Patent Application
20140331883
A standard .50 caliber armor piercing bullet includes a copper jacket, a lead nose, and a tool steel core. The tool steel core is disposed behind the lead nose, and the copper jacket extends around the tool steel core to engage rifling of the gun barrel during firing.
When such an armor piercing bullet is fired at a target, the bullet may strike the target with an impact velocity which exceeds 800 meters per second. At such a speed, the bullet is capable of penetrating rolled homogenous armor (RHA) to a depth of approximately 2.9 cm.
An improved armor penetrating round utilizes a hollow core which contains a slug to achieve penetration effects beyond that of the above-described standard armor piercing bullet. In particular, in the improved armor penetrating round, the slug initially resides at the back of a tapered cavity within the core. When the improved armor penetrating round impacts an armored target such as an armor plate, the material of the slug decouples from the back of the tapered cavity within the core and accelerates through the tapered cavity in the direction of the armor plate. As the material of the slug slides along the tapered walls of the core within the cavity, the slug material forms a jet which provides further penetration into and perhaps through the armor plate. Accordingly, the improved armor penetrating round is capable of providing enhanced destructive and/or lethal effects beyond conventional armor piercing bullets.
One embodiment is directed to an armor penetrating round which includes an elongated core portion (e.g., a hollow tool steel core) defining a front end, an aft end, and a central cavity which extends from the aft end toward the front end. The central cavity has (i) an aft cross-sectional diameter adjacent the aft end and (ii) a front cross-sectional diameter adjacent the front end, the aft cross-sectional diameter being larger than the front cross-sectional diameter. The armor penetrating round further includes a slug portion (e.g., a pre-compacted pellet of powdered metal) which is disposed within the central cavity adjacent the aft end, and an outer jacket (e.g., a copper jacket) which extends around the elongated core portion to operate as an interface between the armor penetrating round and a gun barrel when the armor penetrating round is fired through the gun barrel.
Other embodiments are directed to ammunition and other projectiles which include such armor penetrating rounds. Yet other embodiments are directed to processes of making and using such armor penetrating rounds, and so on.
The foregoing and other objects, features and advantages will be apparent from the following description of particular embodiments of the present disclosure, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of various embodiments of the present disclosure.
An improved armor penetrating round utilizes a hollow metallic core which contains a slug to achieve penetration effects beyond that of conventional armor piercing bullets. In particular, in the improved armor penetrating round, the slug initially resides at the back of a tapered cavity within the core. When the improved armor penetrating round impacts an armored target such as a rolled homogenous armor (RHA) plate, the material of the slug (e.g., powdered metal) decouples from the back of the tapered cavity and accelerates through the tapered cavity in the direction of the target. As the slug material slides along the tapered core walls, the slug material accelerates and forms a jet which provides further penetration into and perhaps through the plate. Accordingly, the improved armor penetrating round is capable of providing enhanced destructive and/or lethal effects beyond conventional armor piercing bullets (e.g., a standard 0.50 caliber armor piercing bullet).
Each high performance armor penetrating round 24 includes an elongated core 30 which defines a cavity 32 which narrows (or tapers) from back to front, a slug 34 which is disposed within the cavity 32, and an outer jacket 36. As will be explained in further detail shortly, when such a round 24 is fired from the firing device 22 in a forward direction F (see arrow F in
As shown by the arrow L in
Each round of ammunition 40 includes a shell 42, propellant 44 which is loaded within the shell 42, and an armor penetrating round 24. When a round of ammunition 40 is loaded within the firing device 22 and fired, the propellant 44 within that ammunition round 40 ignites and propels the armor penetrating round 24 from the shell 42 and through the barrel of the firing device 22 toward the target 26. As will now be explained in further detail with reference to
As illustrated in
As further shown in
It should be understood that the slug 34 does not fully fill the cavity 32 of the core 30. Rather, there is space in front of the slug 34 (e.g., air, inert gas, a vacuum, etc.) to enable material of the slug to move in the forward direction F during impact. In some arrangements, the slug 34 has a depth D1 as measured along the central axis 54 and the cavity 32 has a depth D2 as measured along the central axis 54, where D2 is in the range of 3 to 4 times D1. For example, in certain arrangements, the slug 34 is substantially 1 cm thick (i.e., D1=1 cm) and the cavity 32 is 3 to 4 cm's thick (i.e., D2=3 to 4 cm).
It should be further understood that the composition of the slug 34 and the tapered shape of the cavity 32 are such that, upon impact of the armor penetrating round 24 with the target 26, the slug 34 easily decouples from the aft end 52 of the core 30 and disintegrates due to shearing along the inner core walls within the cavity 32 as the slug material proceeds in the forward direction F through the cavity 32 as shown in
In some arrangements, the geometry of the cavity 32 and the composition of the slug 34 are such that the material of the slug 34 is able to accelerate to at least 2 times (2×) that of the armor penetrating round 24 at initial impact velocity. For example, suppose that the impact velocity is 800 meters per second. In these arrangements, the slug material accelerates to a velocity of 1500 meters per second or higher. Other acceleration effects (e.g., 3×, etc.) are achievable by varying the geometries of the inner core walls and/or the composition of the slug 34.
As shown in
One should appreciate that several physical effects combine to provide the high performance aspects of the armor penetrating round 24. For example, the material of the slug 34 has very low yield strength. Additionally, the friction between the slug 34 and the inner walls of the core 30 does not significantly transfer a force between the core 30 and the slug 34. Rather, since the slug 34 is substantially made from pre-compacted metal powder, the material of the slug 34 shears along the contact surface resulting in a low friction boundary. This effect decouples the deceleration of the core 30 from the slug 34 during target penetration. As a result, the slug 34 retains much of its initial impact velocity while the core 30 decelerates. The slug 34 therefore maintains high kinetic energy which it applies to the target 26.
Because of the low yield stress of the slug material, the slug material behaves in a manner similar to that of an incompressible fluid as it travels down the central cavity 32 defined by the core 30. In particular, the slug material elongates and accelerates to a much higher velocity. Such operation results in very high pressure at the front end 50 causing perforation of the core 30 and hydrodynamic penetration of the target 26. Further details will now be provided with reference to
In step 104, the manufacturer disposes the slug 34 in a central tapered cavity 32 defined by an elongated core 30. The slug 34 occupies a volume which is smaller than a volume of the central cavity 32. In some arrangements, the elongated core 30 is substantially made of tool steel and the central tapered cavity 32 is formed while the tool steel remains hot/softened (e.g., drilled, punched, or otherwise deformed to provide the tapered shape). Once the core 30 has cooled and hardened, the slug 34 is inserted into the back end 52 of the core 30 (also see
In step 106, the manufacturer places an outer jacket 36 around the elongated core 30 to operate as an interface between the formed armor penetrating round 24 and a barrel when the armor penetrating round 24 is later fired through the barrel. Suitable materials for the outer jacket 36 include copper, nickel and steel alloys, and the like.
It should be understood that such use of a high density powdered metal as the slug material results in effective jet 60 formation (also see
As mentioned above, an improved armor penetrating round 24 utilizes a hollow core 30 which contains a slug 34 to achieve penetration effects beyond that of a conventional armor piercing bullet. In particular, in the improved armor penetrating round 24, the slug 34 initially resides at the back of a tapered cavity 32 within the core 30. When the improved armor penetrating round 24 impacts an armored target 26 such as an armor plate, the material of the slug 34 decouples from the back of the tapered cavity 32 within the core 30 and accelerates through the tapered cavity 32 in the direction of the armor plate. As the material of the slug 34 shears against the tapered walls of the core 30 within the cavity 32, the slug material forms a jet 60 which provides further penetration into and perhaps through the armor plate. Accordingly, the armor penetrating round 24 is capable of providing enhanced destructive and/or lethal effects beyond conventional armor piercing bullets.
While various embodiments of the present disclosure have been particularly shown and described, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present disclosure as defined by the appended claims.
For example, it should be understood that the various geometries of the armor penetrating round 24 may be adjusted to achieve certain effects. Along these lines the dimension of the front end 50 of the core 30 may be changes (e.g., shortened, augmented with lead, etc.) to change the center of gravity or counter act the presence of the slug 34 and the cavity 32. Additionally, the geometries may be modified to increase core performance (i.e., core penetration into the target 26) over nozzle performance (i.e., jetting).
Additionally, it should be understood that, in some arrangements, the slug material is pre-compacted over a relatively high percentage of the crystalline density of the underlying metal such as 60%. It should be further understood that pre-compaction of less than 60% may be appropriate, e.g., for certain effects or in certain situations.
Furthermore, it should be understood that a variety of geometries are suitable for the front end of the cavity 32. For example, in some arrangements, the front end of the cavity 32 has a non-zero radius (see
