Non-lethal ammunition for a riot gun assembles a bi-chambered projectile body and an impact nose, the assembly being spin-stabilized and nose-heavy such that the nose will impact first at the target. The rearward end of the assembly is mounted into the forward end of a shell casing having a high-energy gas expansion chamber, the mounting forming a low-pressure chamber at the rearward end of the projectile. A cup-shaped multi-port gas diffuser plug, spaced from the projectile body, directs burnt propellant gases from the expansion chamber into the low-pressure chamber to expel the projectile at a relatively low velocity. A sleeve interiorly of the gas diffuser plug closes the ports and is degraded by the burnt gases to provide a complete burning of the propellant.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to the field of non-lethal/less lethal ammunition wherein a projectile, such as used in riot control, is fired from the barrel of a held grenade launcher and, respectively, shatters to release a dye or gas and/or remains intact upon impact, respectively, to produce trauma. More specifically, the invention relates to such ammunition having a high/low gas propulsion system wherein high-energy propellant gases are created in a small high pressure chamber, efficiently burned, and the high pressure instantaneously released into a larger volume to expel the projectile from a cartridge and the barrel of a gun at a controlled relatively low exit velocity, and a projectile having a configuration such that the nose thereof will hit a specifically identified target upon impact.

2. Description of the Prior Art

Non-lethal or less lethal ammunition provides friendly forces with the capability to stop, confuse, disorient, or momentarily deter a potential threat without using deadly force. Military forces and local police units use non-lethal ammunition to apply the minimum force necessary while performing functions of crowd control and site area security. In particular, the non-lethal/less lethal ammunition is intended to be a direct fire, low hazard, non-shrapnel producing device that statistically will produce less lethal trauma upon impact and a low probability of death upon impact.

Typically, the less-lethal ammunition includes a large caliber metallic cartridge case that fits into the chamber of the launcher, a smooth or rifled barrel, a projectile, a smaller caliber propelling charge, such as a .38 or .44 that houses a percussion cap, and a propellant to expel the projectile. The large caliber cartridge case is in the form of a cylindrical shell casing with the forward end portion receiving the projectile and the rearward end portion receiving the smaller caliber cartridge propelling charge case inclusive of propellant and percussion cap. In use, the cap is struck by a firing pin, the propellant ignited, and the efficient burning of the propellant in a confined area generates a pressurized gas that instantaneously releases its pressure into the larger cartridge case and forces the projectile out of the forward end portion of the large caliber cartridge casing and then, typically, through the bore of a smooth or rifled barrel.

The propellant is oftentimes in the form of gunpowder that fills the small caliber shell casing of a conventional pistol cartridge, such as a commercially available .38 or .44 caliber cartridge. The powder in the shell when ignited provides a high energy burst of gas that expels the projectile from the large caliber cartridge and at a high velocity. The hi-lo system, as described in the previous paragraph differs in operational concept to the system described herein. Riot control ammunition and less lethal ammunition is considered to be non-lethal or less lethal if the projectile velocity is low and usually lethal if the projectile velocity is high.

U.S. Pat. No. 5,086,703 (issued Feb. 11, 1992) to Klein discloses a non-lethal riot control cartridge wherein the intention is to accelerate a relatively large mass (relative to the amount of propellant involved) to a relatively low velocity, which Patent is specifically incorporated herein by reference.

In Klein, a large caliber such as a 37 mm or 40 mm metal cartridge contains and seats a small propelling charge such as a .38 or .44 caliber inside a chamber formed at the rearward end of a bi-chambered projectile. When the percussion cap in the cartridge is fired, high-pressure propellant gases fill the projectile chamber and force the projectile forwardly with respect to the cartridge. Upon reaching and moving forward of the propelling charge, the high pressure gas is released into the larger volume of the 37 mm or 40 mm cartridge case, forcing the projectile through the barrel of a grenade-launching weapon. The result is the creation of a high-pressure chamber within the metallic cartridge and the base of the projectile and a low-pressure chamber within the larger 37 mm or 40 mm cartridge case located in the space behind the projectile as the projectile moves forward, clearing the expulsion end of the .38 or .44 cartridge case to exit the weapon. Such a system is often referred to as a “Hi/Low” gas delivery system.

Depending on the application, discharge velocity, or to control trajectory and distance, the bore of the gun barrel or tube may be rifled or smooth. The rifling provides spin-control and promotes dynamic stability to ensure that that nose of the projectile will impact at a selected target. Further, careful consideration of projectile geometry, payload and the like may also contribute to ensuring that a target aimed at will be reached and the payload expelled.

U.S. Pat. No. 7,086,337 (issued Aug. 8, 2006) to Klein discloses non-lethal ammunition for a riot gun which includes a forwardly open casing, a projectile mountable in and dischargeable from the casing, a propellant cartridge extending into the casing interior, and a UV curable adhesive disposed in sealing relation about the propellant to effectuate uniform firing of the projectile. The projectile includes rearward and forward end portions each provided with a central cavity with the rearward cavity enclosing the cartridge, a weight in the forward cavity for balancing and increasing the mass of the projectile, and a subassembly carrying in a nose thereof a chemical payload or chemical agent, the subassembly including a stem sized for interference fitment within the forward cavity to secure the subassembly to the projectile and having a chamber for positioning the weight in the forward cavity

Although many of the known riot control systems are believed suitable for the uses intended, there is an ongoing need for improvements in such ordnance.

An object of this invention is the provision of high-low pressure non-lethal/less lethal ammunition that uses the high pressure provided by ignition of a conventional explosive, such as from firing a standard .38 or .44 cartridge case, to create a high-pressure gas to provide a predictable and reliable quantity of low-pressure gas to propel a projectile, fitted to the cartridge, away from its fitment at a relatively low but predetermined velocity.

Another object of this invention is the provision of non-lethal/less lethal ammunition having a gas delivery system that will effectively control and transform the high-energy burst of the propellant from a high velocity to a low velocity.

Another object of this invention is provision of a gas delivery system in non-lethal/less lethal ammunition that will direct and diffuse the energy of propellant gases from a high-pressure expansion chamber into a low-pressure chamber to propel the projectile from the cartridge and weapon at a low velocity.

Another object of this invention is provision of non-lethal/less lethal ammunition having a removable and reloadable high-pressure chamber.

Another object of this invention is provision of non-lethal/less lethal ammunition having a reloadable cartridge system, including a reloadable delay sleeve that controls the burning and replaced for the next use of the cartridge, that is cost effective and saves costs in training.

Another object of this invention is provision of non-lethal/less-lethal ammunition having a reloadable propelling charge that consists of a modified conventional .38 or .44 cartridge case, primer and propellant which is the power source for firing and replaced for the next use of the cartridge, that is cost effective and saves costs in training.

Another object of this invention is provision of non-lethal/less lethal ammunition having a projectile that is configured to fly, and impact, nose first, while describing a predetermined ballistic trajectory.

Another object of this invention is provision of non-lethal/less lethal ammunition wherein the balance and/or weight of the projectile may be changed simply such as by varying the thickness of the walls or base and/or making the walls or base thinner or thicker.

Another object of this invention is the provision of a spin-stabilized projectile that does not shatter upon impact, and carries an aerodynamic shaped nose (or payload) comprised of a material that does not shatter upon impact, but bounces or expands, or a material having a payload chamber for carrying a tear gas and other non-lethal chemicals that shatters and the chemicals dispersed upon impact.

Another object of this invention is the provision of a projectile configured such that the mass center, or center of gravity, of the projectile is located proximate the nose at the forward end of the projectile so as to maintain the nose in position for impact.

Another object of this invention is the provision of spin-stabilized combination of grenade launching tube and expellable projectile, the projectile being generally cylindrical, bi-chambered, and provided with an exterior driving band, or obturating rib, in encircling relation with an interior bulkhead that divides the projectile into two interior chambers, the driving band cooperating with the interior wall of the launching tube to control spin of the projectile when propelled therefrom.

It would be desirable, and is an object of this invention, to provide non-lethal riot gun ammunition that has the desired accuracy and which employs a projectile which is usable for different types of applications (i.e. a barricade penetrating tear gas head, UV, dust dispersal, trauma inducing etc.), thus improving upon manufacturing techniques and reducing costs.

As subsequently detailed, the present invention is directed to and achieves the above desired objects.

SUMMARY OF THE INVENTION

The instant invention provides a non-lethal/less lethal ammunition comprising: a bi-chambered projectile and a cup-shaped shell casing, the projectile being releasably mounted at a rearward end to the casing and closed at a forward end by a nose, and configured such that the center of gravity of the assembly (projectile and nose) is towards the forward end of the assembly whereby the nose will impact upon reaching a target, the casing including a gas supply arrangement wherein a gas diffuser plug consisting of a removable and reloadable high pressure chamber and a degradable delay sleeve are arranged to radially discharge uniformly burnt propellant gases at high energy and reduce the gases to a lower pressure, wherein degradation of the delay sleeve materials controls the rate of discharge and ensures that complete uniform burning takes place, and wherein the low pressure gases engage a cup-shaped chamber at the rearward end of the projectile body wherein to propel the projectile assembly from the casing at a low velocity.

The invention provides non-lethal/less lethal ammunition for use in a riot control firearms such as 37 mm and 40 mm firearms/launchers.

The invention provides non-lethal/less lethal ammunition wherein a projectile body permits a desired payload to be loaded for a desired circumstance by merely choosing the correct nose configuration.

According to this invention, in a first preferred embodiment thereof, non-lethal/less lethal ammunition for the controlled delivery of a projectile to a target, comprises:

a cup-shaped casing, said casing including a high-pressure expansion chamber to receive an explosive propellant;

a cylindrical projectile, said projectile being expellably mounted in said casing and comprised of a non-rupturable material adapted to remain intact and not burst into pieces following a violent impact, said projectile including, respectively, rearward and forward end portions, said rearward end portion and said casing cooperating to form a low pressure chamber when the projectile is mounted to the casing;

an impact nose secured to the forward end portion of said projectile; and

a gas diffuser system for receiving high energy propellant gases from the expansion chamber and delivering the high pressure of the same into the low pressure chamber formed by the 37 mm/40 mm cartridge case following substantially complete and uniform burning of the propellant, said diffuser system being axially spaced from said projectile.

According to this preferred embodiment, the removable and reloadable high-pressure gas diffuser system comprises:

a gas diffuser plug, said plug including a cup-shaped body having a hollow interior, and a replaceable delay sleeve of degradable material, said cup-shaped body including a sidewall having an interior surface, a closed upper end, an open lower end, and at least one gas outlet port in said sidewall, and said delay sleeve being disposed in said hollow interior and in facing and closing relation, respectively, with and against said interior surface and said gas outlet port; and

means for connecting the gas diffuser plug to said casing, said means for connecting placing the expansion chamber in fluid communication with the hollow interior of said gas diffuser plug and orienting the outlet port for directing propellant gases in a direction transverse to the expelling direction;

wherein uniformly burnt high energy propellant gas from the expansion chamber is first directed in a first direction generally along the geometric axis of the projectile and said casing, then in a second direction generally transverse to the geometric axis by degrading the material of the delay sleeve to pass through the outlet port or ports and into the low pressure chamber, and then in the first direction to be received in the first chamber and expel the projectile from the casing.

The sidewall of the gas diffuser plug is generally cylindrical. To adequately distribute the gases, the plug sidewall preferably includes a plurality of gas outlet ports. In one application, the gas diffuser plug includes four gas outlet ports arranged generally equiangularly about the sidewall and adapted to direct the burnt gases radially relative to the geometrical axis of the gas diffuser plug.

The replaceable delay sleeve is preferably comprised of a suitable material that will degrade, over time, when exposed to the high pressure and temperature of burnt propellant gases, to control and enable complete and uniform burning of the propellant.

The rearward end of the projectile body forms a cup-shaped chamber that is generally symmetrically centered along the geometric axis of the projectile, and formed by a generally cylindrical or annular surface, and a continuous planar surface that is transverse to the axis of the projectile. The burnt propellant gases from the diffuser plug are delivered into the low-pressure chamber and generally uniformly distributed across the planar surface to expel the projectile outwardly of the casing at a predetermined relatively low velocity.

The center of mass of the assembly of the projectile body, payload, and nose is proximate the forward end of the projectile assembly, wherein the projectile assembly will fly oriented with the impact nose first while describing a ballistic trajectory.

The nose is removably fitted into the forward end portion of the projectile body, thus enabling differently configured noses and payloads carried thereby to be replaced in a projectile body and expelling casing

Preferably, the nose is comprised of non-rupturable and rupturable materials or component parts. In one application, the nose is comprised of non-rupturable elastomeric material, and is a “bouncer”, and the projectile body is comprised of a polymeric material that does not shatter or break apart upon impact, such as nylon. In other applications, the nose carries a chemical to be dispersed and shatters upon impact.

Further, in some applications, the delay sleeve may be comprised of a thin metallic or plastic sleeve, which sleeve will degrade when the sleeve interacts with the burnt high energy propellant gases.

In another preferred embodiment, there is provided according to this invention non-lethal/less lethal ammunition adapted to launch a projectile from a tube, comprising:

a cup-shaped shell casing having a primer end and a payload expelling end, said primer end including a high energy expansion chamber for burning propellant gases and a cup-shaped gas diffuser plug for the controlled delivery of said burnt gases, said gas diffuser plug including an interior cavity for receiving burnt gases from said expansion chamber, at least one outlet port for radially discharging burnt propellant gases from said interior cavity, and a replaceable delay sleeve of degradable material, said delay sleeve being disposed in closing relation with said outlet port and of a material adapted to substantially simultaneously permit the propellant to burn completely and the sleeve material to degrade whereby to expose the outlet port and permit burnt propellant gases to pass through the outlet port;

a generally cylindrical bi-chambered projectile body of non-rupturable material expellably mounted in the expelling end of said shell casing, said projectile body including a rearward end portion mounted to the expelling end and in spaced relation to the gas diffuser plug, a forward end portion remote to the casing, a bulkhead dividing the interior of the projectile body into first and second chambers, and an exterior driving band to cooperate with the interior wall of the launching tube to spin-stabilize the projectile when launched, said first chamber being disposed in said rearward end portion, shallow, generally cup-shaped, and in juxtaposed spaced relation to said gas diffuser plug to form, with said casing, a low pressure chamber for receiving and distributing burnt propellant gases across the bulkhead, and said second chamber being disposed in said forward end portion;

a nose removably mounted in said second chamber;

wherein an assembly of said projectile body and said nose has a center of mass proximate to the forward end of the projectile body to enable the projectile to fly and impact nose first while describing a desired ballistic trajectory.

The nose may be solid and of non-rupturable material. Further, the nose may be multipart, include an interior chamber for carrying a payload, and be comprised of a rupturable material that breaks apart to disperse the payload upon impact. The nose includes a body portion dimensioned for fitment into the second chamber and in closing relation therewith, a forward impact head, and a payload for carrying teargas and the like, and which will deploy or otherwise scatter upon impact.

The non-lethal/less-lethal ammunition further comprises a gunpowder charge in the expansion chamber, and a percussion cap for exploding said gunpowder charge.

According to an aspect of this invention, there is provided a cartridge for the controlled delivery of a fluid comprising:

a cup-shaped shell casing, having a closed lower end, an open upper end, and a continuous vertical cylindrical side wall thereby defining a hollow interior;

a high energy expansion chamber provided in said lower end;

an explosive propellant charge in said expansion chamber;

a percussion cap in operable relation with said charge to explode the propellant; and

a cup-shaped gas diffuser plug, having an open lower end, a closed upper end, and a continuous vertical cylindrical wall thereby defining a hollow interior cavity, the upper end portion of said cylindrical wall including a plurality of generally equiangularly spaced outlet ports for passing burnt gases radially from the interior cavity to the hollow interior, and a replaceable delay sleeve of degradable material disposed in said interior cavity and in closing relation with the outlet ports, communication of burnt gases into said interior cavity causing the material of the sleeve to degrade, over time, and be removed from closing relation with the outlet ports.

According to this invention, a brass or aluminum .38 or .44 caliber cartridge insert, which holds the propellant and primer, is pressed into a bore formed in the base of the shell casing.

The launching weapon firing pin strikes the primer igniting the propellant or gun powder inside the propelling charge. The burning propelling charge located partially inside the gas diffuser plug lined with the delay sleeve generates sufficient pressure and heat to burn through the delay sleeve to release the expanding propellant gases through the outlet port and into the low-pressure chamber. The rotating driving or obturating band around the projectile body engages rifling in the launcher tube and imparts a spin to the projectile. The pressure, created by the expanding gases in the low-pressure chamber, forces the projectile through the launching tube.

In a typical example, the spin imparted to the assembly of the projectile and impact nose is in the order of 2,000 plus rpm, and the discharge velocity of about 237 feet per second. Upon impact, depending on the nose, the nose bounces, expands, or shatters, causing the chemical payload to disperse, to incapacitate without causing a fatality. In no condition does the projectile casing ever shatter or rupture, such as by the nose impact forces being transmitted thereto.

The delay sleeve, propelling charge, and the nose are changeable to accommodate the type of ammunition desired.

The various features, advantages and other uses of the present invention will become more apparent by referring to the following description and drawings.

Throughout the following description and drawing, identical reference numbers refer to the same component shown in multiple figures of the drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to the drawings, and in particular toFIGS. 1 and 5, preferred embodiments of non-lethal projectile ammunition according to the present invention are shown. Each is similar but differs in the payload utilized. In the ammunition shown inFIG. 1, the nose of the ammunition is solid, whereas inFIG. 5, the nose carries a payload, such as tear gas, as will be described in greater detail herein below. As will be described, each projectile ammunition is of the non-lethal or less lethal type and includes a removable and replaceable high-low propulsion system wherein high-pressure propellant gases in a pressure expansion chamber of the casing is diffused and delivered to a low-pressure chamber formed between the rearward end of the projectile body when expellably mounted to the casing.

The ammunition maintains strict compliance with the caliber or size requirement of the weapon or firearm (not shown) used to fire the ammunition. Illustrative of an application using the non-lethal ammunition herein is the M203 breech loading grenade launcher with rifled barrel that attaches to the M16 assault rifle or the M4 carbine and designed for a single shot 40 mm grenade. Typically, the M203 launches grenade ammunition through a 40 mm bore with a muzzle velocity of about 250 feet per second (76 m/s), to have an effective range as needed, depending on the application. In some applications, a smooth barreled weapon may be used.

Referring toFIGS. 1 and 2, the non-lethal ammunition according to this invention is generally denoted by the reference number10. The projectile ammunition10includes a shell casing12, a projectile body14, and an impact nose16. The nose16is solid, not designed to rupture, formed into one-piece, of non-rupturable material or comprised of non-rupturable components, and comprises the payload.

The casing12is of a suitable metal, such as aluminum or the like, generally cup-shaped and includes a cylindrical sidewall20closed at a lower end by an end wall22and forms an interior chamber24leading to a payload expelling opening26(seeFIG. 1) at the forward end. The end wall22includes an exterior end face28and a cylindrical bore30extends between the end face28and interior chamber24. A cartridge case insert32, which holds a propellant, such as gunpowder, and includes a primer or percussion cap, is pressed into the bore. Preferably, the propelling charge is loaded with smokeless gunpowder. The bore30forms a high-pressure expansion chamber to contain burnt propellant gases of the insert when the percussion cap is struck by the weapon pin.

Typically, the casing12is a readily available 40 mm cartridge case of aluminum.

The projectile14is in the form of a generally cylindrical shell or body34having rearward and forward end portions34aand34band an interior wall or bulkhead36which divides the interior of the projectile body34to form rearward and forward chambers38and40, respectively, in the rearward and forward end portions34aand34b. The rearward chamber38is generally cup-shaped and includes a cylindrical or annular wall38aand a flat generally planar circular wall38b. The rearward facing surface38bof the bulkhead36is disposed in a plane generally perpendicular to a geometrical axis “A” passing through the projectile body34and shell casing12when the projectile14is expellably assembled to the casing12. The rearward chamber38of the projectile in combination with the interior chamber24of the shell casing12forms a low-pressure chamber into which the high-energy expansion gases are directed. The expansion gases distribute generally uniformly across the flat surface38bto promote controlled expulsion.

The forward chamber40is elongated, generally cylindrical, longitudinally extending, and outwardly open to receive the impact nose16.

An obturating or driving band42, generally at the location of the bulkhead36, extends around the exterior of the projectile body34and is dimensioned to form a snug closure with the interior wall “W” (seeFIG. 1) of the launch tube “T” to assist in spin-control.

A pair of grooves44and associated ribs46are formed around the exterior of the rearward end portion34ato assist in controlled retention in the shell casing12and control spin during expulsion of the projectile body34from the casing12. Additionally, the grooves44and ribs46cooperate in preventing, or at least reduce the energy of, burnt high-energy propellant gases passing between the fitment interface formed by the projectile body34and the sidewall20of the shell casing12. In this regard, one or both of the grooves are fitted with an O-ring seal41.

Preferably and according to this invention, the projectile body34is comprised of a material that is resistant to rupture or shattering. It is important that the material of the projectile body does not suddenly break or burst into pieces upon application of a violent impact or blow thereto, such as resulting from impact of the nose16against a destination target.

According to this invention, a suitable material is an acetyl homopolymer, such as Delrin®. These polymers have high tensile strength, impact resistance and stiffness, outstanding fatigue endurance, and resistance to many chemicals. Further, these polymers offer dimensional stability and maintain natural lubricity at a wide end-use temperature range.

The nose16is generally cylindrical and includes a shaped head48, and a body member50, each arranged on a common axis, which axis is aligned with the geometric axis “A” when the nose16is assembled to the forward end portion of the projectile body34. The shaped head48includes a cylindrical exterior surface48a, a flat end face48badapted to face forwardly, and a flat end face48cadapted to face rearwardly and seat against the forward end34dof the projectile body34. A rounded transition surface connects the exterior surface48ato the end face48bto improve the flight ballistics when the projectile moves through the air.

The body member50extends coaxially rearwardly from the end face48cof the head48and includes a cylindrical exterior surface50aand an end face50b. The exterior surface50aand end face50b, at least in part, define a series of locking tabs which act against the surface34cof the projectile body34and provide a snug gripping engagement therewith to permit the impact nose16to be removably mounted to the projectile14and form an end closure to the forward chamber40.

The nose16is designed not to rupture. The nose16is formed into a one-piece component and from a material selected that is not rupturable. While many materials are contemplated, preferably the nose is comprised of nylon, a polyurethane elastomer, or a combination of both.

In another embodiment according to this invention, as shown inFIG. 5and discussed hereinbelow, a like-shaped nose116is comprised of a rupturable material, or components that enable the nose116to rupture.

According to an important feature of this invention, a gas delivery or diffuser system is provided wherein a gas diffuser plug54is placed in fluid communication with the expansion chamber30to receive burnt high-energy propellant gas from the expansion chamber30, reduce the pressure, and direct the burnt propellant gases into a low-pressure chamber, formed by the combined chambers24and38formed behind the rearward end of the projectile body34, when the projectile14is expellably mounted to the shell casing12.

As shown inFIG. 3, the gas diffuser plug54is generally cup-shaped having a cylindrical sidewall54aand a flat closure head54b, and forms an interior cavity54cadapted to receive the burnt high-energy propellant gases.

While many materials are suitable, preferably the gas diffuser plug54is of a metal that resists degradation by burnt gases, such as steel or stainless steel. Preferably, the shell casing12is of brass or aluminum.

At least one vent hole or gas outlet port54dis provided in the sidewall54ato pass the burnt propellant gases from the bore30into the casing interior24. Preferably, a plurality of gas outlet ports of suitable diameter and shape are provided to ensure uniform distribution of burnt propellant gases. In the embodiment illustrated, four outlet ports54dare provided, each generally circular in shape, disposed equiangularly, and adapted to pass the burnt gases radially (i.e., in a direction transverse to the expelling direction).

Matching thread60is provided on the exterior sidewall54aof the plug54and on the interior wall of the bore30to enable the gas diffuser plug to be removably mounted to the shell casing12. To enable rapid replacement or permit cleaning and recharging of the shell casing for reuse, the top surface of the closure head54bis provided with a slot54eadapted to be engaged by a conventional tool, such as a screwdriver.

Further, and important to the invention herein, a replaceable delay sleeve56of degradable material is fitted into the high pressure interior cavity or chamber54c, against the interior surface54fof the sidewall54a, and in closing relation with the vent hole or outlet port54d. The delay sleeve56is of material adapted to degrade by the action of the burnt high-energy propellant gases directed thereagainst and of a thickness calculated such that the propellant in the shell casing12will completely burn substantially simultaneously with the degrading of the sleeve material, whereby the ports54dbecome open (i.e., exposed) and the gases expelled into the low-pressure chamber, comprised of chambers24and38.

The delay sleeve56may be comprised of a polymeric material, such as nylon, polyurethane, or a polypropylene, or a metal, such as brass or aluminum.

When the projectile14and shell casing12are assembled, a low-pressure chamber24and38is formed behind the projectile body34. In such assembly, the forward end54bof the gas diffuser plug54is spaced axially rearwardly and away from the rearward end34eof the projectile14. The cup-shaped rearward chamber38of the projectile14is coaxially juxtaposed above and about the top54bof the gas diffuser plug54.

The assembly of the projectile14and the nose16is nose heavy, such that the projectile assembly will fly and impact nose first while describing a desired ballistic trajectory. That is, the mass center, or center of gravity of the projectile assembly, is forwardly and proximate to the head48of the nose16and the projectile assembly will not tumble in flight. In general, in the embodiment shown, the mass center is located proximate to the interface between the end face48cof the nose head48and the front end face34dof the projectile body34, against which the nose head48seats.

According to this invention, the nose may also be configured to carry a special payload, in the form of a scatterable or dispersible substance, such as tear gas, dye, UV fluids, or other non-lethal material.

Referring toFIG. 5, the non-lethal ammunition is as described above, and the nose, generally indicated by the reference number116, is substantially on the exterior identical to the nose shown and described herein above. According to this embodiment, the nose116is generally cylindrical and includes a shaped head148and a body member150, the head fitted to the body to form a unit having substantially the same size and shape as the nose16. When assembled together, the head and body148and150are coaxially arranged on a common axis, which axis is aligned with the geometric axis “A” when the nose116is assembled to the forward end portion of the projectile body34.

The shaped head148is cup-shaped and includes an interior chamber149. The head148includes exterior and interior surfaces148aand148b, respectively, a flat forward end face148cadapted to face forwardly, and a flat end face148dadapted to face rearwardly and seat against the forward end34dof the projectile body34. A rounded transition surface connects the exterior surface148ato the forward end face148bto improve the flight ballistics when the projectile moves through the air.

The body member150includes an annular collar151, which includes a rearwardly facing support surface151aand exterior cylindrical surface151b. The support surface151aseats upon the forward end34dof the projectile body34. The exterior cylindrical surface151bis dimensioned to be fitted within the chamber149and engage the interior surface148bof the chamber149.

The nose116, when assembled, is adapted to be removably mounted to the projectile14and form an end closure to the forward chamber40, much as shown and described as regards the one-piece nose16herein above. Further, the nose116is formed of a rupturable material.

A dispersible medium, such as an inert powder or tear gas, shown by the reference numeral153, or like material that scatters upon bursting impact of the nose, is provided in the chamber149when the head and body members148and150are united. For clarity, a portion of the material153is cut-away to show the interior cup-shaped chamber149formed within the nose116.

In order to fire the ammunition10, in operation, the projectile14and the nose16, or116, are preassembled. The rearward end34aof the projectile assembly is loaded into the chamber24of the shell casing12, which casing is preloaded with the propellant or propelling charge, and which propellant insert seals the expansion chamber30and the bottom of the casing12. The shell casing and projectile assembly are loaded into the grenade launcher for firing.

Upon firing, turning toFIG. 4, the propellant is exploded in the high-energy expansion chamber30, burnt high-energy propellant gases fill the interior cavity54c, the delay sleeve56is degraded and the vent holes54dopened, and the burnt gases radially diffused into the low-pressure chamber24and38behind the projectile14. The gases enter the cup-shaped chamber38and uniformly distribute against the annular wall38a, whereupon the projectile assembly is issued from the casing.

It is to be, thus, appreciated by interchangeability of the nose, payload, and projectile body, the type of ammunition defined by the projectile can be altered and the cost of manufacture greatly reduced.

Additionally, the gas diffuser plug54does not have to be discarded after use. The delay sleeve56, although burnt by the explosion gases, may simply be replaced with a new delay sleeve. Further, the material selected for the delay sleeve enables the user to control the burn time before the gases are converted from high to low velocity expulsion.