Ammunition articles and methods for making the same

A method of making an ammunition article and associated ammunition article is provided. The ammunition article is interchangeable with standard ammunition articles and to operate in standard chambers of standard weapons systems and of the type having a casing including a sidewall that defines a casing volume within. The method includes determining a desired propellant charge volume for a given ammunition article, determining a thickness of the casing sidewall such that the casing volume substantially corresponds to the desired propellant charge volume, and forming the casing having the determined thickness.

TECHNICAL FIELD

This application is directed towards ammunition articles (“articles”) and methods for making the same, and, more particularly, towards a polymer cased ammunition (“PCA”) article having a propellant cavity (“cavity”) sized and shaped by being molded around a core pull (“core pull”) that optimally corresponds to the desired propellant charge volume and shape (“propellant charge”) whether the projectile (“projectile”) travels faster than the speed of sound (“supersonic”) or slower than the speed of sound (“subsonic”).

BACKGROUND

Ammunition articles typically are supersonic and generate an audible sound when the projectile travels at a speed greater than 1,100 feet per second during flight to the target (“supersonic articles”). This sound can be disadvantageous in military or covert operations because it may reveal the location where the supersonic article was discharged and ruin the element of surprise. Furthermore, noise can be an issue in law enforcement and commercial applications which needs to be abated.

Subsonic ammunition articles (“subsonic articles”) have been developed that do not produce the distinguishable audible sound associated with supersonic articles. Such articles typically have less muzzle flash, use oversized projectiles, use less powder volume and function in traditional gas operated weapons. The propellant charge usually is a small charge loaded in a large cavity or gun powder with a filler. Using a reduced propellant charge without sizing the cavity to the propellant charge leaves a partially filled cavity resulting in inconsistent propellant distribution, prohibits uniform ignition and significantly alters the burn profile. The reduced propellant charge may create lower pressures which makes consistent and complete case mouth obturation (“chamber sealing”) difficult and makes it hard to get a clean burn of the propellant causing rapid fouling of the weapon. In some cases, subsonic articles do not produce sufficient port pressure to enable subsonic articles to cycle properly in gas operated weapons.

The PCA articles and associated methods for making the same set forth herein address the above referenced disadvantages associated with conventional subsonic articles and methods. PCA articles presented herein generally have a thermal polymer based material (“polymer”) cartridge casing (“casing”) that holds a projectile in the first end (“neck”), and has a cavity and a base cap (“base cap”) attached to the casing second end. A subsonic PCA article may contain a core that is molded around a core pull containing a base cap, cavity sleeve, and a neck (“core sleeve” or “CS”).

It should be noted that articles contained herein are designed to function in existing weapons interchangeable with existing ammunition articles with functionality and performance improved over existing subsonic ammunition articles.

SUMMARY

Disclosed herein are PCA articles that may be supersonic or subsonic. The articles may have a) injection molded casings with the first end molded around the second end of a projectile that may be textured and may be tapered; b) a cavity sized by the core pull to the propellant charge; and c) a primed base cap, that may be molded metal in one or more embodiments that is attached to the casing second end. A tapered projectile trailing end provides a thicker/stronger casing neck and texturing provides proper neck tension without creating a “die-lock” condition and may reduce or eliminate the need for a casing neck. External ribs may be added to subsonic PCA casings to lighten and strengthen the casing walls. A supersonic PCA article may be converted to a subsonic PCA article. In one or more embodiments, a subsonic PCA article may have an overmolded core sleeve.

A method of making an ammunition article. The method includes providing a projectile having at least one portion that defines a texturing, injection molding in a mold a material around a core pull and a portion of the projectile to form a casing, and removing the core pull to form a propellant charge cavity within the casing.

According to one or more embodiments, a trailing end of the projectile about which material is molded around defines one of a boat tail or taper.

According to one or more embodiments, the casing defines a first end at which the projectile is molded around, and a second end, and the method further includes attaching a base cap to the second end.

According to one or more embodiments, injection molding a material includes injection molding one of a thermal polymer, ceramic, metal, or a composite.

According to one or more embodiments, the material in the step of injection molding a material includes one of a plasticizer, lubricant, molding agent, filler, thermo-oxidative stabilizers, flame-retardants, coloring agents, compatibilizers, impact modifiers, release agents, and reinforcing fibers.

According to one or more embodiments, the method includes loading a propellant charge in the cavity.

According to one or more embodiments, loading a propellant charge in the cavity comprises loading one of a gun powder or a composite of propellant materials that are substantially free of filler material and that occupy substantially all of the predetermined propellant charge volume.

According to one or more embodiments, the method includes preheating the projectile and molding into which the core pull is placed, and cycling heat in the mold including inductive heating.

According to one or more embodiments, injection molding around the core pull defines an area of increased thickness.

According to one or more embodiments, injection molding around the one of the boat tail or taper defines a seat against which the projectile abuts, and further wherein injection molding around the one of the boat tail or taper defines an area of increased thickness compared to a portion molded around a portion of the projectile that does not define one of a boat tail or taper.

According to one or more embodiments, the ammunition article is free of a neck portion about the projectile.

According to one or more embodiments, the mold defines one or more ribs and collars to thereby define corresponding ribs and collars on the casing after the step of injection molding in a mold.

According to one or more embodiments, the method includes inserting a sleeve into the propellant charge cavity to reduce the volume of the propellant charge cavity.

According to one or more embodiments, the method includes providing a base cap that is cold formed from metal or injection molded from polymer, ceramic, metal, or a composite material and into which a primer is inserted to ignite the propellant charge.

According to one or more embodiments, a method of making an ammunition article is provided. The method includes determining a desired propellant charge volume for a given ammunition article, determining one or more dimensions of a casing such that a cavity defined therein has a volume that substantially corresponds to the desired propellant charge volume, and forming the casing having the one or more dimensions.

According to one or more embodiments, the ammunition article has one of a predetermined length and caliber.

According to one or more embodiments, the diameter of the cavity generally corresponds to the diameter of a trailing end of the projectile.

According to one or more embodiments, the one or more dimensions includes at least one of an interior diameter and length of the cavity, and a cross-section of the casing.

According to one or more embodiments, a method of making a subsonic ammunition article is provided. The method includes providing a sleeve having a cavity and that is positioned proximal a projectile, and injection molding, in a mold, a material around the sleeve to form a casing.

According to one or more embodiments, the sleeve is molded at one station and the polymer based casing is molded around the sleeve in a mold at a second station

According to one or more embodiments, a primer is inserted in a primer seat at a trailing end of the casing, a propellant charge is loaded in the cavity through a neck of the ammunition article, and inserting the projectile into the neck.

According to one or more embodiments, a method of making an ammunition article is provided. The method includes injection molding a polymer material around a core pull to form a propellant casing such that the core pull defines a volume of the casing when removed for containing a propellant charge volume that corresponds to a desired ammunition charge.

According to one or more embodiments, the method includes injection molding around a projectile.

According to one or more embodiments, the casing defines a first end at which the projectile is molded around, and a second end. The method further includes attaching a base cap to the second end.

According to one or more embodiments, the method includes providing a propellant charge inside of the casing and a further including providing a primer for igniting the propellant charge.

According to one or more embodiments, the method includes molding the base cap from a polymer.

According to one or more embodiments, the method includes providing a metallic casing into which the core pull is inserted into before injection molding.

According to one or more embodiments, the propellant charge occupies substantially all of the predetermined propellant charge volume.

According to one or more embodiments, the propellant charge is substantially free of a filler material.

According to one or more embodiments, the propellant charge is one or gun powder and cordite and the propellant charge volume corresponds to a subsonic ammunition charge for a given projectile.

According to one or more embodiments, the method includes providing a metallic outer casing that has a first end configured for receiving a projectile and a second end configured for receiving a base cap, inserting the core pull through the first end into the casing, and injection molding through a gate defined in the second end.

According to one or more embodiments, the method includes providing a metallic outer casing that has a first end configured for receiving a projectile and a second end configured for receiving a base cap, inserting the core pull through the first end into the casing, and injection molding through a gate defined in the casing.

According to one or more embodiments, the method includes providing a metallic outer casing that has a first end configured for receiving a projectile and a second end configured for receiving a base cap, inserting the core pull through the first end into the casing, and injection molding through a gate defined in the core pull.

According to one or more embodiments, the gate is defined in a portion of the core pull proximal the first end of the casing.

According to one or more embodiments, the core pull defines a plurality of gates.

According to one or more embodiments, a method of making a subsonic ammunition article is provided. The method includes injection molding a polymer material around a core pull to form a propellant casing of an increased thickness such that the core pull defines a volume of the casing when removed for containing a propellant charge that corresponds to a subsonic ammunition charge.

According to one or more embodiments, the method includes removing the core pull such that the core pull volume defines the casing volume.

According to one or more embodiments, the method includes injection molding around a projectile.

According to one or more embodiments, the casing define a first end at which the projectile is molded around, and a second end, and the method further includes attaching a base cap to the second end.

According to one or more embodiments, the method includes providing a propellant charge inside of the casing and a further including providing a primer for igniting the propellant charge.

According to one or more embodiments, the method includes molding the base cap from a polymer.

According to one or more embodiments, the method includes providing a metallic casing into which the core pull is inserted into before injection molding.

According to one or more embodiments, the method further includes providing a metallic casing that has a first end configured for receiving a projectile and a second end configured for receiving a base cap, inserting the core pull through the first end into the casing, and injection molding through a gate defined in the second end.

According to one or more embodiments, the method includes providing a metallic casing that has a first end configured for receiving a projectile and a second end configured for receiving a base cap, inserting the core pull through the first end into the casing, and injection molding through a gate defined in the casing.

According to one or more embodiments, the method includes providing a metallic casing that has a first end configured for receiving a projectile and a second end configured for receiving a base cap, inserting the core pull through the first end into the casing, and injection molding through a gate defined in the core pull.

According to one or more embodiments, the gate is defined in a portion of the core pull proximal the first end of the casing.

According to one or more embodiments, a method of making an ammunition article is provided. The ammunition article is of the type having a casing that defines a volume therein. The method includes determining a desired propellant charge volume for a given ammunition article, determining one or more dimensions of the casing such that the casing volume substantially corresponds to the desired propellant charge volume, and forming the casing having the one or more dimensions.

According to one or more embodiments, the ammunition article has one of a predetermined length and caliber.

According to one or more embodiments, the ammunition article is a subsonic ammunition article.

According to one or more embodiments, the diameter of the casing volume generally corresponds to the diameter of a projectile to which the casing carries.

According to one or more embodiments, the one or more dimensions includes one of the interior diameter of the casing, the length of the casing, and the cross-section of the casing.

According to one or more embodiments, a method of making an ammunition article having a casing including a sidewall that defines a casing volume therein is provided. The method includes determining a desired propellant charge volume for a given ammunition article, determining a thickness of the casing sidewall such that the casing volume substantially corresponds to the desired propellant charge volume, and forming the casing having the determined thickness.

According to one or more embodiments, an ammunition article is provided. The article includes a casing having a first end that carries a projectile and a second end that carries a base cap, and a portion polymer within the casing, the portion of polymer defining a volume therein that contains a propellant charge.

According to one or more embodiments, the propellant charge corresponds to a subsonic ammunition charge.

According to one or more embodiments, the polymer within the casing is formed by injection molding a polymer material around a core pull such that the core pull defines a volume of the casing when the core pull is removed.

According to one or more embodiments, injection molding a polymer material comprises injection molding through a gate defined in the base cap.

According to one or more embodiments, injection molding a polymer material comprises injection molding through a gate defined in the casing.

According to one or more embodiments, injection molding a polymer material comprises injection molding through a gate defined in the casing.

According to one or more embodiments, the casing is one of metal and a polymer.

According to one or more embodiments, an ammunition article is made according to a process that includes determining a desired propellant charge volume for a given ammunition article, determining a thickness of the casing sidewall such that the casing volume substantially corresponds to the desired propellant charge volume, and forming the casing having the determined thickness.

DETAILED DESCRIPTION

Provided herein are one or more methods for making an article and associated articles. One or more steps are provided below and in the flow chart ofFIG. 1, though many steps are optional and not limiting to the disclosure provided herein. As illustrated inFIG. 1, one or more methods for making an article are provided100. The one or more methods100may be applicable for any size and style article for small arms. The one or more methods100are particularly advantageous for manufacturing subsonic articles. The one or more methods100include several steps beginning with102which include determining the propellant charge composition, volume, and shape needed to achieve the ballistics required for a given PCA article. Step104of method100includes selecting a core pull that will produce a cavity corresponding to the propellant volume and shape required. Step106of method100includes inserting the projectile in a mold and seating the core pull in the mold against the base of the projectile. Step108of method100includes injecting polymer through a gate in the mold cavity and around the core pull and the projectile trailing end, thereby, creating a casing molded around a portion of the projectile and having a cavity sized and shaped to receive the required propellant charge when the core pull is removed. If one desires an article having a smaller cavity to accommodate a reduced propellant charge volume, a smaller core pull would be selected. For example, if one desires a cavity with a 5 millimeter inner diameter instead of a 9.5 millimeter inner diameter, a core pull having a 5 millimeter diameter would be selected. In this manner, the mold cavity and core pull define the cavity wall thickness. Step110of method100includes removing the core pull and casing from the mold. Step112of method100includes loading the propellant charge in the cavity which may be gun powder or other appropriately configured materials that are substantially free of a filler material. In this manner, the propellant charge can be of high quality material for improved ignition characteristics and the propellant charge will occupy substantially all of the cavity volume. As used herein, “substantially all” means a cavity volume in which any unfilled space in the cavity after the propellant charge has been loaded is small in portion. Finally, step114of method100includes attaching a primed base cap to the second end of the casing which completes the PCA article.

FIG. 1also illustrates one or more methods200for making an article. The one or more methods200include converting a supersonic PCA casing made pursuant to one or more methods100contained inFIG. 1to a subsonic PCA casing by inserting a sleeve in the supersonic PCA cavity; thereby, converting the cavity from supersonic to subsonic. The sleeve whether injection molded or otherwise formed will reduce the cavity to the desired volume and shape once inserted. Like step102of method100, step202of method200includes determining the desired propellant charge volume and shape which takes into consideration the type of ammunition powder or charge, the size and weight of a projectile, and other factors. Like step104of method100, step204of method200includes determining the cavity dimensions that correspond to the desired propellant charge volume and shape and selecting a core pull that will produce such dimensions. For example, if a subsonic article is desired whereby the projectile muzzle velocity is less than 1,100 feet per second (340 meters per second), the cavity dimensions can be selected to match the propellant charge volume and shape needed to achieve the desired performance characteristics. In one or more embodiments, the cavity sidewall may be uniform throughout any given cross-section of the cavity, whereas, in one or more additional embodiments, the cavity may not be uniform and may instead take on any optimally configured or desired cross-section. For example, the cavity sidewall may include a plurality of stepped-up and stepped-down portions or other desired configuration. Like steps106through110of method100, steps206through210of method200include one or more methods of positioning the core pull in a mold designed to produce the cavity Insert, forming the insert by injecting molding polymer around the core pull and removing the cavity Insert from the mold. Step212includes one or more methods of positioning the cavity insert in the method100PCA cavity. Like step112of method100, steps214and216of method200include inserting propellant charge in the cavity Insert and attaching a primed base cap to the second end of the casing; thereby, completing the method200PCA subsonic article. As an alternative, the propellant charge may be loaded before the cavity sleeve is loaded in the casing with a combustible membrane securing the propellant at each end.

FIG. 2illustrates supersonic PCA article1210components. Casing1118is a structural supersonic component with a first end into which the projectile510is seated and cavity1120into which the propellant charge is loaded and to which a primed base cap710is attached, thereby, completing the PCA. PCA casings must have the ability to deform under high ballistic pressures (“ductility”) and maintain reliable case integrity under extreme temperatures (negative 45 degrees to 165 degrees Fahrenheit) without cracking or splitting.

FIG. 3Aillustrates subsonic PCA article1510components which are similar toFIG. 2components except that casing1418is thicker and the cavity has a smaller diameter thanFIG. 2and projectile610used herein has a tapered trailing end.

FIG. 3Cillustrates subsonic PCA article2110which is article2010with external collars around the casing as well as external ribs.

FIG. 3Dillustrates subsonic article2410components which include a supersonic PCA casing1118converted to a subsonic PCA casing2318by placing cavity insert2320in cavity1120, loading the propellant charge therein and attaching a primed base cap to the casing second end.

FIG. 4illustrates subsonic PCA article2410components which include a polymer casing molded around a core sleeve, a primer815inserted in the primer cavity at the casing second end, and projectile510or610inserted in the neck after the propellant charge is loaded through the neck.

FIG. 5illustrates a projectile510which is attached to the first end of a casing by one of several methods. As illustrated herein, the first end of the casing is overmolded around the projectile trailing end. Although various size projectiles may be used in supersonic PCA articles,FIG. 5depicts a .308 cal 220 grain full metal jacket boat-tail projectile. Unless the projectile trailing end is tapered as depicted inFIG. 6, a boat-tail projectile is advantageously provided for use in PCA articles because the casing area molded around the projectile trailing end creates a seat (“projectile seat”) that prevents the projectile from compressing into the cavity. The projectile trailing end is textured except for the neck area as a method of creating appropriate neck tension when a casing is overmolded the projectile trailing640. Greater tension may require heavier texturing and less tension requires finer texturing. The neck area remains untextured to reduce stress on the neck/shoulder joint. Overmolding a projectile with canneluring creates a die-lock condition because polymer fills the canneluring groove during the overmolding process which causes neck failure when the PCA article is fired. A secondary benefit of texturing the projectile trailing end640may be greater stability in flight. The length of the overmolded textiled trailing end in the shoulder and cavity (“projectile seat”) may render the neck unnecessary to hold the projectile and provide necessary pull tension. Furthermore, head space is determined by the shoulder and not the neck for rifle ammunition articles. Reducing or eliminating the casing neck will reduce or eliminate instances of neck failure in PCA articles.

FIG. 6illustrates projectile610which isFIG. 5with a tapered trailing end to provide improved strength in the casing neck and neck/shoulder joint with about 2 millimeters of the projectile trailing end at the mouth of the casing unchanged and overmolded.

FIG. 7illustrates base cap710that is attached to the second end of a casing. The one or more methods may also include cold forming or injection molding the base cap from polymer, metal or a composite material. The base cap has a first end with internal grooves712matching the ridges on the exterior of the casing trailing end and an exterior ejector ring714at the trailing end for extraction purposes. The bottom of the base cap has a primer cavity716into which a primer717is seated and a flash-hole718through which the propellant charge propellant charge is ignited when the primer is activated.

FIG. 8illustrates a molded core sleeve including aFIG. 7base cap without grooves that is seamlessly attached to a cavity sleeve and neck. The neck may be short as in the case ofFIG. 16. There may be several rings evenly spaced along the overmolded which may also be textured. The base may have a ledge which together the rings and texturing prevent the polymer casing from sliding on the core sleeve or separating upon ejection. The cavity section of the sleeve is shaped and sized to match the propellant charge and the casing first end is shaped to receive aFIG. 5or6projectile which may or may not be textured.

FIG. 9illustrates a universal mold910for producing PCA casings and is divided into three sections: the neck area960, shoulder area940, cavity area930, and case/base connection920. Molding temperature may need to be the highest in the areas where the casing wall is the thinnest and lowest where the casing wall is the thickest, therefore, the molding temperature at the neck need to be the highest, the shoulder molding temperature needs to be the lowest and the cavity molding temperature needs to be moderately high. The mold needs to be segmented into three heat zones to accommodate the differing temperature requirements (“heat cycling”) of polymer as it enters the mold through a gate in the cavity at the casing trailing end and moves around the core pull and the projectile trailing forward to the mouth of the neck which is the thinnest casing wall. In one or more experiments, about five percent (5%) of the casing outer layer where the material enters the mold (“shear layer”) has little strength and radiates through the casing length. For example, a subsonic shear layer of 5% at the cavity is 22% of the neck wall unless a projectile tapered projectile is used. Heating the projectile to prevent it from becoming a heat-sink and prematurely cooling the polymer may be advantageous to avoid neck failure. Finally, intensive heating may be required to achieve proper temperature in the three mold segments which strengthens casing wall.

FIGS. 10 through 12illustrate supersonic PCA article1210from an associated mold1050according to one or more embodiments made according to the one or more methods100.FIG. 10illustrates an open mold1050with a projectile seat and a cavity profile of the casing outer dimensions (“mold cavity”). A projectile510is positioned in the projectile seat1015and a core pull1016is inserted in the mold and seated against the textured trailing end540of the projectile510. Polymer is injected through one or more gates in the mold and flows in the mold cavity1017around the core pull forming the cavity and around the projectile trailing end forming the shoulder1018and neck1019.FIG. 11illustrates casing1120molded inFIG. 10which reveals the cavity1125when the core pull1016is removed.FIG. 12illustrates casing1120with the propellant charge1230loaded in the cavity1125and a primed base cap710attached to the casing trailing end, thereby, completing the supersonic PCA article1210.

FIGS. 13 through 15illustrate subsonic PCA article1510from an associated mold1350according to one or more embodiments made according to the one or more methods100.FIG. 13illustrates an open mold1350with a projectile seat1315and mold cavity1317. A projectile610is positioned in the projectile seat1315and a core pull1316is inserted in the mold and seated against the textured trailing end640of the projectile610. Polymer is injected through one or more gates in the mold and flows in the mold cavity1317around core pull1316forming the cavity and around the projectile trailing end, forming the shoulder1318and neck1319.FIG. 14illustrates a subsonic casing1420molded inFIG. 13which reveals the propellant cavity1425.FIG. 15illustrates casing1420with a propellant charge1530loaded in the cavity1425and a primed base cap710attached to the casing trailing end, thereby, completing subsonic PCA article1510with a smaller cavity and propellant charge but a thicker cavity wall.

FIG. 16illustrates subsonic PCA article1610which is the same as PCA article1510except the casing neck1619is short because the polymer projectile seat1315provides the necessary neck tension and projectile stability.

FIG. 17illustrates subsonic PCA article1710which is the same as PCA article1510except the casing1720has no neck1727the projectile610being held by the Shoulder and cavity casing.

FIGS. 18 through 21illustrate subsonic PCA article2110with external ribs from an associated mold1850according to one or more embodiments made according to the one or more methods100.FIG. 18illustrates an open mold1850with a projectile seat1815and a mold cavity1817that reveals the casing outer dimensions including external longitudinal ribs. Projectile610is positioned in the projectile seat1815and a core pull1816is inserted in the mold and seated against the textured projectile trailing end640. Polymer is injected through one or more gates in the mold and flows in the mold cavity1817around the core pull forming the cavity1925and around the projectile tapered trailing end forming the shoulder1818and neck1819.FIG. 19illustrates a subsonic casing1920that was molded inFIG. 18which reveals the cavity1920.FIG. 20illustrates a subsonic casing1920with a propellant charge2030loaded in the cavity1925and a primed base cap710attached to the second end, thereby, completing subsonic PCA article2010with external ribs1922, thicker neck, and cavity walls and a smaller cavity and propellant charge. The ribs will lighten the casing while also strengthening the casing.FIG. 21is a modified design ofFIG. 20which adds collars2140around the casing for strength.FIG. 21illustrates article2110that would be molded in1850with a modified mold cavity profile showing ribs and collars and would be assembled the same as2010but2110would have collars added.

FIGS. 22 through 24illustrate a cavity sleeve2324from an associated mold2250according to one or more embodiments made according to the one or more methods200.FIG. 22illustrates an open mold2250tooled to mold cavity sleeves sized to fit in the cavity of supersonic casing1120. Core pull2216is inserted in mold2250and polymer is injected through one or more gates in the mold and flows in the mold cavity2217around the core pull forming cavity sleeve2324.FIG. 23illustrates the cavity sleeve2324which reveals a subsonic cavity2325. On either end of the cavity sleeve are two rings2326which have a membrane to contain the propellant charge if loaded before the sleeve is loaded in casing1120. Furthermore,FIG. 23illustrates a supersonic casing1120with a sleeve2324inserted therein; thereby, converting the supersonic casing1120into a subsonic casing2328.FIG. 24illustrates a converted casing1120with a subsonic propellant charge2430loaded in cavity2325and a primed base cap710attached to the casing second end, thereby, completing the conversion of a supersonic casing1120to a subsonic PCA article2410with a thicker cavity wall and a smaller cavity and propellant charge.

FIGS. 25 through 26illustrate subsonic PCA article2710from an associated mold2550according to one or more embodiments made according to the one or more methods300.FIG. 25illustrates casing2620when the core pull is removed with the core sleeve remaining within the casing2620.FIG. 26illustrates casing2620with a subsonic polymer charge2730loaded in the cavity2620through the neck and projectile510inserted in the neck using one of several methods to create neck tension, thereby, completing the conversion of supersonic PCA casing1120to subsonic article2710with a metal neck, a thicker cavity wall and a smaller cavity and propellant charge.

The one or more ammunition articles disclosed herein may have various advantages over conventional ammunition articles. As described, the ability to form a case cavity volume equal to the desired propellant charge propellant charge volume for a specified caliber and projectile is essential to achieve consistent desired ballistics. Additionally, the gap of unfilled area in the casing associated with, for example, conventional subsonic ammunition articles is reduced or eliminated. Furthermore, the casing strength may be increased due to the thickness of the sidewall and polymer cased ammunition articles will be lighter weight than metal articles of the same characteristics.