Patent Abstract:
An apparatus for manufacturing an ammunition article, includes forming a projectile of an ammunition article at a first station of an apparatus, transporting the projectile within the apparatus to a second station of the apparatus, and injection molding at the second station a cartridge casing body of the ammunition article around at least a portion of the projectile.

Full Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a divisional application of U.S. patent application Ser. No. 11/160,682, which is a continuation-in-part of U.S. patent application Ser. No. 10/912,162, filed on Aug. 6, 2004, which is a divisional of U.S. patent application Ser. No. 09/832,020, filed on Apr. 11, 2001 and now U.S. Pat. No. 6,845,716, which is a divisional of U.S. patent application Ser. No. 09/265,946, filed on Mar. 11, 1999 and now U.S. Pat. No. 6,752,084, and which claims the benefit of U.S. Provisional Application No. 60/116,232, filed Jan. 15, 1999. The subject matter of U.S. patent application Ser. No. 10/912,162, U.S. patent application Ser. No. 09/832,020, U.S. patent application Ser. No. 09/265,946, and U.S. Provisional Application No. 60/116,232 is incorporated herein by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates to ammunition articles and methods of making ammunition articles and, more particularly, to ammunition articles with plastic components such as cartridge casing bodies and bases, and methods of making ammunition articles with plastic components. 
       BACKGROUND AND SUMMARY 
       [0003]    Plastic cartridge casings have been known for many years but have failed to provide satisfactory ammunition that could be produced in commercial quantities with sufficient safety, ballistic, and handling characteristics. The problems evidenced by all of the known methods of producing plastic or substantially plastic ammunition include the possibility of the projectile being pushed into the cartridge casing, the bullet pull being too light such that the bullet can fall out, the bullet pull being insufficient to create enough chamber pressure, the bullet pull being too great causing excessive chamber pressure, the bullet pull not being uniform from round to round, portions of the cartridge casing breaking off upon firing of the projectile causing damage or danger when subsequent rounds are fired or when the casing portions themselves become projectiles, and expense due to manufacturing techniques or multiple material constructions. In the manufacture of blanks using plastic cartridge cases, similar problems to those present with prior art cartridge cases for conventional ammunition exist, as well as problems associated with portions of the cartridge cases breaking off and becoming dangerous, high velocity plastic projectiles. 
         [0004]    Certain of the foregoing problems are addressed in European Patent Application 
         [0005]    0131863, which discloses a plastic cartridge casing that is provided with a ring or a plurality of rings or with a pronounced radially inward taper to engage corresponding surfaces on the bullet so that the bullet may be snapped into the casing. However, the technique of forming a cartridge casing and then snapping a bullet into the casing is time consuming in that it involves multiple steps, is manpower and equipment intensive in that different equipment is necessary to perform various tasks in the manufacturing process, and still risks a less than perfect fit between bullet and casing in that the casings are not custom fit to each bullet. It is desirable to provide ammunition articles having plastic cartridge casing bodies, cartridge casings with plastic cartridge casing bodies, and plastic cartridge casing bodies that ensure a high-quality fit between the plastic cartridge casing body and the projectile, and methods of manufacture for such articles that are simple and require minimal manpower and equipment. 
         [0006]    According to one aspect of the present invention, an ammunition article is provided, the ammunition article including a molded plastic cartridge casing body having a first end and a second end, and a projectile attached to the first end of the cartridge casing body. The cartridge casing body is molded around at least a portion of the projectile. 
         [0007]    According to another aspect of the present invention, an ammunition article is provided, the ammunition article including a cartridge casing body having a first end and a second end, a projectile attached to the first end of the cartridge casing body, and a single piece, molded plastic base, the base being attached to the second end of the cartridge casing body. 
         [0008]    According to another aspect of the present invention, an ammunition article is provided, the ammunition article including a molded plastic cartridge case body having a closed front end and a second end. 
         [0009]    According to another aspect of the present invention, an ammunition article is provided, the ammunition article including a molded plastic cartridge case body, the cartridge case body including a web dividing an internal volume of the body to define a lower cavity for receiving a propellant and an upper cavity for receiving a projectile, the web including an upwardly extending prong for being received in a corresponding recess in a base of the projectile to fasten the body to the projectile. 
         [0010]    According to another aspect of the present invention, a method of making an ammunition article includes the steps of molding plastic around at least a portion of a projectile to form a plastic cartridge casing body having a first end to which the projectile is attached and a second end. 
         [0011]    According to another aspect of the present invention, a method of making an ammunition article includes the steps of molding plastic to form a single piece, molded plastic base, and attaching the base to an end of a cartridge casing body. 
         [0012]    According to another aspect of the present invention, a method of making an ammunition article includes the steps of molding plastic around a core pull to form a molded plastic cartridge case body having a closed front end and a second end, and removing the core pull from the cartridge casing body. 
         [0013]    According to another aspect of the present invention, a method of making an ammunition article includes the steps of molding plastic to form a molded plastic cartridge case body, the cartridge case body including a web dividing an internal volume of the body to define a lower cavity for receiving a propellant and an upper cavity for receiving a projectile, the web including an upwardly extending prong, and causing the upwardly extending prong to be received in a corresponding recess in a base of the projectile to fasten the body to the projectile. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]    The features and advantages of the present invention are well understood by reading the following detailed description in conjunction with the drawings in which like numerals indicate similar elements and in which: 
           [0015]      FIG. 1  is a top perspective view of an ammunition article according to a first embodiment of the present invention; 
           [0016]      FIG. 2  is a bottom perspective view of an ammunition article according to the first embodiment of the present invention; 
           [0017]      FIG. 3  is a side view of an ammunition article according to the first embodiment of the present invention; 
           [0018]      FIGS. 4A and 4B  are side, cross-sectional views of an ammunition article according to the first embodiment of the present invention; 
           [0019]      FIG. 5  is a top perspective view of a cartridge casing body according to the first embodiment of the present invention and illustrated without the projectile; 
           [0020]      FIG. 6  is a cross-sectional view of a portion of an ammunition article according to the first embodiment of the present invention; 
           [0021]      FIG. 7  is a cross-sectional view of an embodiment of a projectile for use in connection with the ammunition article according to the first embodiment of the present invention; 
           [0022]      FIG. 8  is a cross-sectional view of another embodiment of a projectile for use in connection with the ammunition article according to the first embodiment of the present invention; 
           [0023]      FIG. 9A  is a cross-sectional view of a portion of an ammunition article according to the first embodiment of the present invention; 
           [0024]      FIGS. 9B and 9C  are partial, top views of a portion of an ammunition article according to the first embodiment of the present invention, showing possible forms of flanges; 
           [0025]      FIG. 10  is a cross-sectional view of a portion of an embodiment of the ammunition article according to the first embodiment of the present invention shown after firing; 
           [0026]      FIG. 11  is a cross-sectional view of an embodiment of the ammunition article according to the first embodiment of the present invention; 
           [0027]      FIG. 12  is a cross-sectional view of a portion of an ammunition article according to the first embodiment of the present invention; 
           [0028]      FIG. 13A-14B  are partially cross-sectional views of molding equipment for making an embodiment of a cartridge casing body for an ammunition article according to the first embodiment of the present invention; 
           [0029]      FIG. 15  is a cross-sectional view of an assembly step according to a method for making an ammunition article according to the first embodiment of the present invention; 
           [0030]      FIG. 16  is an exploded view of an ammunition article according to a second embodiment of the present invention; 
           [0031]      FIG. 17  is an exploded, cross-sectional view of an ammunition article according to the second embodiment of the present invention; 
           [0032]      FIG. 18A  is a front perspective view of a molded plastic base according to an embodiment of the ammunition article according to the second embodiment of the present invention; 
           [0033]      FIG. 18B  is a side, cross-sectional view of a molded base according to an embodiment of the ammunition article; 
           [0034]      FIG. 19  is a rear perspective view of a molded plastic base according to an embodiment of the ammunition article according to the second embodiment of the present invention; 
           [0035]      FIG. 20  is a rear perspective view of an embodiment of a cartridge casing body for use with an embodiment of the ammunition article according to the second embodiment of the present invention; 
           [0036]      FIG. 21  is a partially cross-sectional view of molding equipment for making a plastic base for an ammunition article according to the second embodiment of the present invention; 
           [0037]      FIG. 22  is a side view of an ammunition article according to a third embodiment of the present invention; 
           [0038]      FIG. 23  is a partially cross-sectional view of molding equipment for making an ammunition article according to the third embodiment of the present invention; 
           [0039]      FIG. 24  is a front perspective view of a core pull for use in making an ammunition article according to the third embodiment of the present invention; 
           [0040]      FIG. 25  is a front end view of a core pull for use in making an ammunition article according to the third embodiment of the present invention; 
           [0041]      FIG. 26  is a side view of a core pull for use in making an ammunition article according to the third embodiment of the present invention; 
           [0042]      FIG. 27  is a side view of a core pull inserted in a partially broken ammunition article according to the third embodiment of the present invention; 
           [0043]      FIG. 28  is a side, cross-sectional view of a portion of an ammunition article according to a fourth embodiment of the present invention; 
           [0044]      FIG. 29  is a side, cross-sectional view of a portion of an ammunition article according to a fifth embodiment of the present invention; and 
           [0045]      FIG. 30  is a side, cross-sectional view of a portion of an ammunition article according to a sixth embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0046]    An ammunition article  21  according to an embodiment of the present invention is shown in  FIGS. 1-3 . As seen in cross-section in  FIGS. 4A and 4B , the ammunition article  21  includes a molded plastic cartridge casing body  23  having a first end  25  and a second end  27 . A projectile  29  is attached to the first end  25  of the cartridge casing body  23 . The cartridge casing body  23  is a molded plastic part, and is formed by plastic being molded around at least a portion  31  of the projectile  29 . As discussed with reference to  FIG. 29 , if desired or necessary, the cartridge casing body may be formed by plastic being molded to conform only with a bottom of a projectile, with a plastic protrusion extending into a cavity in the bottom of the projectile. The projectile  29  is preferably any one of the wide variety of well-known projectiles but may, if desired or necessary, include one or more features useful in connection with the present invention. 
         [0047]    As seen in  FIG. 5  (showing the cartridge casing body with the projectile removed for illustration) the cartridge casing body  23  preferably includes an interior volume  33  including a first interior portion  35  defined by the portion  31  of the projectile  29  and a second interior portion  37  having a smaller diameter than the first interior portion and being separated from the first interior portion by a shoulder  39 . As seen in  FIGS. 5 and 6 , the shoulder  39  is preferably of sufficient size to prevent axial movement of the projectile  29  into the second interior portion  37 . The second interior volume  37  is preferably formed by a core pull ( FIGS. 13A-14B ) used in a cartridge casing body molding operation wherein a leading end of the core pull preferably abuts against the base  40  of the projectile  29 . As seen in  FIG. 7 , the base  40  of the projectile may be flat or, as seen in  FIG. 8 , contoured, such as by being concave. The base  40  may be contoured to any shape desired or necessary, such as concave, convex, a combination of concave or convex, have straight portions, or curved portions, depending upon factors such as the ballistic requirements of the projectile. 
         [0048]    The projectile  29  is preferably attached to the cartridge casing body  23  by one or more attachment arrangements  41  directed to preventing axial movement of the projectile relative to the cartridge casing body prior to firing, such as during storage or shipment, and during accidents such as dropping of the ammunition article. Depending upon the type of ammunition article being manufactured, desirable characteristics of the attachment arrangement  41  may include the ability to provide sufficient bullet pull to permit creation of neither too much nor too little chamber pressure during firing of the projectile, ensuring uniform bullet pull from round to round, and avoiding causing portions of the cartridge casing body to break off when the ammunition article is fired. Suitable attachment arrangements  41  include a heat bond, an adhesive bond, and a weld, such as an ultrasonic weld, between the portion  31  of the projectile and the cartridge casing body  23 . The attachment arrangement may be a mechanical attachment arrangement wherein portions of the cartridge casing body  23  and the portion  31  of the projectile  29  are caused to interconnect. The attachment arrangement may, of course, be nothing more than a metal to plastic bond between the portion  31  of the projectile  29  and the cartridge casing body  23  created during the molding operation. 
         [0049]    A form of attachment arrangement  41 , seen in detail in  FIG. 9A , includes a flange  41 ′ on the cartridge casing body  23  extending into a recess  43  in the projectile  29 . Optimal dimensions for the flange  41 ′ will vary depending upon the specific type of ammunition article  21  to be made. When the cartridge casing body  23  is made of a modified ZYTEL resin, available from E.I. DuPont De Nemours Co., a modified 612 nylon resin, modified to increase elastic response, and the ammunition article is so-called A38 Special□type ammunition, a desirable dimension for an annular flange  41 ′ is 0.009″ thick by 0.020″ wide, i.e., the recess  43  is an annular recess in the projectile  29  that is about 0/009″ thick by 0.020″ wide. The flange  41 ′ and the recess  43  are not limited to being annular, and can be any of a variety of shapes and sizes, such as pins and grooves, detents and detent receiving recesses, helixes, such as screw threads, or any other suitable mechanically interconnectable structure sufficient to retain the projectile  29  in position in the cartridge casing body  23 . By proper selection of materials and flange  41 ′ and recess  43  size, it is possible to design to a very exact degree features of the ammunition article  21  such as bullet pull. As seen in  FIGS. 9B and 9C , the flange  41 ′ need not be continuous around the entire circumference of the projectile, such as in the embodiment shown in  FIG. 5 , but may be in the form of multiple, discontinuous or interrupted forms. The shape of the flange  41 ′ may be any suitable shape, such as a cone, a pyramid, a half-sphere, a half circular cylinder, a cube, or other geometrical form. 
         [0050]    As seen in  FIG. 10 , the flange  41 ′, when provided, is preferably sized such that, and the cartridge casing body  23  is preferably made of a plastic material suitable for its specific intended application such that, upon firing of the projectile  29 , the flange  41 ′ breaks off from the rest of the body  23  and is carried off with the projectile, without also causing other portions of the body  23  to break off. If desired or necessary, multiple flanges  41  and recesses  43  can be arranged along a length of the cartridge casing body  23  and the portion  31  of the projectile  29 . It will be understood that an ammunition article  21  with a flange  41 ′ is just one embodiment of the present invention, and that the flange may be omitted in favor of one or more alternative attachment arrangements, such as metal-plastic bonding from the molding operation, interference fit, heat bonding, adhesive, or ultrasonic welding, as seen in  FIG. 11 . 
         [0051]    The ammunition article  21  preferably also includes a base  45  attached to the second end  27  of the cartridge casing body  23 . One suitable material for the cartridge casing body  23  is a modified ZYTEL resin, available from E.I. DuPont De Nemours Co., a modified 612 nylon resin, modified to increase elastic response. In embodiments of the present invention wherein a molded cartridge casing body may be provided, a suitable cartridge casing body may also be made of a moldable material that forms part of the propellant pack, i.e., a moldable propellant, or otherwise is itself combustible or consumable by a propellant such as a powder ignition. The base  45  may be made of any suitable conventional material, for example, a metal material such as brass. According to one embodiment of the present invention, the base  45  is made of a plastic material, and is preferably molded out of a long fiber reinforced nylon material to provide great stiffness, high compressive strength, and minimal cold flow, although other well known materials may be used for the base. As desired or necessary, the base may be a metal base, such as a brass base, or a plastic material base, a ceramic base, a composite base, a combination of plastic, composite, or ceramic, or may incorporate the composite reinforced ceramic technology disclosed in U.S. patent application Ser. No. 08/590,621, which is expressly incorporated by reference. If desired or necessary, the base  45  and the cartridge casing body  23  can be made of the same material. For at least some applications, the cartridge casing body  23  is preferably somewhat more flexible than the base  45  to facilitate creation of a gas seal with the chamber, but fracture properties are preferably such as to facilitate breaking off of a flange  41 ′ (if provided) relatively cleanly from the rest of the cartridge casing body without causing other parts of the cartridge casing body to break off and follow the projectile  29  during firing. Preferably, the base  45  is sufficiently sturdy to be reusable, even when it may be necessary to replace the cartridge casing body  23  after each use. 
         [0052]    The base  45  is attached to the cartridge casing body  23  by any suitable attachment arrangement, or combination of attachment arrangements. As seen in  FIG. 12 , the base  45  may be attached to the cartridge casing body  23  by a suitable attachment arrangement  47 , such as by a mechanically interconnecting structure or otherwise. Suitable attachment arrangements  47  may include, for example, screw threads, a tongue and groove arrangement, flanges or pins and grooves, detent and detent receiving recesses, an interference fit, a heat bond, an adhesive, or an ultrasonic weld, or a combination of these attachment arrangements. 
         [0053]    As seen in  FIG. 4B , the ammunition article  21  preferably includes a propellant charge P inside the cartridge casing body  23 . A variety of propellant charge types are well known and, for purposes of the present application and except where otherwise indicated, can be considered to broadly include all suitable types of charges, such as those that are conventionally thought of as propellant charges and those that are conventionally considered to be explosive charges, such as black powder charges or charges such as PYRODEX, a smokeless black powder substitute available from Hodgdon Powder Co., Inc., Shawnee Mission, Kans. Depending upon the type of ammunition article  21 , the ammunition article may include some means for igniting the propellant, such as a primer  49  ( FIG. 4B ) for igniting the propellant, or an electronic ignition  49 ′ for igniting the propellant (shown schematically in  FIG. 4A ), or means for igniting the propellant may be partially or completely external to the ammunition article. 
         [0054]    As seen in  FIG. 13A , the cartridge casing body  23  is preferably made by molding plastic around at least the portion  31  of the projectile  29  to form the plastic cartridge casing body having the first end  25  to which the projectile is attached and a second end  27 . Numerous plastic molding techniques are well known and are suitable for use in connection with the present application. The plastic is preferably molded around a core pull  51  such that the core pull and the portion  31  of the projectile  29  define the interior volume  33  of the plastic cartridge casing body  23 . A leading end  52  of the core pull  51  preferably abuts against the base  40  of the projectile  29 . After molding, the core pull  51  is removed from the plastic cartridge casing body  23 . Preferably, the core pull  51  has a smaller diameter than the portion  31  of the projectile such that the interior volume  33  of the cartridge casing body  23  includes the first interior portion  35  defined by the portion of the projectile and a second interior portion  37  having a smaller diameter than the first interior portion and being separated from the first interior portion by the shoulder  39 . The shoulder  39  is preferably of sufficient size to prevent axial movement of the projectile  29  into the second interior portion  37 . 
         [0055]    If desired or necessary, one or more attachment arrangements above and beyond the metal-plastic bond developed upon molding the plastic of the plastic cartridge casing body  23  around the portion  31  of the projectile  29  may be provided. The attachment arrangement  41  can be provided by, for example, heat bonding the projectile to the cartridge casing body, by adhesive bonding of the projectile to the cartridge casing body, or ultrasonic welding of the cartridge casing body to the projectile. The attachment arrangement may be provided by providing one or more recesses  43  in the portion  31  of the projectile  29  such that, when the plastic is molded around the portion of the projectile, the plastic enters the recesses and forms what is referred to herein as a flange  41 ′ on the cartridge casing body  23 , the flange  41 ′ extending into the recess. 
         [0056]    As seen in  FIGS. 13A and 13B , the molding operation is preferably performed in a mold  53  (showing a half mold and not showing another half of the mold which is preferably symmetrical to the illustrated half mold). The mold  53  preferably includes a cavity  55  in which the core pull  51  is axially movable to a position in which the leading end of the core pull preferably abuts against the base  40  of the projectile  29 . As seen in  FIG. 13A , a front end  57  of the projectile  29  is preferably positioned against a mold element  59  corresponding in shape to the front end of the projectile, and which ensures proper axial positioning of the projectile relative to walls of the cavity  55 . The mold element  59  may be integral with the mold  53 , or may be a separate part that may be movable, as desired or necessary. An alternative form of mold  53 ″ is shown in  FIG. 13C , wherein a stationary or movable element  59 ″ is substituted for the mold element  59 , and receives a front end of the projectile for axial positioning of the projectile  29 , and separable mold halves close around a rear portion of the projectile to define, with the projectile and a pull  51 , walls of a cavity  55 ″ in which a plastic cartridge casing body is to be formed. 
         [0057]    Another form of mold  53 ′ is shown in  FIGS. 14A and 14B  and, instead of two identical or similar mold halves, such as are used in the embodiment of the method shown in  FIGS. 13A and 13B , as seen in  FIG. 14A , the mold  53 ′ preferably includes an end  53   a  having a portion  59 ′ in which the front end  57  of the projectile  29  is received and which positions the projectile relative to walls  55 ′ of another end  53   b  of the mold in which a core pull  51 ′ is provided. The core pull  51 ′ is preferably axially movable relative to the end  53   b . If desired or necessary, the mold end  53   b  may include two separable halves to facilitate removal of the cartridge casing body  23  and the projectile  29  after forming. 
         [0058]    Regardless of the mold type used, and as discussed with reference to  FIG. 13A , plastic is provided to the cavity  55  to fill voids between the walls of the cavity  55  and the walls of the portion  31  of the projectile, including any exposed portions of the base  40  of the projectile, and the core pull  51  to form the cartridge casing body  23 . If one or more recesses  43  are provided in the projectile  29 , corresponding flanges  41 ′ are formed when the plastic fills the recesses. Attachment arrangements  41  such as heat bonds, adhesive bonds, and ultrasonic welds may be provided while the projectile  29  and the cartridge casing body  23  reside in the cavity  55 , or after removal of the cartridge casing body and the projectile from the cavity, as desired or necessary. Techniques for providing attachment arrangements  41  are well known and will not be further described here. When the cartridge casing body  23  is molded, the core pull  51  is axially drawn from the second interior portion  37  of the cartridge casing body. 
         [0059]    As seen in  FIG. 15 , the propellant charge P, such as gunpowder or other propellant, is preferably provided inside of the cartridge casing body  23 , generally in the second interior portion  37  of the cartridge casing body, and the base  45  is preferably attached to the second end  27  of the cartridge casing body, preferably following removal of the cartridge casing body and the projectile  29  from the mold  53 . If provided, an ignition device such as a primer ( FIG. 4B ) or an electronic ignition ( FIG. 4A ) is also provided, or, depending upon the nature of the ignition device, partially provided. If desired or necessary, it is, of course, possible to construct a mold and core arrangement to permit providing the charge P and attachment of the base  45  and primer while the cartridge casing body  23  and the projectile  29  continue to reside in the mold  53 . 
         [0060]    The base  45  may be a metal, such as brass, base, or may be plastic, composite, ceramic, or a combination of materials. A plastic or composite base  45  is preferably molded separately from the molding operation in which the cartridge casing body  23  is molded, before attachment to the cartridge casing body. The base  45  may be attached to the cartridge casing body  23  by any suitable attachment arrangement technique, such as through a mechanical attachment wherein interconnecting components of the base and the cartridge casing body are fitted together, or by any other suitable technique or combination of techniques. The base  45  may, for example, be attached to the cartridge casing body  23  by an attachment arrangement involving the screwing together of threads on the base with threads on the cartridge casing body. The base  45  may be attached to the cartridge casing body  23  by an attachment arrangement technique involving connecting a tongue and groove arrangement between attachable portions of the base and the cartridge casing body. The base  45  may be attached to the cartridge casing body  23  by an attachment arrangement technique involving forming an interference fit between the cartridge casing body and the base. The base  45  may be attached to the cartridge casing body  23  by an attachment arrangement technique involving adhesive joining. The base  45  may be attached to the cartridge casing body  23  by an attachment arrangement technique involving heat bonding. The base  45  may be attached to the cartridge casing body  23  by an attachment arrangement technique involving ultrasonic welding. 
         [0061]    Another embodiment of an ammunition article  121  according to the present invention is shown in an exploded view in  FIG. 16  but, when assembled, can appear substantially the same as the ammunition article  21  illustrated in  FIGS. 1-3 . As seen in  FIG. 17 , the ammunition article  121  includes a cartridge casing body  123  having a first end  125  and a second end  127 . A projectile  129  is attached to the first end  125  of the cartridge casing body  123 . A base  131 , seen in  FIGS. 18A-19 , is preferably formed as a single piece of molded plastic, or from a ceramic, a composite, or a combination of plastic, composite, or ceramic, such as, for example, by starting with a ceramic liner  131   l  and molding a composite or plastic material  131   m  over the ceramic liner, as seen in  FIG. 18B . The base  131  may also incorporate the composite reinforced ceramic technology disclosed in U.S. patent application Ser. No. 08/590,621, which is hereby expressly incorporated by reference. As seen in  FIG. 17 , the base  131  is attached to the second end of the cartridge casing body. In this embodiment, the cartridge casing body  123  may be a plastic cartridge casing body, such as the plastic cartridge casing body described in connection with  FIGS. 1-15 , or a metallic cartridge casing body, such as a brass body in which a projectile is installed, as seen in  FIG. 20 , or which is for a blank cartridge, or a suitable ceramic, composite, or other desired material. The cartridge casing body  123  may also be made of a moldable material that forms part of the propellant pack, i.e., a moldable propellant, or otherwise is itself combustible or consumable by a propellant such as a powder ignition. 
         [0062]    A propellant charge is preferably provided inside the cartridge casing body  123  and, as seen in  FIG. 17 , a device for igniting the propellant, such as a primer  133  or an electronic ignition may be provided, or partially provided, for igniting the propellant. Although the base  131  is a plastic base, the base is preferably made of a sufficiently sturdy material to be reusable although the cartridge casing body  123  may be replaceable. The base  131  is attached to the cartridge casing body  123  by any suitable attachment arrangement  135 . The attachment arrangement  135  may, for example, be a mechanical attachment arrangement wherein portions of the base  131  and the cartridge casing body  123  interconnect with each other. Suitable attachment arrangements  135  include screw thread arrangements wherein the base  131  is attached to the cartridge casing body  123  by screw threads, tongue and groove arrangements, an interference fit the cartridge casing body, adhesive, a heat bond, and an ultrasonic weld. 
         [0063]    The ammunition article  121  is preferably made according to a method as seen in  FIG. 21  wherein plastic is molded in a mold  137  around one or more cores  139  to form the single piece, molded plastic base  131 . The mold  137  may have two, substantially symmetrical halves, as seen in  FIG. 21 , that separate in a direction transverse to a longitudinal axis of the base  131 , the mold may have two parts that separate in a direction of a longitudinal axis of the base, or the mold may have a single component, with the core  139  closing an end of the single component mold and one or both of the core and the single component mold being movable to permit removal of the base. If desired or necessary, the cartridge casing body or an ignition device or some component of an ammunition article may form part or all of a core around which the base  131  is molded. As seen in  FIGS. 16 and 17 , preferably after molding, the base  131  is attached to the second end  127  of the cartridge casing body  123  using a suitable attachment arrangement  135 . The cartridge casing body  123  may be a molded plastic cartridge casing body, such as the body described with reference to  FIGS. 1-15 , which is preferably formed in a separate operation from the molding of the base  131 , or a metallic cartridge casing body, such as the body shown in  FIG. 20 . Preferably, before attachment of the base  131  and the cartridge casing body  123 , a propellant is provided in the cartridge casing body. A device for igniting the propellant may be provided or partially provided, such as a primer  133  or an electronic ignition, and may be attached or partially attached to the base  131  depending upon the nature of the device. 
         [0064]    Another embodiment of an ammunition article  221  according to the present invention is shown in  FIG. 22 . The ammunition article  221  is particularly well-suited for use as a blank cartridge. The ammunition article  221  includes a molded plastic cartridge case body  223  having a closed front end  225  and a second end  227 . Although the ammunition article  221  is illustrated as having a convex front end  225 , it will be appreciated that the front end can be any shape desired or necessary, such as flat, convex, or whatever shape yields desired characteristics. 
         [0065]    As seen in  FIG. 23 , the ammunition article  221  is preferably molded in a mold  229  around a core pull  231 . The core pull  231  and the mold  229  are preferably shaped such that the closed front end  225  preferably includes walls that reduce in thickness toward an axial center  233  of the closed front end to facilitate causing the ammunition article to break at the tip and minimize the potential for portions of the wall becoming projectiles. Moreover, the closed front end  225  preferably includes at least one, preferably a plurality of stress concentrators  235  for causing preferential tearing of the closed front end at the stress concentrators such that, upon firing, the front end will tend to split open at the axial tip at the center  233  and permit expansion of a charge, preferably a charge consisting of an explosive charge, such as black powder or PYRODEX, a smokeless black powder substitute available from Hodgdon Powder Co., Inc., Shawnee Mission, Kans. If desired or necessary, another propellant charge may be used. 
         [0066]    As seen in  FIG. 24-26 , the core pull  231  preferably has raised portions  237  for forming the stress concentrators  235 . The raised portions  237  are preferably in the form of intersecting lines that intersect at the tip  239  of the core pull  231  such that the resulting shape of the stress concentrators  235  on the interior wall of the front portion  225  of the cartridge casing body  223  will be such that the cartridge casing body will split open along the stress concentrators at the center  233  and along the length of the stress concentrators, reducing the possibility of portions of the cartridge casing body becoming projectiles upon expansion of a powder charge. If desired or necessary, stress concentrators can be provided on an exterior surface of the cartridge casing body  223  in addition to or instead of the stress concentrators  235  on the interior surface of the front portion  225 , preferably by providing appropriately shaped raised portions on the mold  229 . 
         [0067]    As with the cartridge casing body  23 , a base  241  (shown in phantom in  FIG. 22 ) like the base  45  is preferably attached to the cartridge casing body  223  by one or more of the same attachment arrangements, and a propellant (not shown) and a powder charge ignition device (not shown) are preferably also provided. The base may be a reusable base, and the cartridge casing body  223  is preferably replaceable on the base. 
         [0068]    As seen in  FIGS. 23 and 27 , the cartridge casing body  223  is preferably formed by molding plastic around the core pull  231  to form the molded plastic cartridge case body  223  having a closed front end  225  and a second end  227 . The core pull  231  is removed from the cartridge casing body  223  after the plastic is molded around the core pull. The mold  229  is preferably a two-piece mold (one piece of which is shown in  FIG. 23 ) that separates along a plane extending through a longitudinal axis of the cartridge casing body, and at least one of the mold and the core pull  231  is movable relative to the other such that the core pull can be removed along the longitudinal axis of the cartridge casing body. 
         [0069]    Yet another embodiment of an ammunition article  321  is shown in an exploded view in  FIG. 28 . The ammunition article  321  includes a molded plastic cartridge case body  323 . The cartridge case body  323  includes a web  325  dividing an internal volume of the body to define a lower cavity  327  for receiving a propellant and an upper cavity  329  for receiving a projectile  331 . The web  325  includes an upwardly extending prong  333  for being received in a corresponding recess  335  in a base  337  of the projectile  331  to fasten the cartridge casing body  323  to the projectile. The prong  333  may be attached in the recess  335  by any suitable attachment arrangement and attachment technique, such as by an interference fit, by interlocking structures on the prong and the recess, by an adhesive, by heat bonding, and by ultrasonic welding. The cartridge casing body  323  may, of course, be molded around the projectile  331  in a manner similar to the manner in which the cartridge casing body  23  is molded around the projectile  29 , except that a core pull would not extend all the way to a base of the projectile. The prong  333  may be formed by causing plastic to enter the recess  333  during the molding operation. 
         [0070]    Alternatively, the cartridge casing body  323  may be formed in a separate molding operation and thereafter attached to the projectile  331  such that the prong  333  is caused to enter the recess  335 . A base (not shown) may be attached by a suitable attachment arrangement in the same way that the base  45  is attached to the cartridge casing body  23 , and a propellant charge (not shown) and a propellant ignition device (not shown) may be provided in the same was as with the ammunition article  21 . U.S. Pat. No. 5,033,386 and U.S. Pat. No. 5,151,555 disclose plastic cartridge cases having a web extending across a body of the cartridge cases and are hereby expressly incorporated by reference. 
         [0071]      FIG. 29  discloses yet another embodiment of an ammunition article  321 ′ including a plastic cartridge casing body  323 ′. The body  323 ′ is molded to conform with a bottom end  325 ′ of the projectile in which a recess  327 ′ is provided such that a protrusion  329 ′ is molded in the recess and, preferably, the walls of the body do not extend up the sides of the projectile. This embodiment of the ammunition article  321 ′ facilitates use of a combustible cartridge casing body  323 ′, such as where the cartridge casing body itself forms part of the propellant pack. Where the cartridge casing body  323 ′ is intended to be part of the propellant pack, the base is preferably adapted to expand during firing to form a gas seal. As desired or necessary, the base may be a metal base, such as a brass base, or a plastic material base, a ceramic base, a composite base, a combination of plastic, composite, or ceramic, or may incorporate the composite reinforced ceramic technology disclosed in U.S. patent application Ser. No. 08/590,621, which is expressly incorporated by reference. 
         [0072]    Yet another embodiment of an ammunition article  421  according to the present invention comprises a projectile  423  having cannelure contours  425  and a molded cartridge casing body  427  molded around at least a portion of the projectile such that a portion  429  of a wall  431  of the cartridge casing body follows the cannelure contours of the projectile. The portion  429  of the wall  431  preferably has a substantially constant thickness such that, where the projectile is recessed, the portion of the wall is also recessed. 
         [0073]    The foregoing embodiments of the present invention are all believed to be useful for use with all types of cartridges or blanks, regardless of shape. For example, in all of the embodiments, the cartridge casing body may be, for example, cylindrical, bottle-shaped, or have other suitable shapes as desired or necessary. 
         [0074]    While this invention has been illustrated and described in accordance with a preferred embodiment, it is recognized that variations and changes may be made therein without departing from the invention as set forth in the claims and equivalents thereof.

Technology Classification (CPC): 5