Abstract:
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.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to U.S. Provisional Patent Application No. 61/609,237, filed on Mar. 9, 2012, the entire contents of which are hereby incorporated by reference. 
    
    
     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 
     This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description of Illustrative Embodiments. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. 
     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. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The foregoing summary, as well as the following detailed description of preferred embodiments, is better understood when read in conjunction with the appended drawings. For the purposes of illustration, there is shown in the drawings exemplary embodiments; however, the presently disclosed invention is not limited to the specific methods and instrumentalities disclosed. In the drawings: 
         FIGS. 1A and 1B  are flow charts depicting one or more methods for making an article according to one or more embodiments disclosed herein; 
         FIG. 2  depicts components of a supersonic PCA article with a  FIG. 5  projectile according to one or more embodiments disclosed herein; 
         FIGS. 3A ,  3 B,  3 C, and  3 D depict components of a subsonic PCA article with a  FIG. 6  projectile according to one or more embodiments disclosed herein; 
         FIG. 4  depicts components of a subsonic PCA article with a core sleeve according to one or more embodiments disclosed herein; 
         FIG. 5  depicts a .308 cal. full metal jacket boat tail projectile according to one or more embodiments disclosed herein; 
         FIG. 6  depicts  FIG. 5  with a tapered trailing end (“projectile tapered trailing end” or “PTTE”) according to one or more embodiments disclosed herein; 
         FIG. 7  depicts a cold formed or a molded base cap according to one or more embodiments disclosed herein; 
         FIG. 8  depicts an injected molded core sleeve according to one or more embodiments disclosed herein; 
         FIG. 9  depicts a mold for molding a polymer casing that is segmented for heat cycling according to one or more embodiments disclosed herein. 
         FIG. 10  depicts  FIG. 5  projectile and a core pull inserted in a mold for making a supersonic casing according to one or more embodiments disclosed herein; 
         FIG. 11  depicts a casing made in the  FIG. 10  according to one or more embodiments disclosed herein, 
         FIG. 12  depicts a supersonic PCA article made with the  FIG. 11  casing according to one or more embodiments disclosed herein; 
         FIG. 13  depicts  FIG. 6  projectile and a core pull inserted in a mold for making a subsonic casing according to one or more embodiments disclosed herein; 
         FIG. 14  depicts a casing made in the  FIG. 13  according to one or more embodiments disclosed herein, 
         FIG. 15  depicts a subsonic PCA article made with the  FIG. 14  casing according to one or more embodiments disclosed herein; 
         FIG. 16  depicts a supersonic PCA article  FIG. 12  or a subsonic PCA article  FIG. 15  with a short neck casing according to one or more embodiments disclosed herein; 
         FIG. 17  depicts a supersonic PCA article  FIG. 12  or a subsonic PCA article FIG.  15  without a neck according to one or more embodiments disclosed herein; 
         FIGS. 18A and 18B  depict a projectile illustrated in  FIG. 6  projectile and a core pull inserted in a mold for making a subsonic casing with external ribs according to one or more embodiments disclosed herein; 
         FIGS. 19A and 19B  depict a casing made in the mold of  FIG. 18  according to one or more embodiments disclosed herein; 
         FIG. 20  depicts a subsonic PCA article made with the  FIG. 19  casing with external ribs according to one or more embodiments disclosed herein; 
         FIG. 21  depicts a subsonic PCA article made with  FIGS. 18 and 19  with both external ribs and collars according to one or more embodiments disclosed herein; 
         FIG. 22  depicts a mold with a core pull inserted in a mold for making a supersonic cavity sleeve (“cavity sleeve”) according to one or more embodiments disclosed herein; 
         FIG. 23  depicts a cavity sleeve made in the one or more embodiments illustrated in  FIG. 22  and according to one or more embodiments disclosed herein; 
         FIG. 24  depicts a subsonic PCA article converted to subsonic by use of the  FIG. 23  cavity sleeve according to one or more embodiments disclosed herein; 
         FIG. 25  depicts a subsonic PCA casing molded in  FIG. 25  over the core sleeve according to one or more embodiments disclosed herein; and 
         FIG. 26  depicts a subsonic PCA article made with  FIG. 26  casing according to one or more embodiments disclosed herein. 
     
    
    
     DETAILED DESCRIPTION 
     The presently disclosed invention is described with specificity to meet statutory requirements. However, the description itself is not intended to limit the scope of this patent; rather, the inventor(s) have contemplated that the claimed invention might also be embodied in other ways, to include different elements similar to the ones described in this document, in conjunction with other present or future technologies. Moreover, although the term “step” may be used herein to connote different aspects of methods employed, the term should not be interpreted as implying any particular order among or between various steps herein disclosed unless and except when the order of individual steps is explicitly described. 
     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 of  FIG. 1 , though many steps are optional and not limiting to the disclosure provided herein. As illustrated in  FIG. 1 , one or more methods for making an article are provided  100 . The one or more methods  100  may be applicable for any size and style article for small arms. The one or more methods  100  are particularly advantageous for manufacturing subsonic articles. The one or more methods  100  include several steps beginning with  102  which include determining the propellant charge composition, volume, and shape needed to achieve the ballistics required for a given PCA article. Step  104  of method  100  includes selecting a core pull that will produce a cavity corresponding to the propellant volume and shape required. Step  106  of method  100  includes inserting the projectile in a mold and seating the core pull in the mold against the base of the projectile. Step  108  of method  100  includes 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. Step  110  of method  100  includes removing the core pull and casing from the mold. Step  112  of method  100  includes 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, step  114  of method  100  includes attaching a primed base cap to the second end of the casing which completes the PCA article. 
       FIG. 1  also illustrates one or more methods  200  for making an article. The one or more methods  200  include converting a supersonic PCA casing made pursuant to one or more methods  100  contained in  FIG. 1  to 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 step  102  of method  100 , step  202  of method  200  includes 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 step  104  of method  100 , step  204  of method  200  includes 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 steps  106  through  110  of method  100 , steps  206  through  210  of method  200  include 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. Step  212  includes one or more methods of positioning the cavity insert in the method  100  PCA cavity. Like step  112  of method  100 , steps  214  and  216  of method  200  include inserting propellant charge in the cavity Insert and attaching a primed base cap to the second end of the casing; thereby, completing the method  200  PCA 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. 2  illustrates supersonic PCA article  1210  components. Casing  1118  is a structural supersonic component with a first end into which the projectile  510  is seated and cavity  1120  into which the propellant charge is loaded and to which a primed base cap  710  is 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. 3A  illustrates subsonic PCA article  1510  components which are similar to  FIG. 2  components except that casing  1418  is thicker and the cavity has a smaller diameter than  FIG. 2  and projectile  610  used herein has a tapered trailing end. 
       FIG. 3B  illustrates subsonic PCA article  2010  components which are similar to  FIG. 3  components except that casing  2020  has external ribs. 
       FIG. 3C  illustrates subsonic PCA article  2110  which is article  2010  with external collars around the casing as well as external ribs. 
       FIG. 3D  illustrates subsonic article  2410  components which include a supersonic PCA casing  1118  converted to a subsonic PCA casing  2318  by placing cavity insert  2320  in cavity  1120 , loading the propellant charge therein and attaching a primed base cap to the casing second end. 
       FIG. 4  illustrates subsonic PCA article  2410  components which include a polymer casing molded around a core sleeve, a primer  815  inserted in the primer cavity at the casing second end, and projectile  510  or  610  inserted in the neck after the propellant charge is loaded through the neck. 
       FIG. 5  illustrates a projectile  510  which 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. 5  depicts a .308 cal 220 grain full metal jacket boat-tail projectile. Unless the projectile trailing end is tapered as depicted in  FIG. 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 trailing  640 . 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 end  640  may 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. 6  illustrates projectile  610  which is  FIG. 5  with 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. 7  illustrates base cap  710  that 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 grooves  712  matching the ridges on the exterior of the casing trailing end and an exterior ejector ring  714  at the trailing end for extraction purposes. The bottom of the base cap has a primer cavity  716  into which a primer  717  is seated and a flash-hole  718  through which the propellant charge propellant charge is ignited when the primer is activated. 
       FIG. 8  illustrates a molded core sleeve including a  FIG. 7  base cap without grooves that is seamlessly attached to a cavity sleeve and neck. The neck may be short as in the case of  FIG. 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 a  FIG. 5  or  6  projectile which may or may not be textured. 
       FIG. 9  illustrates a universal mold  910  for producing PCA casings and is divided into three sections: the neck area  960 , shoulder area  940 , cavity area  930 , and case/base connection  920 . 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 12  illustrate supersonic PCA article  1210  from an associated mold  1050  according to one or more embodiments made according to the one or more methods  100 .  FIG. 10  illustrates an open mold  1050  with a projectile seat and a cavity profile of the casing outer dimensions (“mold cavity”). A projectile  510  is positioned in the projectile seat  1015  and a core pull  1016  is inserted in the mold and seated against the textured trailing end  540  of the projectile  510 . Polymer is injected through one or more gates in the mold and flows in the mold cavity  1017  around the core pull forming the cavity and around the projectile trailing end forming the shoulder  1018  and neck  1019 .  FIG. 11  illustrates casing  1120  molded in  FIG. 10  which reveals the cavity  1125  when the core pull  1016  is removed.  FIG. 12  illustrates casing  1120  with the propellant charge  1230  loaded in the cavity  1125  and a primed base cap  710  attached to the casing trailing end, thereby, completing the supersonic PCA article  1210 . 
       FIGS. 13 through 15  illustrate subsonic PCA article  1510  from an associated mold  1350  according to one or more embodiments made according to the one or more methods  100 .  FIG. 13  illustrates an open mold  1350  with a projectile seat  1315  and mold cavity  1317 . A projectile  610  is positioned in the projectile seat  1315  and a core pull  1316  is inserted in the mold and seated against the textured trailing end  640  of the projectile  610 . Polymer is injected through one or more gates in the mold and flows in the mold cavity  1317  around core pull  1316  forming the cavity and around the projectile trailing end, forming the shoulder  1318  and neck  1319 .  FIG. 14  illustrates a subsonic casing  1420  molded in  FIG. 13  which reveals the propellant cavity  1425 .  FIG. 15  illustrates casing  1420  with a propellant charge  1530  loaded in the cavity  1425  and a primed base cap  710  attached to the casing trailing end, thereby, completing subsonic PCA article  1510  with a smaller cavity and propellant charge but a thicker cavity wall. 
       FIG. 16  illustrates subsonic PCA article  1610  which is the same as PCA article  1510  except the casing neck  1619  is short because the polymer projectile seat  1315  provides the necessary neck tension and projectile stability. 
       FIG. 17  illustrates subsonic PCA article  1710  which is the same as PCA article  1510  except the casing  1720  has no neck  1727  the projectile  610  being held by the Shoulder and cavity casing. 
       FIGS. 18 through 21  illustrate subsonic PCA article  2110  with external ribs from an associated mold  1850  according to one or more embodiments made according to the one or more methods  100 .  FIG. 18  illustrates an open mold  1850  with a projectile seat  1815  and a mold cavity  1817  that reveals the casing outer dimensions including external longitudinal ribs. Projectile  610  is positioned in the projectile seat  1815  and a core pull  1816  is inserted in the mold and seated against the textured projectile trailing end  640 . Polymer is injected through one or more gates in the mold and flows in the mold cavity  1817  around the core pull forming the cavity  1925  and around the projectile tapered trailing end forming the shoulder  1818  and neck  1819 .  FIG. 19  illustrates a subsonic casing  1920  that was molded in  FIG. 18  which reveals the cavity  1920 .  FIG. 20  illustrates a subsonic casing  1920  with a propellant charge  2030  loaded in the cavity  1925  and a primed base cap  710  attached to the second end, thereby, completing subsonic PCA article  2010  with external ribs  1922 , thicker neck, and cavity walls and a smaller cavity and propellant charge. The ribs will lighten the casing while also strengthening the casing.  FIG. 21  is a modified design of  FIG. 20  which adds collars  2140  around the casing for strength.  FIG. 21  illustrates article  2110  that would be molded in  1850  with a modified mold cavity profile showing ribs and collars and would be assembled the same as  2010  but  2110  would have collars added. 
       FIGS. 22 through 24  illustrate a cavity sleeve  2324  from an associated mold  2250  according to one or more embodiments made according to the one or more methods  200 .  FIG. 22  illustrates an open mold  2250  tooled to mold cavity sleeves sized to fit in the cavity of supersonic casing  1120 . Core pull  2216  is inserted in mold  2250  and polymer is injected through one or more gates in the mold and flows in the mold cavity  2217  around the core pull forming cavity sleeve  2324 .  FIG. 23  illustrates the cavity sleeve  2324  which reveals a subsonic cavity  2325 . On either end of the cavity sleeve are two rings  2326  which have a membrane to contain the propellant charge if loaded before the sleeve is loaded in casing  1120 . Furthermore,  FIG. 23  illustrates a supersonic casing  1120  with a sleeve  2324  inserted therein; thereby, converting the supersonic casing  1120  into a subsonic casing  2328 .  FIG. 24  illustrates a converted casing  1120  with a subsonic propellant charge  2430  loaded in cavity  2325  and a primed base cap  710  attached to the casing second end, thereby, completing the conversion of a supersonic casing  1120  to a subsonic PCA article  2410  with a thicker cavity wall and a smaller cavity and propellant charge. 
       FIGS. 25 through 26  illustrate subsonic PCA article  2710  from an associated mold  2550  according to one or more embodiments made according to the one or more methods  300 .  FIG. 25  illustrates casing  2620  when the core pull is removed with the core sleeve remaining within the casing  2620 .  FIG. 26  illustrates casing  2620  with a subsonic polymer charge  2730  loaded in the cavity  2620  through the neck and projectile  510  inserted in the neck using one of several methods to create neck tension, thereby, completing the conversion of supersonic PCA casing  1120  to subsonic article  2710  with 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. 
     While the embodiments have been described in connection with the preferred embodiments of the various figures, it is to be understood that other similar embodiments may be used or modifications and additions may be made to the described embodiment for performing the same function without deviating therefrom. Therefore, the disclosed embodiments should not be limited to any single embodiment, but rather should be construed in breadth and scope in accordance with the appended claims.