Techniques utilizing high performance armor penetrating round

An armor penetrating round 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.

BACKGROUND

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.

SUMMARY

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.

DETAILED DESCRIPTION

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 .50 caliber armor piercing bullet).

FIG. 1shows a situation20in which a firing device22fires a high performance armor penetrating round24at a target26. Various apparatus are suitable for use as the firing device22such as a gun, a cannon, or similar type of projectile launcher.

Each high performance armor penetrating round24includes an elongated core30which defines a cavity32which narrows (or tapers) from back to front, a slug34which is disposed within the cavity32, and an outer jacket36. As will be explained in further detail shortly, when such a round24is fired from the firing device22in a forward direction F (see arrow F inFIG. 1) and impacts the target26, the material of the slug34accelerates through the cavity32in the forward direction F to causing further destructive effects.

As shown by the arrow L inFIG. 1, the armor penetrating rounds24are loaded into the firing device22in the form of ammunition40. Each round of ammunition40may be loaded individually or manually, e.g., hand loaded by a user. Alternatively, the firing device22may receive rounds of ammunition40automatically a faster rate and in a less burdensome manner than that of hand loading, e.g., from an ammunition belt or a magazine, etc.

Each round of ammunition40includes a shell42, propellant44which is loaded within the shell42, and an armor penetrating round24. When a round of ammunition40is loaded within the firing device22and fired, the propellant44within that ammunition round40ignites and propels the armor penetrating round24from the shell42and through the barrel of the firing device22toward the target26. As will now be explained in further detail with reference toFIGS. 2-4, the armor penetrating round24is constructed and arranged to provide enhanced destructive and lethal effects upon impact with the target26.

FIGS. 2-4show the armor penetrating round24at various times during impact with the target26. By way of example only, the target26inFIGS. 2-4is a 1.5 inch thick RHA plate and the armor penetrating round24is a .50 caliber round having a muzzle velocity of 853 meters per second shot at the target26from 100 yards away.FIG. 2shows a cross-section of the armor penetrating round24at the point of impact.FIG. 3shows a cross-section of the armor penetrating round24after the core30has penetrated into the target26, but prior to release of slug material from the core30.FIG. 4shows a cross-section of the armor penetrating round24when the slug material forms a jet which further penetrates into and ultimately through the target26.

As illustrated inFIG. 2, the core30is elongated and defines a front end50(i.e., the leading part of the core30which hits the target26first), an aft end52(i.e., the trailing part of the core30), and the cavity32which has a tapered shape. The cavity32extends along a central axis54. As shown by the cross-section, an aft cross-sectional diameter of the cavity32adjacent the aft end52is larger than a front cross-sectional diameter of the cavity32adjacent the front end50.

As further shown inFIG. 2, the slug34is disposed initially within the cavity32at the aft end52. It should be understood that the slug34includes material which has a low yield strength and which is capable of forming a jet to perforate the front end50of the core30(FIGS. 3 and 4). To initially form the slug34, the slug material may be pre-compacted and perhaps mixed with an epoxy or binder to hold the slug34together (FIG. 2). Examples of material which is suitable for forming the slug34include powdered metal such as lead powder, titanium powder, tantalum powder, and the like. In some arrangements, the slug34may further include a pyroforic material to enhance lethality.

It should be understood that the slug34does not fully fill the cavity32of the core30. Rather, there is space in front of the slug34(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 slug34has a depth D1as measured along the central axis54and the cavity32has a depth D2as measured along the central axis54, where D2is in the range of 3 to 4 times D1. For example, in certain arrangements, the slug34is substantially 1 cm thick (i.e., D1=1 cm) and the cavity32is 3 to 4 cm's thick (i.e., D2=3 to 4 cm).

It should be further understood that the composition of the slug34and the tapered shape of the cavity32are such that, upon impact of the armor penetrating round24with the target26, the slug34easily decouples from the aft end52of the core30and disintegrates due to shearing along the inner core walls within the cavity32as the slug material proceeds in the forward direction F through the cavity32as shown inFIG. 3(i.e., the core walls become a de facto low friction boundary which pressurizes and accelerates the slug material as the slug material moves forward in accordance with Bernoulli's principle). That is, when the core30impacts the target26, the core30immediately decelerates but the slug34retains much of the initial impact velocity. Accordingly, the slug material rushes in the forward direction R to form a jet (i.e., a stream having incompressible fluid properties due to the low yield strength of the material) which accelerates in the forward direction F to perforate a front tip of the core30(seeFIG. 3) and further penetrate the target26. With the slug material maintaining high kinetic energy, the slug material is capable of applying that energy to penetrate deeper into the target26and perhaps reach further target components.

In some arrangements, the geometry of the cavity32and the composition of the slug34are such that the material of the slug34is able to accelerate to at least 2 times (2×) that of the armor penetrating round24at 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 slug34.

As shown inFIG. 4, the accelerated slug material forms a jet60which perforates the front end50of the core30and is capable of further penetrating into and perhaps through the target26depending on target depth. For example, if the jet60is able to fully penetrate an outer target barrier as shown inFIG. 4, the escaping jet60is then able to reach and effect other target components in its path.

One should appreciate that several physical effects combine to provide the high performance aspects of the armor penetrating round24. For example, the material of the slug34has very low yield strength. Additionally, the friction between the slug34and the inner walls of the core30does not significantly transfer a force between the core30and the slug34. Rather, since the slug34is substantially made from pre-compacted metal powder, the material of the slug34shears along the contact surface resulting in a low friction boundary. This effect decouples the deceleration of the core30from the slug34during target penetration. As a result, the slug34retains much of its initial impact velocity while the core30decelerates. The slug34therefore maintains high kinetic energy which it applies to the target26.

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 cavity32defined by the core30. In particular, the slug material elongates and accelerates to a much higher velocity. Such operation results in very high pressure at the front end50causing perforation of the core30and hydrodynamic penetration of the target26. Further details will now be provided with reference toFIG. 5.

FIG. 5shows a flowchart of a procedure100for making a high performance armor penetrating round24. In step102, a manufacturer compacts powdered material to form a slug34. In some arrangements, the powdered material includes powdered metal, pyroforic material, epoxy, combinations thereof, etc. Suitable powdered metals include lead powder, tungsten powder, tantalum powder, and similar powders which provide very low yield strength.

In step104, the manufacturer disposes the slug34in a central tapered cavity32defined by an elongated core30. The slug34occupies a volume which is smaller than a volume of the central cavity32. In some arrangements, the elongated core30is substantially made of tool steel and the central tapered cavity32is formed while the tool steel remains hot/softened (e.g., drilled, punched, or otherwise deformed to provide the tapered shape). Once the core30has cooled and hardened, the slug34is inserted into the back end52of the core30(also seeFIG. 2).

In step106, the manufacturer places an outer jacket36around the elongated core30to operate as an interface between the formed armor penetrating round24and a barrel when the armor penetrating round24is later fired through the barrel. Suitable materials for the outer jacket36include 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 jet60formation (also seeFIG. 4). Such material is suitable since the material has essentially zero yield stress and does not significantly resist deformation and jetting. Moreover, the initially density of the powdered material within the slug34can be made fairly high by pre-compacting the powdered material yet keeping the effective strength low. In some arrangements, the slug material is pre-compacted over a relatively high percentage (e.g., 55%, 60%, etc.) of the crystalline density of the underlying metal (step102). Accordingly, during the jet formation process, the high pressure near the throat (FIG. 4), the powdered metal achieves a density approaching the crystalline density of the underlying metal. As a result, the jet60essentially has the full density of the metal (e.g., tungsten, tantalum, etc.) thereby penetrating the target26very efficiently.

As mentioned above, an improved armor penetrating round24utilizes a hollow core30which contains a slug34to achieve penetration effects beyond that of a conventional armor piercing bullet. In particular, in the improved armor penetrating round24, the slug34initially resides at the back of a tapered cavity32within the core30. When the improved armor penetrating round24impacts an armored target26such as an armor plate, the material of the slug34decouples from the back of the tapered cavity32within the core30and accelerates through the tapered cavity32in the direction of the armor plate. As the material of the slug34shears against the tapered walls of the core30within the cavity32, the slug material forms a jet60which provides further penetration into and perhaps through the armor plate. Accordingly, the armor penetrating round24is capable of providing enhanced destructive and/or lethal effects beyond conventional armor piercing bullets.

For example, it should be understood that the various geometries of the armor penetrating round24may be adjusted to achieve certain effects. Along these lines the dimension of the front end50of the core30may be changes (e.g., shortened, augmented with lead, etc.) to change the center of gravity or counter act the presence of the slug34and the cavity32. Additionally, the geometries may be modified to increase core performance (i.e., core penetration into the target26) 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 cavity32. For example, in some arrangements, the front end of the cavity32has a non-zero radius (seeFIGS. 2-4). In these non-zero terminus arrangements, the front end of the cavity32may be narrow and almost cylindrical (e.g., produced by drilling a very small diameter hole into the hardened steel core). Such arrangements may facilitate manufacturability and provide satisfactory performance. However, in other arrangements, the front end of the cavity32is substantially conical, ending with essentially zero radius (a sharp point). Other suitable geometries include a rounded front end, a flattened front end, and so on. These different arrangements may be suitable in some situations to purposefully provide different performance results and/or to accommodate various manufacturing techniques. Such modifications and enhancements are intended to belong to various embodiments of this disclosure.