High-accuracy bullet

Abstract

FIELD: small arms.SUBSTANCE: invention relates to bullets with high shooting accuracy. The bullet comprises a shell, open at the rear end, with a core placed in it and has a head ogive, leading and tail parts. The tail part comprises a concave curved surface with a radius of (1.7-2.0)d, where d is the calibre of the bullet, with a length of 45-50% of the length of the tail section of the bullet, which is (0.60-0.65)d, connecting the leading part and part of the tail part of the bullet in the form of a truncated cone with a taper of 5-7°, tapering towards the tail part. The core is mounted in a shell with a free volume depth from the cut of the tail part of the bullet to the rear surface of the core in the tail part at a distance of (0.03-0.15)d, and the length of the bullet is equal to (3.8-4.3)d.EFFECT: creating a bullet with increased firing accuracy, which is ensured by the density of the installation of its elements during assembly, the unification of assembly operations, their simplification and the reduction of their number in the manufacture of bullets for various purposes.5 cl, 4 dwg

Description

[0001] The invention relates to the field of small arms, namely to bullets, primarily of 7.62 mm caliber, with high shooting accuracy.

[0002] The field of improving cartridges has traditionally developed in the direction of increasing the accuracy and impact effect of the bullet, with the main requirement being to ensure high shooting accuracy.

[0003] There are many technical solutions for the design of bullets with increased accuracy. Each one provides a different way of securing the bullet's components relative to each other. The most common, simple, and technologically advanced method is a conical crimp on the bullet's tail.

[0004] A known sporting and hunting cartridge bullet comprises a jacket open at the rear end with a core placed within it. The bullet has a head ogive, a leading section, and a tail section, the latter being shaped like a truncated cone tapering toward the rear end. The front end of the core is flat and located at a distance of (0.3-0.6)d, where d is the bullet caliber, from the inner front wall of the jacket. A cavity of height (0.2-0.5)d is formed in the rear part of the core. It may be cylindrical or conical. A groove for crimping the neck of the cartridge case may be made on the leading section of the bullet. The overall length of the bullet is (3-4)d. [Description of the invention to the Russian Federation patent No. 2251657 of September 11, 2003, IPC F42B 30 / 02, published May 10, 2005 Bulletin No. 13]. This bullet is used in the design of a 5.56×45 mm sport and hunting cartridge, which meets the requirements for shooting accuracy.

[0005] The bullet's nose section, with its core resting on the ogive inner surface of the jacket, does not provide reliable support for the core, preventing it from moving relative to the jacket toward the bullet's tip. This can lead to a shift in the bullet's center of mass toward its tip. The unstable center of mass of such bullets negatively impacts their accuracy.

[0006] A sniper bullet for small arms cartridges is known, comprising a head ogive, a leading and a tail section, and containing a jacket with a lead jacket and a pointed core placed therein. The mass coefficient of the core is at least 0.35, the mass coefficient of the jacket is no more than 0.4 of the bullet mass, with at least 30% of the jacket mass located behind the core in the tail section of the bullet, made in the form of a truncated cone tapering towards the rear end. [Description of the invention to the patent of the Russian Federation No. 2147367 dated 23.07.1997, IPC F42B 30 / 02, F42B 12 / 06, published 10.04.2000 Bulletin No. 10]. The bullet ensures high accuracy when firing single shots.

[0007] As is well known, the manufacturing of bullet components—the jacket and core—is carried out with certain tolerances. During assembly operations, individual cores, depending on their dimensions and within the tolerance, penetrate the jacket to different depths, thereby altering the position of the bullet's center of gravity. Furthermore, as experience with the production of such bullets has shown, during assembly operations involving fitting and crimping the tail section of the bullet, alternating loads are exerted on the bullet by the working tool—from the punch in one direction and from the ejector in the opposite direction—even though the bullet is sufficiently firmly fixed in the die. As a result of these alternating forces, the core can shift in the direction of either the head or the tail section, thereby disrupting the tightness of the assembly, which negatively impacts accuracy.

[0008] A bullet of a hunting cartridge for a rifled weapon is known, having an ogive head part, a leading part and a tail part made in the form of a truncated cone, tapering towards the rear end and containing a metal shell made with a cut in the head part and open from the end of the tail part, and a lead core placed in it with a press-fit, wherein longitudinal grooves are made on the surface of the head part of the shell from its cut, and the core in the head part of the bullet partially protrudes from the shell at a distance of 0.3-0.7 caliber of the bullet, and the protruding part of the core at the top passes, in particular, into a flat front nose. [Description of the invention to the Russian Federation patent No. 2180427 dated March 19, 2001, IPC F42B 12 / 34, F42B 30 / 02, published March 10, 2002 Bulletin No. 7]. The problem of increasing the accuracy of fire and the range of reliable destruction, as well as increasing the lethal effect of the bullet, has been solved.This is achieved by having the inner surface of the jacket at the cutoff be cylindrical and mated with the inner ogive outer surface of the jacket's nose. The jacket's surface at its leading edge is conical and mated with the ogive outer surface of the jacket. During the bullet assembly process, shaped dies, to which an axial force is applied, compress the jacket and deform the ductile lead core, simultaneously shaping the core's apex profile in its protruding portion and the conical tail section of the bullet.

[0009] To implement this bullet assembly technology, using profile dies that converge simultaneously to form the bullet's core tip and conical tail, complex specialized equipment is required. This assembly method makes it difficult to ensure dimensional stability of the bullet's tail and tip during mass production and subject to fluctuations in the tolerances of its components—the diameter and length of the core and jacket.

[0010] In all the above cases, the instability of the sizes and density of the bullets negatively affects the stability of the accuracy during shooting.

[0011] However, there are technical solutions that provide more reliable fixation of the bullet elements during its assembly.

[0012] For example, a bullet of a hunting cartridge for a rifled weapon is known, consisting of a metal shell with an ogive head, leading and tail parts, and the tail part is made in the form of a truncated cone. The shell contains a lead core having a flat front and rear ends with a ratio of the diameter of the rear and front ends equal to 1.55-1.65, while the distance from the rear end of the lead core to the end of the tail of the bullet is no more than 1.5 mm, and the tail conical part of the shell is made with an internal bend having the shape of a circular truncated cone with a minimum height of 1.5 mm, a maximum base diameter of 5.15 mm and a maximum angle between the generatrix of the truncated cone and the bullet axis of 20° [Description of the invention to the patent of the Russian Federation No. 2139487 dated 29.05.1998, IPC F42B 5 / 02, published. 10.10.1999]. The internal bend of the bullet shell improves the density of the bullet mounting, which helps to increase the accuracy of fire.

[0013] The disadvantage of such a bullet is the high labor intensity of its manufacture, since the formation of the internal bend of the shell, which has the shape of a circular truncated cone, requires a large number of sequential shape-changing operations, with the required number of working tools and precise adjustment of each operation, which does not exclude the displacement of the center of mass along the length of the bullet, and this affects the accuracy of fire.

[0014] The objective of the present invention and the technical result achieved are to ensure a tight fit between bullet components during assembly, thereby further improving firing accuracy, standardizing assembly operations, simplifying them, and reducing their number during the manufacture of bullets for various purposes. It is necessary to guarantee the fixation of the bullet components relative to each other by creating the necessary stress state in their joints, exceeding the possible range of manufacturing tolerances, and by providing springback to the components during assembly.

[0015] To solve the problem and achieve the stated technical result in a bullet with increased shooting accuracy, containing a shell open from the rear end, with a core placed in it and having a head ogive, leading and tail parts, the latter contains a concave curved surface with a radius of (1.7-2.0)d, where d is the caliber of the bullet, with a length of 45-50% of the length of the tail part of the bullet, which is (0.60-0.65)d, connecting the leading part and part of the tail part of the bullet in the form of a truncated cone with a taper of 5-7 °, tapering towards the cut of the tail part, while the core is mounted in the shell with a depth of free volume from the cut of the tail part of the bullet to the rear surface of the core in the tail part at a distance of (0.03-0.15)d, and the length of the bullet is equal to (3.8-4.3)d.

[0016] Besides:

[0017] - the core is made of lead;

[0018] - the core is made of steel or hard alloy with a lead jacket;

[0019] - the shell is made with a cut in the head ogive part, and the core is made of lead with a flat front nose and a part protruding beyond the shell cut with a length of (0.025-0.050)d;

[0020] - the leading part includes on its surface an annular rectangular knurling or ribbing with a width of (0.17-0.22)d and a depth of (0.96-0.99)d.

[0021] The essence of the invention is explained by drawings, where:

[0022] - Fig. 1 shows the general view of a bullet with increased shooting accuracy;

[0023] - Fig. 2 shows the design of the bullet of Fig. 1 in a sports sniper version;

[0024] - Fig. 3 shows the design of the bullet of Fig. 1 with increased penetration;

[0025] - Fig. 4 shows the design of the bullet of Fig. 1 in a hunting version.

[0026] The following designations are used in the drawings:

[0027] R - radius of a concave curved surface;

[0028] d - bullet caliber;

[0029] - bullet length;

[0030] - the length of the tail of the bullet;

[0031] - the length of a concave curved surface;

[0032] - the depth of free volume from the cut of the tail of the bullet to the rear surface of the core;

[0033] - the length of the part of the flat front nose of the core protruding beyond the cut of the shell;

[0034] - width of rectangular knurling or ribbing;

[0035] - the depth of rectangular knurling or ribbing.

[0036] A bullet with increased shooting accuracy contains a shell 1, open at the rear end, with a core 2 placed in it and having a head ogive 3, a leading 4 and a tail 5. The tail part 5 contains a concave curved surface 6, with a radius R equal to (1.7-2.0)d, where d is the caliber of the bullet, with a length comprising 45-50% of the length of the bullet's tail equal to (0.60-0.65)d, connecting the leading part 4 and the fragment of the tail part of the bullet 5 in the form of a truncated cone 7 with a taper of 5-7°, tapering towards the cut 8 of the tail part 5, while the core 2 is mounted in the shell 1 with a depth free volume from the cut 8 of the tail section 5 of the bullet to the rear surface 9 of the core 2 in the tail section 5 at a distance of (0.03-0.15)d, and the length of the bullet equals (3.8-4.3)d.

[0037] Additionally, the core 2 of the bullet can be made predominantly of lead. Or the core 2 can be made of two elements - steel or hard alloy - with a predominantly lead jacket 10 (i.e., the steel or hard alloy core 2, being composite, includes a lead jacket 10). Or the shell 1 of the bullet is made with a cut 11 in the head ogive part 3, and the core 2 is made predominantly of lead with a flat front nose 12 and a part protruding beyond the cut 11 of the shell 1 length (0.025-0.050)d. In addition, the leading part 4 of the bullet includes on its surface an annular rectangular knurling (or ribbing) 13 with a width equal to (0.17-0.22)d and depth (0.96-0.99)d.

[0038] Let us analyze the essential features of the invention and their developing features.

[0039] Performing bullet assembly operations using a special punch concave along a radius R equal to (1.7-2.0)d of a curved surface of length equal to 45-50% of the length The tail section 5 of the bullet, which is (0.6-0.65)d, connecting the leading section 4 and a fragment of the tail section 5 of the bullet in the form of a truncated cone 7 with a taper of 5-7º, tapering towards the cut 8 of the tail section increases the density of the mounting of the bullet elements due to an additional clearly expressed radial and axial effect directed towards the head ogive section 3 of the bullet and acting on the lead core 2 or the lead jacket 10 of the steel or hard-alloy core 2 during the crimping operation of the tail section 5 of the bullet. The obtained geometric parameters of the tail section 5 of the bullet, in comparison with a typical conical one, additionally increase the length of the leading section 4 of the bullet, which, together with the increase in the mounting density, has a positive effect on improving the accuracy of fire.

[0040] The stated design parameters of various bullets are optimal for solving the assigned task, and changing any of them leads to a decrease in the shooting accuracy characteristics.

[0041] The tail section comprises a concave curved surface 6 with a radius of (1.7-2.0)d. Decreasing the radius R to less than 1.7d reduces the radial and axial force from the crimping punch on the lead core 2 or lead jacket 10, thereby reducing the packing density during crimping of the tail section 5 of the bullet. Increasing the radius R to more than 2d reduces the length of the leading section 4 of the bullet and, accordingly, reduces the accuracy of fire.

[0042] Length of curved surface less than 45% or an increase of more than 50% of the length The tail section of the 5th bullet, equal to (0.6-0.65)d, changes the location of its center of mass in one direction or another from the optimal one, and this affects the accuracy of fire.

[0043] The tail cone of the bullet is less than 5° and more than 7°, which worsens its aerodynamic characteristics, leads to a loss of speed and reduces crosswind resistance.

[0044] Installation of a lead core 2 or a lead jacket 10 in a shell 1 with a free volume depth from the cut 8 of the tail part 5 of the bullet to the rear surface 9 of the core 2 or its jacket 10 in the tail part 5 at a distance Calculations and experiments have shown that a free volume of (0.03-0.15)d ensures that the bullet's center of mass is positioned optimally relative to the rear end, and any change in this value will reduce accuracy. A free volume reduction of less than 0.03d can result in lead leakage from jacket 1 in tail section 5 during bullet assembly, which is unacceptable. An increase of more than 0.15d can shift the bullet's center of mass away from the optimal position, negatively impacting accuracy.

[0045] Length deviation a bullet equal to (3.8-4.3)d in one direction or another beyond the specified values ​​reduces the accuracy of fire, both for conventionally “short” and conventionally “long” bullets.

[0046] The stated parameters of the bullet with increased shooting accuracy, in addition to ensuring the tightness of the bullet's components during assembly, provide the ability to standardize assembly operations, simplify them, and reduce their number when manufacturing bullets for various purposes. These can be bullets with a lead core 2, or the core 2 can be made of steel or carbide with a lead jacket 10, or the core 2 of the bullet can be made of lead with a flat front nose 12. Length The part of the flat front nose 12 of the core 2 protruding beyond the cut 11 of the shell 1 should not exceed (0.025-0.05)d. An increase in length may lead to deformations of the nose 12 during wiping of the bullet in the wiping drum after assembly and during cartridge mounting operations, thereby changing the length of the bullet. , and this begins to change the optimal location of the center of mass and, as a result, reduces the accuracy of fire.

[0047] In addition, on the surface of the leading part 4 of the bullet, an annular rectangular knurling (or ribbing) 13 wide is performed equal to (0.17-0.22)d and depth A value equal to (0.96-0.99)d ensures the transmission of an additional compacting effect through the shell 1 to the core 2 or its jacket 10, which has a positive effect on the bullet mounting density, makes the force of bullet extraction from the case during firing more stable, and makes the resistance of movement along the barrel more stable. The knurling improves the fixation of the bullet in the case during cartridge mounting, since the upper edge of the case neck (conditionally not shown) is crimped into this knurling (or ribbing) 13. Deviation of the knurling width from the minimum value worsens the stability of the crimping of the edge of the case neck, which leads to a dispersion of the force of bullet extraction from the case, and a deviation on the greater side reduces the length of the leading part of the bullet, which cuts into the rifling of the barrel, which negatively affects the accuracy of fire.

[0048] The above-mentioned essential and developing features of the invention, being unified for bullets of various purposes - from sniper to sport and hunting - reduce the number of assembly operations, unify and simplify them, but most importantly, ensure a guaranteed density of installation of bullet elements during their assembly.

[0049] During the development of the design of bullets with a lead core (2) and a hard-alloy (steel) core (2) with a lead jacket (10), accuracy tests were conducted on the cartridges. Firing tests were conducted from a ballistic barrel at distances of 100 and 300 meters in three series of 10 shots.

[0050] When firing cartridges with a lead core bullet from a ballistic barrel (Fig. 2), the accuracy of fire - the average dispersion diameter was:

[0051] - at a distance of 100 meters Psr=1.9 cm, which is 0.65 MOA;

[0052] - at a distance of 300 meters Psr=6.2 cm, which is 0.71 MOA, R100 sr=4.0 cm.

[0053] For comparison, similar cartridges from another manufacturer provide 54% less accuracy R100 avg=8.8 cm.

[0054] When firing from a ballistic barrel cartridges with a bullet with a hard-alloy core and a lead jacket (Fig. 3), the accuracy of fire - the average dispersion diameter at a distance of 100 meters was Psr = 2.7 cm, which is 0.93 MOA.

[0055] For comparison, similar cartridges with a knurled bullet and a conventional conical tail section provide 27% less accuracy at a distance of 100 meters Psr=3.7 cm.

[0056] When firing from a ballistic barrel cartridges with a bullet with a lead core and a cut in the head ogive part of the shell with a protruding part of the core, made with a flat front nose (Fig. 4), the accuracy of fire - the average dispersion diameter at a distance of 100 meters was Psr = 2.8 cm.

[0057] For comparison, similar cartridges with a bullet with a protruding lead nose according to Russian patent No. 2180427 provide a 10% lower accuracy of Psr=3.1 cm at a distance of 100 meters.

[0058] As a result of solving the assigned problem, a bullet with increased shooting accuracy was created, which is ensured by the density of installation of its elements during assembly, the unification of assembly operations, their simplification and reduction in their number during the manufacture of bullets for various purposes.

Claims

1. A bullet comprising a shell open at the rear end with a core placed therein and having a head ogive, a leading and a tail section, characterized in that the tail section contains a concave curved surface with a radius of (1.7-2.0)d, where d is the caliber of the bullet, with a length of 45-50% of the length of the tail section of the bullet, which is (0.6-0.65)d, connecting the leading section and a fragment of the tail section of the bullet in the form of a truncated cone with a taper of 5-7°, tapering towards the cut of the tail section, wherein the core is mounted in the shell with a free volume depth from the cut of the tail section of the bullet to the rear surface of the core in the tail section at a distance of (0.03-0.15)d, and the length of the bullet is equal to (3.8-4.3)d.

2. A bullet according to paragraph 1, characterized in that the core is made of lead.

3. A bullet according to paragraph 1, characterized in that the core is made of steel or hard alloy with a lead jacket.

4. A bullet according to claim 1, characterized in that the shell is made with a cut in the head ogive part, and the core is made of lead with a flat front nose and a part protruding beyond the shell cut by a length of (0.025-0.05)d.

5. A bullet according to claim 1, characterized in that the leading part includes on its surface an annular rectangular knurling or ribbing with a width of (0.17-0.22)d and a depth of (0.96-0.99)d.

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