Two-element bullet

Abstract

This utility model relates to small arms ammunition, specifically bullets for cartridges with sniper and other high-precision characteristics, designed to engage armored targets and / or located behind obstacles. The technical result consists of increasing the reliability and rigidity of the connection between the core and the jacket. A two-element bullet comprises a jacket and a core secured within the jacket. The jacket has an axial blind channel for seating the core. A groove is formed on the inner surface of the axial blind channel. The groove is spiral. After installation, a volume is retained between the end of the core and the bottom of the axial blind channel, communicating with the spiral groove. 3 fig.

Description

[0001] This utility model relates to small arms ammunition, specifically bullets for cartridges with sniper and other high-precision characteristics, designed to engage armored targets and / or located behind obstacles. The design relates to two-element bullets with a core housed in a metal jacket.

[0002] A bullet is known under Russian Federation patent for utility model RU 35145 U. This solution relates to armor-piercing bullets and comprises a metal jacket and core. Common features with the claimed utility model include the presence of a jacket and a core located within the jacket. However, this known solution does not disclose the inclusion of an axial blind channel in the jacket for the seating of a core with a spiral groove on its surface. The groove shape as a structural element affecting the nature of air removal and the distribution of contact pressures during core installation is also not disclosed. A disadvantage of this solution compared to the claimed utility model is the lack of design features that ensure targeted air removal along a helical trajectory and reduce the likelihood of core distortion.

[0003] Invention RU 2262651 C2 "Armor-Piercing Bullet" describes a bullet with a metal jacket and a hard core capable of armor penetration. The common features are a jacket and a core secured within it. However, this solution fails to disclose the design of an axial blind channel for the core seating with a spiral groove on its surface. This known solution focuses on other design techniques for increasing lethality and does not address the problem of ensuring more controlled air bleed during core installation due to the spiral shape of the groove. A drawback of this analog is the lack of a structural connection between the channel surface geometry and the improvement in the uniformity of the core seating.

[0004] International patent application WO 2007061318 A1 describes a bullet body made of ductile metal with a cylindrical core placed inside. Common features include a two-piece bullet design and an internal channel in the jacket for accommodating the core. However, this application fails to disclose a spiral groove on the surface of the channel. Nor does it describe the effect of the spiral groove on more uniform air displacement, reducing the formation of localized air pockets, and improving core seating stability. A drawback of this prior art application is that it does not include a structural element that ensures a helical direction of air flow along the length of the channel.

[0005] The closest prior art patent accepted as a prototype is US Patent No. 10048051 B1. The prior art discloses a two-element bullet comprising a jacket and a core secured within the jacket. The jacket has an axial blind channel for seating the core, and a groove on the surface of the channel for venting air during core installation. Common features with the claimed utility model include a two-element bullet design, the presence of a jacket, a core, an axial blind channel for seating the core, and a groove on the surface of said channel. Unlike the prior art, the claimed utility model's spiral groove provides an elongated helical air evacuation path and a more uniform distribution of contact pressures along the circumference and length of the channel, which contributes to a more stable core seating.

[0006] The technical challenge is to create a two-element bullet that, when the core is inserted into the jacket, ensures more complete removal of air from the seating area, uniform distribution of contact pressures along the length and circumference of the mating surface, and eliminates microgaps and core distortion. The technical result consists of increasing the reliability and rigidity of the core-jacket connection.

[0007] The technical result is achieved in a two-element bullet containing a shell and a core fixed inside the shell; an axial blind channel is made in the shell for seating the core, on the surface of which there is a groove made spiral.

[0008] Brief description of the drawings

[0009] Fig. 1 - general view of a two-element bullet in longitudinal section.

[0010] Fig. 2 - a shell with an axial blind channel and a spiral groove on its inner surface.

[0011] Fig. 3 - shell with spiral grooves.

[0012] The claimed utility model is a two-element bullet comprising a shell 1 and a core 2 secured within the shell 1. An axial blind channel 3 is formed in the shell 1 for receiving the core 2. A groove 4 is formed on the surface of the axial blind channel 3, wherein the groove 4 is made spiral. The spiral groove 4 forms a continuous helical path on the inner surface of the axial blind channel 3, along which air can be removed from the volume of the channel when the core 2 is installed. Due to the fact that the air outlet path is made not rectilinear, but helical, the air removal occurs more gradually and more uniformly along the length of the channel. This reduces the likelihood of the formation of localized zones of trapped air in the bottom of the axial blind channel 3 or in the areas of contact between the core 2 and the shell 1.

[0013] The spiral shape of groove 4 also promotes a more uniform distribution of contact pressures along the circumference and length of axial blind channel 3. When core 2 is installed in jacket 1, its interaction with the inner surface of the channel occurs not along a single rectilinear generatrix, but along a helical trajectory distributed along the length of the channel. This reduces the likelihood of local jamming of core 2, reduces the risk of core 2 misalignment relative to the bullet's geometric axis, and reduces the likelihood of local deformation of jacket 1. Thus, targeted air displacement ensures a tight and uniform fit between the core and jacket, thereby maintaining the integrity of the bullet. The reliability and rigidity of the core-jacket connection is increased, and the bullet also ensures more stable load transfer when interacting with an obstacle.

[0014] Compared to longitudinal grooves, spiral grooves on the inner surface of the axial blind channel of the shell offer several advantages. During core seating, the spiral groove not only acts as a passive ventilation channel but also as a guide for the consistent displacement of air from the mating cavity. This reduces the likelihood of localized air "traps" that can occur with longitudinal grooves at high press-in speeds or when the air outlet is partially blocked. Furthermore, the spiral shape increases the length of the residual air evacuation path, creating a labyrinth effect that allows air to escape in a more controlled manner and reduces the likelihood of air leakage through isolated localized gaps.At the same time, the spiral groove promotes a more uniform distribution of contact pressure between the core and jacket along the circumference and length of the fit, reduces the likelihood of core distortion, minimizes the formation of microgaps, and ensures a tighter fit between the mating surfaces. This increases the rigidity and stability of the core-jacket connection, which is especially important during bullet-to-objective interactions, when an insufficiently tight fit can cause the core to shift relative to the jacket, causing structural integrity loss and reducing load transfer efficiency.When using a spiral groove, the core and jacket work more as a single unit, the core receives stable lateral and rear support, the likelihood of its internal displacement upon impact is reduced, the shape of the bullet's nose is preserved more effectively, and a more stable transfer of the load to the target is ensured, which together helps maintain the integrity of the bullet and increase its effectiveness.

[0015] In one embodiment, the shell 1 may be made of copper, tombac, brass, or another ductile metallic material, and the core 2 may be made of steel, tungsten carbide, or another material of increased hardness. The axial blind channel 3 may be obtained by mechanical processing, including turning, drilling, mandrel-burnishing, or another method that ensures the required accuracy of the channel geometry. The spiral groove 4 may be formed on the inner surface of the axial blind channel 3 by cutting, knurling, shaping with a tool, or another technologically suitable method. In one embodiment, a small volume may remain between the end of the core 2 and the bottom of the axial blind channel 3 after the core 2 is installed, from which air is removed along the spiral groove 4 during the installation of the core 2.In another embodiment, the core 2 can be installed without a pronounced residual cavity at the bottom of the channel, while the spiral groove 4 ensures the removal of air from the gap area between the side surface of the core 2 and the inner surface of the channel during installation.

[0016] The original materials provide approximate groove depth ranges for different calibers as process examples. In particular, the range indicated for the .223 caliber (bullet diameter 5.56 mm) is 0.001-0.05 mm, for the .308 Win (bullet diameter 7.82 mm) - 0.005-0.07 mm, for the .338 (bullet diameter 8.6 mm) - 0.005-0.09 mm, for the .375 (bullet diameter 9.5 mm) - 0.007-0.09 mm, for the .408 (bullet diameter 10.3 mm) - 0.007-0.09 mm, for the 12.7 mm caliber (bullet diameter 12.9 mm) - 0.09-1 mm. The given values ​​can be used as approximate technological examples in the design and manufacture of the shell 1 and the axial blind channel 3 with the spiral groove 4. The spiral groove creates an extended helical path for air removal and promotes a more uniform distribution of contact.

[0017] An embodiment example of the utility model can be realized as follows. An axial blind channel 3 is formed in a ductile metal shell 1. A spiral groove 4 is formed on the inner surface of channel 3. Then, a core 2 is installed in the axial blind channel 3. As core 2 moves along channel 3, air is removed along spiral groove 4, and the contact between core 2 and shell 1 is distributed more evenly. As a result, core 2 occupies a more stable position in shell 1, which contributes to achieving the claimed technical result. Fig. 3 shows an example of a core with multiple spiral grooves.

Claims

A two-element bullet containing a shell and a core secured inside the shell; an axial blind channel is formed in the shell for seating the core; on the inner surface of the axial blind channel there is a groove, characterized in that the groove is made spiral, and between the end of the core and the bottom of the axial blind channel after installation of the core, a volume is retained that communicates with the spiral groove.

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