely containing a jacket core (8') with a hollow space (10'),

   - the jacket core (8') being in contact on the periphery over its entire length by the jacket (5) and held with an interference fit,

   characterized in that

   - the hollow space (10') comprising an aperture tapering on the front face, the inner edge regions thereof being at least partially in contact with one another.
3. Small-bore projectile according to Claim 1, with an ogive-like front region, the tip thereof being configured at least approximately in the shape of a spherical cup,

   - the cylindrical hollow space in the front inner region being defined in the shape of a spherical cup,

   - the hard core (4) at its tip also having the shape of a spherical cup,

   - the radius of the spherical cup of the hollow space being larger than the radius of the tip of the hard core, so that in the hollow space of the jacket, in the tip thereof, an air space (3) remains.
4. Small-bore projectile according to Claim 3,

   - the tail region of the hard core (4) being of conical configuration and

   - the conical tip protruding into the hollow space (10) of the jacket core (8).
5. Small-bore projectile according to one of Claims 1 to 4,

   - the centre of gravity (7) of the projectile being located in the longitudinal axis and in the region of the hollow space (10) of the jacket core (8).
6. Small-bore projectile according to Claim 1 or 3,

   - the hard core (4) consisting of an alloyed tool steel or sintered material of high density, such as tungsten carbide.
7. Small-bore projectile according to Claim 1 or 2,

   - the outer jacket (5) and the jacket core (8) consisting of the identical copper/zinc alloy.
8. Small-bore projectile according to Claim 1, 2 or Claim 5,

   - the outer jacket (5) comprising a circumferential, peripheral constriction, on which the front end (21) of a cartridge sleeve (20) is flanged.
9. Small-bore projectile according to Claim 3,

   - the material of the jacket (5) in its front region, relative to its cylindrical region and its tail region having a thickening which is at least a factor of 2.
10. Small-bore projectile according to at least one of the preceding claims,

    - said projectile having a bore of 5.56 mm (0.223" or 0.224").
11. Small-bore projectile according to at least one of the preceding claims,

    - said projectile being lead-free.

Images