Multiple projectile fixed cartridge

A multiple projectile fixed cartridge includes a casing, a retention insert arranged in the casing, and a plurality of projectiles arranged proximate the retention insert. The retention insert is configured to align and support at least a first projectile of the plurality of projectiles, and the casing is configured to align and support a second projectile of the plurality of projectiles.

BACKGROUND OF THE DISCLOSURE

1.0 Field of the Disclosure

This disclosure relates generally to cartridges for ammunition. In particular, exemplary embodiments are directed to multiple projectile cartridges having an insert arranged within the cartridge casing which includes an interior cavity for supporting one or more projectiles.

2.0 Related Art

Multiple projectile fixed cartridge loads are conventionally referred to as duplex (e.g., two projectiles) or triplex (e.g., three projectiles) loads. Such duplex and triplex loads, when used in a bottleneck casing (e.g., a centerfire rifle casing), can have a plurality of shortcomings. For example, some conventional multi-projectile cartridges have lacked support for one or more projectiles within the casing, which can create problems in maintaining proper projectile alignment, such that accuracy and precision of each of the projectiles may be reduced.

Internalized support structures have been developed for multiple projectile loads generally through the use of recesses formed along a central axis of each projectile. In addition to providing a nested fit between successive rounds, the recesses further may be configured to support a rod, pin, or other alignment device which engages the plurality of projectiles and maintains proper alignment therebetween. However, the use of such tight mating recesses and additional support structures can significantly increase the complexity and cost of manufacture of the projectiles. For example, imperfection in the concentricity or shape of the recesses results in a static and dynamic mass imbalance of individual projectiles. Mass imbalance localized near the rear of a projectile can be particularly harmful to accuracy of the rounds by causing compounding effects on projectile dispersion. Furthermore, due to inherent variations in manufacturing tolerances it is very difficult to form heel cavities or recesses that do not result in some level of mass imbalance.

Assembly of conventional multi-projectile cartridges also can be complicated due to the accuracy necessary in alignment of the multiple projectiles. Oftentimes the projectiles are inserted within a casing as a single unit in a single step, thus requiring substantially precise alignment prior to insertion within the casing. Thereafter, upon firing, presentation of expanding combustion gases to the different projectiles can lead to issues in the accuracy of such projectiles. For example, conventional duplex and triplex loads can lack control in presenting expanding combustion gases to a volume of space between two or more projectiles, thus creating further inaccuracy due to differences in gas pressures acting upon each projectile of the multiple projectiles.

Further complications can arise in the use of multiple projectiles for subsonic loads (e.g., loads presenting a muzzle velocity below the speed of sound). Most conventional weapon systems typically are optimized for the use of supersonic ammunition (e.g., loads presenting a muzzle velocity above the speed of sound). When use of subsonic ammunition is attempted in such weapon systems, malfunctions can occur due to the energy generated by the reduced velocity load being insufficient to reliably cycle the weapon. Typical design changes to counter this deficiency are increasing projectile velocity, increasing propellant mass, and/or increasing projectile mass. Each option has traditionally had substantial shortcomings. Increasing projectile velocity in subsonic loads is by definition constrained. Increasing propellant mass for the same projectile velocity is wasteful/costly. Increasing the mass of a single projectile for any given caliber requires either lengthening the projectile, which typically hinders accuracy due to instability, or constructing the projectile of higher density materials, which usually results in an increased cost.

Accordingly, a need exists for increased accuracy, decreased production costs, and improved weapons functionality in multiple projectile fixed cartridge designs.

SUMMARY OF THE INVENTION

According to an aspect of the disclosure, a multiple projectile fixed cartridge is described. The cartridge includes a casing, a retention insert arranged in the casing, and a plurality of projectiles arranged proximate the retention insert. The retention insert generally is configured to align and support at least a first projectile of the plurality of projectiles, and the casing can be configured to align and support an additional one, e.g., second projectile, of the plurality of projectiles.

According to an aspect of the disclosure, a multiple projectile fixed cartridge is described. The cartridge includes a casing having a primer receiving portion, a projectile receiving portion, and an interior cavity or chamber. The cartridge further includes a retention insert arranged in the interior cavity. The retention insert generally is configured to engage an interior surface of the casing and prevent movement relative thereto. The cartridge further includes a plurality of projectiles arranged within the casing. The retention insert is configured to align and support at least one or more projectiles of the plurality of projectiles, while the casing can be configured to align and support at least one projectile of the plurality of projectiles such that a central axis of the casing, a central axis of the projectile(s) supported by the insert, and a central axis of the at least one projectile supported by the casing are substantially collinear.

According to yet another aspect of the disclosure, a retention insert of a multiple projectile fixed cartridge is described. The retention insert can include a frustoconical portion configured to engage an interior surface of a cartridge casing in a manner so as to substantially restrain longitudinal movement of the retention insert relative to the cartridge casing, a cylindrical portion proximate frustoconical portion, and a cavity formed in the cylindrical portion configured to align and support a plurality of projectiles. The cavity can have a geometry configured to support a portion of an exterior shape of the plurality of projectiles.

Additional features, advantages, and embodiments of the disclosure may be set forth or apparent from consideration of the following detailed description, drawings, and claims. Moreover, it is to be understood that both the foregoing summary of the disclosure and the following detailed description are exemplary and intended to provide further explanation without limiting the scope of the disclosure as claimed.

DETAILED DESCRIPTION OF THE DISCLOSURE

The aspects of the invention and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments and examples that are described and/or illustrated in the accompanying drawings and detailed in the following description. It should be noted that the features illustrated in the drawings are not necessarily drawn to scale, and features of one embodiment may be employed with other embodiments as the skilled artisan would recognize, even if not explicitly stated herein. Descriptions of well-known components and processing techniques may be omitted so as to not unnecessarily obscure the embodiments of the invention. The examples used herein are intended merely to facilitate an understanding of ways in which the invention may be practiced and to further enable those of skill in the art to practice the embodiments of the invention. Accordingly, the examples and embodiments herein should not be construed as limiting the scope of the invention, which is defined solely by the appended claims and applicable law. Moreover, it is noted that like reference numerals represent similar parts throughout the several views of the drawings.

It is understood that the invention is not limited to the particular methodology, devices, apparatus, materials, applications, etc., described herein, as these may vary. It is also to be understood that the terminology used herein is used for the purpose of describing particular embodiments only, and is not intended to limit the scope of the invention. It must be noted that as used herein and in the appended claims, the singular forms “a,” “an,” and “the” include plural reference unless the context clearly dictates otherwise. Unless defined otherwise, all technical and scientific terms used herein have the same meanings as commonly understood by one of ordinary skill in the art to which this invention belongs.

As used herein, a fixed cartridge may refer to a round of ammunition for use in a weapon, where a projectile, propellant, and primer are fixedly arranged in a casing for loading and discharging through the weapon. As used herein, a multiple projectile fixed cartridge may refer to a round of ammunition for use in a weapon, where more than one projectile, one or more propellant(s), and a primer are fixedly arranged in a casing for loading and discharging through the weapon. The more than one projectile may include projectiles of differing weights, compositions, lengths, and/or shapes, or may include projectiles of substantially similar structural composition. The one or more propellant(s) may include at least one charge of a propellant chemistry arranged in the casing and configured to discharge in response to activation by the primer, thereby propelling the more than one projectile through the barrel of the weapon. The multiple projectile fixed cartridge referred to herein may be implemented in many different manners, and such different manners are considered to be within the scope of exemplary embodiments of the present invention and the many drawings presented herein.

Referring to the many drawings,FIGS. 1-8generally illustrate various embodiments of the invention directed to a multiple projectile fixed cartridge including a retention insert arranged in a casing. Generally, the casing may be arranged for use in a plurality of firearms and weapons systems, including, but not limited to, autoloading guns, rifles, shotguns and other long guns, and handguns. The retention insert may be configured to support at least one projectile of a plurality of projectiles, while the casing may be configured to support a second projectile of the plurality of projectiles.

While conventional fixed cartridges are limited to a single projectile of a particular configuration, the retention insert allows a second different or similar projectile to be arranged in a multiple projectile fixed cartridge. Therefore, a total mass of projectiles discharged in the multiple projectile fixed cartridges described herein may be greater than conventional cartridges, and thus, associated inertia is also larger, and therefore, a reduced velocity of discharge is achievable while maintaining appropriate recoil forces necessary to fully cycle a weapon. In this manner, a variety of different projectile configurations including subsonic configurations may be extensible to any desired implementation of exemplary embodiments of the present invention, without detracting from the functionality of a weapon, and while allowing multiple projectiles to be presented to a target. Hereinafter, a more detailed explanation of possible configurations of multiple projectile fixed cartridge designs is provided with reference to the many drawings.

FIGS. 1A-1Cillustrate several views of a multiple projectile fixed cartridge100and an associated retention insert105, according to embodiments of the disclosure. As illustrated, the cartridge100generally includes a casing101and at least two projectiles102,103arranged therein. The casing101can be a cylindrical casing having a central axis X′ and a radial axis R′. It will be understood that while the cartridge100is generally shown as a center-fire type cartridge with a bottle-necked configuration, other types or configurations of cartridges also can be used.

As shown inFIGS. 1A-1B, the casing101can include a neck portion104, shoulder portion106(here shown as having a tapered or bottleneck configuration) arranged proximate the neck portion104, and cylindrical body107arranged proximate the shoulder portion106. The neck portion104may be sized, crimped, or otherwise constrained about the projectile103. In this manner, the neck portion104can support the projectile103so as to maintain a collinear alignment of a central axis of the projectile103along the central axis X′ of the casing101. The neck portion104, shoulder portion106, and cylindrical body107also may be otherwise shaped or arranged without departing from the scope of this disclosure.

The cartridge100further includes a retention insert105arranged therein and configured to support and align projectile102. In this manner, the insert105supports the projectile102and maintains a collinear alignment of a central axis of the projectile102, the central axis of the projectile103, and the central axis X′. Generally, the retention insert105is configured to restrain radial movement of the projectile102relative to the casing101and the projectile103.

As further illustrated inFIG. 1B, the casing101may include an annular recess141arranged in a rearward section of the cylindrical body107and an associated rim142. The annular recess141and rim142may be configured to allow automatic expulsion of a spent casing.101or a fully loaded casing101when cycling a weapon. The recess141and rim142may be omitted or otherwise shaped or arranged without departing from the scope of this disclosure.

According to one embodiment, such as shown inFIG. 1B, the projectile102may be a generally cylindrical projectile having a rear portion121and a front, portion122. The projectile103may be a generally cylindrical projectile having a rear portion131and a front portion132. The rear portion131of the projectile103also may include a cavity or recess133of otherwise can be shaped or configured to receive and support the front portion122of the first or rearward projectile102. The rear portion121of projectile102may be similarly-shaped or configured as projectile103so as to facilitate receipt of an additional projectile arranged rearward therefrom. Thus, as shown inFIG. 1B, the projectiles102,103may be mounted/located along the casing101in a generally nested configuration. The projectile103may have a total length L1, and the projectile102may have a total length L2. The length L1may be greater than, shorter than, or substantially equal to the length L2. The projectiles102,103also may be otherwise shaped or configured without departing from the scope of this disclosure.

The neck portion104of the casing101shown inFIGS. 1A-1Bgenerally defines a projectile receiving portion112configured to receive the projectiles102,103, and the insert105, and a primer receiving portion113configured to receive a primer114. The casing further includes a flash hole115configured to transmit energy from the primer114into a central chamber or cavity111of the casing101. The central cavity111of the casing101generally is a substantially hollow cavity configured to support a propellant charge. The primer114, flash hole115, and central cavity111may be otherwise shaped or arranged without departing from the scope of this disclosure.

As illustrated inFIGS. 1B-5, the retention insert105is arranged within the cavity/chamber111of the casing101and can abut against the shoulder portion106. As a result, the retention insert105can engage an interior surface of the casing, such as along the neck portion104and prevent longitudinal movement relative thereto. For example, as shown inFIG. 1C, the retention insert105may include an elongated body145having one or more sections including a frustoconical section152shaped to engage and/or project along the shoulder portion106from an interior of the casing101. The body145of the insert105may further include a first or forward tapered cylindrical section151proximate the frustoconical section152, arranged to align and support the projectile102within a cavity154formed within the cylindrical portion151. The cavity154may have a geometry that is supportive, or generally supportive, of the exterior dimensions of the projectile102. As further illustrated, the projectile102is generally supported in a radial direction within the tapered cylindrical portion151.

The body145of the insert105further may include a rearwardly extending skirted or second cylindrical section150. The section150may be a hollow section and/or may support a secondary supportive insert. The section150can include an outer sidewall153with a first or forward beveled surface156proximate the tapered cylindrical section151of the body145and a second or rearward surface157proximate a distal end158of the section150and which also can be formed as a beveled surface. The beveled surfaces156,157of the section150are arranged to receive and guide energy from expanding combustion gases formed from ignition of the propellant in cavity111to the projectiles102,103and thereby discharge the projectiles102,103out of the casing101and along the barrel of a firearm.

According to one embodiment, the retention insert105generally is formed of a plastic material, including but not limited to, for example, a thermoplastic, acrylic, polyester, silicone, polyurethane, polymer or any other suitable plastic material. According to another embodiment, the retention insert105is formed of a metallic material, metal, or metal alloy, including but not limited to aluminum, brass, steel, or any other suitable metal or metallic material. According to other embodiments, the retention insert may be formed of any other suitable material, including those not listed specifically above. The retention insert105, and associated features150,151,152,153,154,156,157,158thereof may be otherwise shaped or arranged without departing from the scope of this disclosure.

As described above, a multiple projectile fixed cartridge may include a casing, a retention insert arranged in the casing, and a plurality of projectiles arranged proximate and within the retention insert or casing, wherein the retention insert is configured to align and support at least a first projectile (e.g.,102) of the plurality of projectiles, and the casing is configured to align and support a second projectile (e.g.,103) of the plurality of projectiles. Additional configurations of projectiles (e.g., three or more) also can be used.

The projectiles may be arranged to be supportive of one another through a rear section (e.g.,131) being configured to receive and support a front portion (e.g.,122) of another projectile. However, the same may be varied in many ways. For example, other arrangements of projectiles lacking discrete supportive rear sections may be applicable to some embodiments, such as illustrated inFIG. 2.

FIG. 2is a cross section view of a multiple projectile fixed cartridge200, according to an additional embodiment of the disclosure. The cartridge200may include some substantially similar components as the cartridge100, with like reference numerals representing like elements. As shown, the cartridge200includes a casing101with projectiles202,203arranged therein. The casing101is a cylindrical casing having a central axis X′ and a radial axis R′. The neck portion104may be sized, crimped, or otherwise constrained about the projectile203. In this manner, the neck portion104supports the projectile203and maintains a collinear alignment of a central axis of the projectile203and the central axis X′. The cartridge200further includes the retention insert105arranged therein and configured to support and align projectile202. In this manner, the insert105supports the projectile202and maintains a collinear alignment of a central axis of the projectile202, the central axis of the projectile203, and the central axis X′.

According to one embodiment, the projectile202may be a generally cylindrical projectile having a generally flat rear portion221, a front portion222, and a generally flat nose section223. The projectile203may be a generally cylindrical projectile having a generally flat rear portion231, a front portion232, and a generally flat nose section233. The generally flat rear portion231may be abutted against the nose section223. Thus, the projectiles202,203may be in an end-to-end abutted configuration. The projectile202may have a total length L3, and the projectile203may have a total length L4. The length L3may be greater than, shorter than, or substantially equal to the length L4. The projectiles202,203may be otherwise shaped or configured without departing from the scope of this disclosure.

As illustrated, the retention insert105is arranged within the cavity111and abutted against the shoulder portion106. The retention insert105can include the elongated body145having the frustoconical section152shaped to engage the shoulder portion106of the casing101. The insert body145further may include the tapered cylindrical portion151proximate the frustoconical portion152, arranged to align and support the projectile202within a cavity154formed within the forward or first tapered cylindrical portion151. The cavity154may have a geometry that is supportive, or generally supportive, of the exterior dimensions of the projectile202. As further illustrated, the projectile202is generally supported in a radial direction within the tapered cylindrical portion151substantially aligned with the projectile203along the longitudinal axis X′. The insert body145may further include the formation150, and the formation150may function to discharge and propel the projectiles202,203as described above. The retention insert105, and associated features150,151,152,153,154,156,157,158thereof may be otherwise shaped or arranged without departing from the scope of this disclosure.

As described above, the multiple projectile fixed cartridge may include a casing, a retention insert arranged in the casing, and a plurality of projectiles arranged proximate and within the retention insert or casing, wherein the retention insert is configured to align and support at least a first projectile (e.g.,202) of the plurality of projectiles, and the casing is configured to align and support a second projectile (e.g.,203) of the plurality of projectiles. The projectiles may be arranged to be supportive of one another through a flattened rear section (e.g.,231) configured to abut a nose section (e.g.,223) of another projectile, and additional projectiles also can be used.

As further described above, with reference to bothFIGS. 1 and 2, expanding combustion gases from the propellant will propel the first projectile (e.g.,102,202) against the second projectile (e.g.,103,203) and thereby propel both projectiles forward. However, such propulsion of the projectiles also may be varied. For example, other arrangements of the projectiles and the insert of the present invention, configured to enhance direction and control of expanding combustion gases also may be applicable to some embodiments, as illustrated inFIG. 3.

FIG. 3is a cross section view of a multiple projectile fixed cartridge300, according to a further embodiment of the disclosure. The cartridge300may include some substantially similar components as the cartridges100,200, with like reference numerals representing like elements. As shown, the cartridge300includes the casing101and projectiles102,103arranged therein. The casing101is a cylindrical casing having a central axis X′ and a radial axis R′. The neck portion104may be sized, crimped, or otherwise constrained about the projectile103as described above. The cartridge300further includes a retention insert305arranged therein and configured to support and align projectile102. In this manner, the insert305supports the projectile102and maintains a collinear alignment of a central axis of the projectile102, the central axis of the projectile103, and the central axis X′.

As illustrated, the retention insert305is arranged within the cavity/chamber111of the casing101and can abut against the shoulder portion106. As a result, the retention insert305can engage an interior surface of the casing, such as along the neck portion104and prevent longitudinal movement relative thereto. For example, as shown inFIG. 3, the retention insert305may include an elongated body345having one or more sections including a frustoconical section352shaped to engage and/or project along the shoulder portion106from an interior of the casing101. The body345of the insert305may further include a first or forward tapered cylindrical section351proximate the frustoconical section352, arranged to align and support the projectile102within a cavity358formed within the tapered cylindrical portion351. The cavity358may have a geometry that is supportive, or generally supportive, of the exterior dimensions of the projectile102. As further illustrated, the projectile102is generally supported in a radial direction within the cylindrical portion351.

The body345of the insert305further may include a rearwardly extending skirted or second cylindrical section350. The section350may be a hollow section and/or may support a secondary supportive insert. The section350can include an outer sidewall353with a first or forward beveled surface356proximate the tapered cylindrical section351of the body345and a second or rearward surface357proximate a distal end358of the section350and which also can be formed as a beveled surface. The beveled surfaces356,357of the section350are arranged to receive and guide energy from expanding combustion gases formed from ignition of the propellant in cavity111to the projectiles102,103and thereby aid to discharge the projectiles102,103out of the casing101and along the barrel of a firearm.

As further illustrated, the retention insert305may include combustion ports354,355arranged to transmit expanding combustion gases formed from ignition of the propellant arranged in cavity111to a space371between projectiles102,103.

The combustion port354may include an inlet361arranged on the first beveled surface356, a longitudinal section363in communication with the inlet361, a curved or angled section365in communication with the longitudinal section363, and an exhaust367in communication with the curved section365and the space371. The longitudinal section363may extend in a longitudinal direction from the inlet361to the curved section365. The curved section365may curve radially towards the exhaust367. Thus, the inlet361may receive expanding combustion gases, the longitudinal section363may transmit the received gases, and the curved section365may direct the transmitted gases to the exhaust367such that the expanding gases may at least partially fill the space371.

The combustion port355may include an inlet360also arranged on the first beveled surface356, a longitudinal section362in communication with the inlet360, a curved or angled section364in communication with the longitudinal section362, and an exhaust366in communication with the curved section364and the space371. The longitudinal section362may extend in a longitudinal direction from the inlet360to the curved section364. The curved section364may curve radially towards the exhaust366. Thus, the inlet360may receive expanding combustion gases, the longitudinal section362may transmit the received gases, and the curved section364may direct the transmitted gases to the exhaust366such that the expanding gases may at least partially fill the space371.

The energy of the expanding combustion gases transmitted through the formation350and the ports354,355may thereby discharge the projectiles102,103out of the projectile receiving portion112and into a weapon which further directs the projectiles102,103. The retention insert305may be formed of the same or somewhat similar materials as those listed above with reference to the insert105. The retention insert305, and associated features350,351,352,353,354,355,356,357,358,360,361,362,363,364,365,366,367, may be otherwise shaped or arranged without departing from the scope of this disclosure.

As described above, the multiple projectile fixed cartridge may include a casing, a retention insert arranged in the casing, and a plurality of projectiles arranged proximate and within the retention insert or casing, wherein the retention insert is configured to align and support at least a first projectile (e.g.,102) of the plurality of projectiles, and the casing is configured to align and support a second projectile (e.g.,103) of the plurality of projectiles. The retention insert may include one or more ports (e.g.,354,355) arranged to receive, transmit, route, and direct expanding combustion gases to individual projectiles (e.g.,103) or a space between one or more projectiles (e.g.;371).

Although described with reference toFIG. 3as applying to projectiles shaped as the generally cylindrical projectiles102,103, the same may also be varied. For example, other arrangements of projectiles may be applicable to the insert305, as illustrated inFIG. 4.

FIG. 4is a cross section view of a multiple projectile fixed cartridge400, according to yet another embodiment of the disclosure. The cartridge400may include some substantially similar components as the cartridges100,200,300, with like reference numerals representing like elements. As shown, the cartridge400includes the casing101and projectiles202,203arranged therein. The casing101is a cylindrical casing having a central axis X′ and a radial axis R′. The neck portion104may be sized, crimped, or otherwise constrained about the projectile203as described above. The cartridge400further includes a retention insert305arranged therein and configured to support and align projectile202. In this manner, the insert305supports the projectile202and maintains a collinear alignment of a central axis of the projectile202, the central axis of the projectile203, and the central axis X′.

As illustrated, the retention insert305is arranged within the cavity111and abutted against the shoulder portion106. For example, the retention insert body345may include a frustoconical section352shaped to engage the shoulder portion106of the casing101. The insert body345further may include a tapered cylindrical portion351proximate the frustoconical portion352, arranged to align and support the projectile202within a cavity358formed within the tapered cylindrical portion351. The cavity358may have a geometry that is supportive, or generally supportive, of the exterior dimensions of the projectile202. As further illustrated, the projectile202is generally supported in a radial direction within the tapered cylindrical portion351substantially aligned with the projectile203along the longitudinal axis X′. The formation350may function to discharge and propel the projectiles202,203as described above.

As further illustrated, the retention insert305may include the combustion ports354,355arranged to transmit expanding combustion gases formed from ignition of the propellant in cavity111to a space372between projectiles202,203. The combustion port354,355may include the same or substantially similar sections as described above, which are arranged to receive and direct energy of expanding combustion gases as described above. The energy of the expanding combustion gases transmitted through the formation350and the ports354,355may thereby discharge the projectiles202,203out of the projectile receiving portion112and into a weapon which further directs the projectiles202,203. The retention insert305, and associated features350,351,352,353,354,355,356,357,358,360,361,362,363,364,365,366,367, may be otherwise shaped or arranged without departing from the scope of this disclosure.

As described above, the multiple projectile fixed cartridge may include a casing, a retention insert arranged in the casing, and a plurality of projectiles arranged proximate and within the retention insert or casing, wherein the retention insert is configured to align and support at least a first projectile (e.g.,202) of the plurality of projectiles, and the casing is configured to align and support a second projectile (e.g.,203) of the plurality of projectiles. The retention insert may include one or more ports (e.g.,354,355) arranged to receive, transmit, route, and direct expanding combustion gases to individual projectiles (e.g.,203) or a space between one or more projectiles (e.g.,372).

Although described with reference toFIGS. 1-4as applying to at least two projectiles (e.g.,101,102&202,203), the same may also be varied. For example, other arrangements and numbers of projectiles may be applicable to embodiments, as illustrated inFIGS. 5-7.

FIG. 5is a cross section view of a multiple projectile fixed cartridge500, according to an additional embodiment of the disclosure. The cartridge500may include some substantially similar components as the cartridges100,200,300,400, with like reference numerals representing like elements. As shown, the cartridge500includes the casing101and projectiles502,503, and504arranged therein. The casing101is a cylindrical casing having a central axis X′ and a radial axis R′. The neck portion104may be crimped or otherwise constrained about the projectile504. In this manner, the neck portion104supports the projectile504and maintains a collinear alignment of a central axis of the projectile504and the central axis X′. The cartridge100further includes a retention insert505arranged therein and configured to support and align projectiles502,503. In this manner, the insert505supports the projectiles502,503and maintains a collinear alignment of a central axis of the projectile502, the central axis of the projectile503, the central axis of the projectile504, and the central axis X′.

According to one embodiment, the projectile502may be a generally cylindrical projectile having a rear portion521and a front portion522. The projectile503may be a generally cylindrical projectile having a rear portion531and a front portion532. The rear portion531of the projectile503may be shaped, configured, or otherwise manipulated to receive and support the front portion522. The rear portion521may be similarly shaped or configured so as to facilitate receipt of an additional projectile arranged rearward therefrom. The projectile504may be a generally cylindrical projectile having a rear portion541and a front portion542. The rear portion541may be shaped or configured to receive and support the front portion532. Thus, the projectiles502,503,504may be mounted/located along the casing in a generally nested configuration. The projectile502may have a total length L5, the projectile503may have a total length L6, and the projectile504may have a total length L7. The length L5may be substantially equal to the length L6in one embodiment. The lengths L5& L6may be greater than shorter than, or substantially equal to the length L7. The projectiles502,503,504may be otherwise shaped or configured without departing from the scope of this disclosure.

The casing101further includes a projectile receiving portion112configured to receive the projectiles502,503,504, and the insert505.

As illustrated, the retention insert505is arranged within the cavity111and abutted against the shoulder portion106. Therefore, the retention insert505is configured to engage an interior surface of the casing and prevent longitudinal movement relative thereto. For example, the retention insert505may include an elongated body545having a frustoconical section552shaped to engage the shoulder portion106from an interior of the casing101. The insert body545may further include a first or forward tapered cylindrical portion551proximate the frustoconical portion552, arranged to align and support the projectiles502,503within a cavity554formed within the tapered cylindrical portion551. The cavity554may have a geometry that is supportive, or generally supportive, of the exterior dimensions of the projectiles502,503. As further illustrated, the projectiles502,503are generally supported in a radial direction within the cylindrical portion551.

The body545of the insert505may further include a rearwardly extending skirted or second cylindrical formation550. The formation550may be a hollow section and/or may support a secondary supportive. The formation550can include an outer side wall553with a first beveled surface556proximate the tapered cylindrical portion551of the body545and a second or rearward surface557proximate a distal end558of the formation550and which also can be formed as a beveled surface. The beveled surfaces556,557of the formation550are arranged to receive and guide energy from expanding combustion gases formed from ignition of the propellant in cavity111to the projectiles502,503,504and thereby discharge the projectiles502,503,504out of the casing and along the barrel of a firearm. The retention insert505may be formed of the same or somewhat similar materials as those listed above with reference to the inserts105,305. The retention insert505, and associated features550,551,552,553,554,556,557,558thereof may be otherwise shaped or arranged without departing from the scope of this disclosure.

As described above, the multiple projectile fixed cartridge may include a casing, a retention insert arranged in the casing, and a plurality of projectiles arranged proximate and within the retention insert or casing, wherein the retention insert is configured to align and support two or more projectiles (e.g.,502,503) of the plurality of projectiles, and the casing is configured to align and support an additional projectile (e.g.,504) of the plurality of projectiles.

The insert may additionally be configured to receive, transmit, and direct combustion gases, for example, as illustrated inFIGS. 6-7.

FIG. 6is an elevation view of the projectile receiving portion of the cartridge112of a multiple projectile fixed cartridge600, according to still another embodiment of the disclosure, andFIGS. 7A-7Bare cross-sectional views of the multiple projectile fixed cartridge600. The cartridge600may include some substantially similar components as the cartridges100,200,300,400,500, with like reference numerals representing like elements.

Turning toFIG. 7A, a first cross section view of the multiple projectile fixed cartridge600is illustrated. As shown, the cartridge600includes the casing101and projectiles502,503,504arranged therein. The casing101is a cylindrical casing having a central axis X′ and a radial axis R′. The neck portion104may be crimped or otherwise constrained about the projectile504as described above. The cartridge600further includes a retention insert605arranged therein and configured to support and align projectiles502,503. In this manner, the insert605supports the projectiles502,503and maintains a collinear alignment of a central axis of the projectile502, the central axis of the projectile503, the central axis of the projectile504, and the central axis X′.

As illustrated, the retention insert605is arranged within the cavity111and abutted against the shoulder portion106. Therefore, the retention insert605is configured to engage an interior surface of the casing and prevent longitudinal movement relative thereto. For example, the retention insert605may include an elongated body645having a frustoconical section652shaped to engage the shoulder portion106from an interior of the casing101. The insert body645may further include a tapered cylindrical portion651proximate the frustoconical portion652, arranged to align and support the projectiles502,503within a cavity673formed within the tapered cylindrical portion651. The cavity673may have a geometry that is supportive, or generally supportive, of the exterior dimensions of the projectiles502,503. As further illustrated, the projectiles502,503are generally supported in a radial direction within the tapered cylindrical portion651.

The insert body645may further include a rearwardly extending skirted or second cylindrical formation650. The formation650may be a hollow section and/or may support a secondary supportive insert. The formation650can include an outer side wall653having a first or forward beveled surface701proximate the tapered cylindrical portion651and a second or rearward surface702proximate a distal end703of the formation650and which also can be formed as a beveled surface. The beveled surfaces701,702of the formation650are arranged to receive and guide energy from expanding combustion gases formed from ignition of the propellant in cavity111to the projectiles502,503,504and thereby discharge the projectiles out of the casing and along the barrel of a firearm.

As further illustrated, the retention insert605may include combustion ports654,655arranged to transmit expanding combustion gases formed from ignition of the propellant chemistry arranged in cavity111to a space671between projectiles503,504.

The combustion port654may include an inlet660arranged on the first beveled surface701, a longitudinal section661in communication with the inlet660, a curved or angled section662in communication with the longitudinal section661, and an exhaust663in communication with the curved section662and the space671. The longitudinal section661may extend in a longitudinal direction from the inlet660to the curved section662. The curved section662may curve radially towards the exhaust663. Thus, the inlet660may receive expanding combustion gases, the longitudinal section661may transmit the received gases, and the curved section662may direct the transmitted gases to the exhaust663such that the expanding gases may at least partially fill the space671.

The combustion port655may include an inlet664also arranged on the first beveled surface701, a longitudinal section665in communication with the inlet664, a curved or angled section667in communication with the longitudinal section665, and an exhaust668in communication with the curved section667and the space671. The longitudinal section665may extend in a longitudinal direction from the inlet664to the curved section667. The curved section667may curve radially towards the exhaust668. Thus, the inlet664may receive expanding combustion gases, the longitudinal section665may transmit the received gases, and the curved section667may direct the transmitted gases to the exhaust668such that the expanding gases may at least partially fill the space671.

In addition to the ports645,655, the cartridge600may include additional ports to aid in directing expanding combustion gases to a space672between projectiles502,503as illustrated inFIG. 7B. As shown inFIG. 7B, the retention insert605may include combustion ports684,685arranged to transmit expanding combustion gases formed from ignition of the propellant chemistry arranged in cavity111to a space672between projectiles502,503.

The combustion port684may include an inlet690arranged on the first beveled surface701, a longitudinal section691in communication with the inlet690, a curved or angled section692in communication with the longitudinal section691, and an exhaust693in communication with the curved section692and the space672. The longitudinal section691may extend in a longitudinal direction from the inlet690to the curved section692. The curved section692may curve radially towards the exhaust693. Thus, the inlet690may receive expanding combustion gases, the longitudinal section691may transmit the received gases, and the curved section692may direct the transmitted gases to the exhaust693such that the expanding gases may at least partially fill the space672.

The combustion port685may include an inlet694also arranged on the first beveled surface701, a longitudinal section695in communication with the inlet694, a curved or angled section697in communication with the longitudinal section695, and an exhaust698in communication with the curved section697and the space672. The longitudinal section695may extend in a longitudinal direction from the inlet694to the curved section697. The curved section697may curve radially towards the exhaust698. Thus, the inlet694may receive expanding combustion gases, the longitudinal section695may transmit the received gases, and the curved section697may direct the transmitted gases to the exhaust698such that the expanding gases may at least partially fill the space672.

The energy of the expanding combustion gases transmitted through the formation650and the ports654,655,684,685may thereby discharge the projectiles502,503,504out of the projectile receiving portion112and into a weapon which further directs the projectiles502,503,504. The retention insert605may be formed of the same or somewhat similar materials as those listed above with reference to the inserts105,305,505. The retention insert605, and associated features650,651,652,653,654,655,660,661,662,663,664,665,667,668,684,685,690,691,692,693,694,695,697,698,701,702,703may be otherwise shaped or arranged without departing from the scope of this disclosure.

As described above, a multiple projectile fixed cartridge may include a casing, a retention insert arranged in the casing, and a plurality of projectiles arranged proximate and within the retention insert or casing, wherein the retention insert is configured to align and support two or more projectiles (e.g.,502,503) of the plurality of projectiles, and the casing is configured to align and support an additional projectile (e.g.,504) of the plurality of projectiles. The retention insert may include one or more ports (e.g.,654,655,684,685) arranged to receive, transmit, route, and direct expanding combustion gases to individual projectiles (e.g.,503,504) or a space between one or more projectiles (e.g.,671,672).

Hereinafter, a brief description of the manufacture of multiple projectile fixed cartridges is provided with reference toFIG. 8.

FIG. 8is a flowchart of a method800of manufacturing a multiple projectile fixed cartridge, according to embodiments of the disclosure. The method800may include forming or obtaining a casing for forming a cartridge as indicated at block801. The forming operation may include casting, milling, cleaning, drawing, and/or other methods for forming a suitable material into a casing. The formed or obtained casing may be substantially similar to casing101, or may include or omit one or more features described herein.

The method800further includes populating the casing with cartridge components at block802, which may include, at least, pressing a primer into a primer receiving portion of the formed casing, inserting a propellant charge into a central cavity of the casing, inserting the retention insert into the casing, and inserting a plurality of projectiles into the retention insert and/or casing. Inserting the retention insert may occur after insertion of projectiles into the retention insert, or may occur in reverse according to some embodiments.

The method800further includes forming a neck portion and/or crimping a neck portion about a single projectile of the plurality of projectiles at block803. Forming the neck portion may occur after insertion of the retention insert but before insertion of the projectiles according to some embodiments. Thereafter, the neck portion may be crimped or otherwise engaged to constrain a neck portion of the casing about a projectile of the plurality of projectiles.

While the invention has been described in terms of exemplary embodiments, those skilled in the art will recognize that the invention can be practiced with modifications in the spirit and scope of the appended claims. The examples given above are merely illustrative and are not meant to be an exhaustive list of all possible designs, embodiments, applications, or modifications of the invention.