Patent Publication Number: US-2023152057-A1

Title: Firearm shell casing

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 16/783,024, filed Feb. 5, 2020, which claims priority to and the benefit of U.S. Provisional Patent Application No. 62/803,872, filed on Feb. 11, 2019. The disclosure of the above application is incorporated herein by reference. 
    
    
     FIELD 
     The present disclosure relates to firearms and various accessories that improve the performance and operation of such firearms. 
     BACKGROUND 
     The statements in this section merely provide background information related to the present disclosure and may not constitute prior art. 
     Rail systems are strips of metal or plastic attached to a firearm to allow the ready attachment of various accessories, such as scopes, lights, hand grips, among others. Often the rail system interferes with the ejection of spent cartridges. This ejection interference may be caused by installation errors or design deficiencies. Ejection interference can cause many issues including malfunction of the firearm and cartridge impacts to the operator. 
     Customized ammunition generally involves a customized cartridge size or a customized projectile diameter. One issue with custom ammunition is that the ammunition is difficult to acquire because the ammunition is not mass-produced. The lack of mass-produced ammunition increases the cost of the ammunition and reduces the ability to sell the firearm that uses the ammunition. 
     During normal operation of a firearm (e.g. firearm discharge), significant amounts of flash (light), heat, noise (acoustics), and pollutants (e.g. spent gunpowder) are produced. It is desirable to reduce the flash, heat, and noise to improve the concealment of the firearm operator. Various sound reducing devices are employed to reduce noise levels. Unfortunately, these devices often increase the firearm barrel temperature, decrease shot accuracy, increase firearm weight, increase firearm blowback, increase manufacturing complexity, alter firearm recoil behavior, increase the time between successive shots on target. 
     The present disclosure addresses the issues of ejection interference, mass production of customized ammunition, and firearm discharge, among other issues related firearm operation. 
     SUMMARY 
     This section provides a general summary of the disclosure and is not a comprehensive disclosure of its full scope or all of its features. 
     In one form, a dual use shell casing for use in a 9 mm firearm and for use in 9 mm magazines includes an upper portion, a lower portion, an internal cavity extending between the upper portion and the lower portion, the internal cavity configured to receive gunpowder and a projectile, and a tapered shoulder disposed at the upper portion and transitioning into a reduced diameter neck portion, the reduced diameter neck portion having an inner diameter equal to 0.313 inches, wherein the tapered shoulder is configured to abut an internal shoulder within a barrel chamber of the 9 mm firearm. 
     In variations of the dual use shell casing, which may be implemented individually or in combination: the tapered shoulder is configured to regulate a depth to which the dual use shell casing slides into the barrel chamber of the 9 mm firearm by abutting a barrel chamber seat within the barrel chamber of the 9 mm firearm while the reduced diameter neck portion extends into a bore of the barrel chamber; the tapered shoulder defines an axial length, and the depth to which the dual use shell casing slides into the barrel chamber is determined based on the axial length of the tapered shoulder; further including a primer pocket and a flash hole connecting the primer pocket to the internal cavity; wherein the tapered shoulder defines an acute angle relative to a central axis of the shell casing; wherein a wall thickness of the lower portion is greater than a wall thickness of the upper portion. 
     In another form, a dual use cartridge for use in a 9 mm firearm and for use in 9 mm magazines includes a tapered shell casing including an upper portion, a lower portion, an internal cavity extending between the upper portion and the lower portion, the internal cavity configured to receive gunpowder and a projectile, and a tapered shoulder disposed at the upper portion and transitioning into a reduced diameter neck portion, the reduced diameter neck portion having an inner diameter equal to 0.313 inches, a projectile disposed within the internal cavity at the reduced diameter neck portion and secured therein, and gunpowder disposed within the internal cavity below the projectile, wherein the tapered shoulder is configured to abut an internal shoulder within a barrel chamber of the 9 mm firearm. 
     In variations of the dual use cartridge, which may be implemented individually or in combination: the tapered shell casing shoulder is configured to regulate a depth to which the tapered shell casing slides into the barrel chamber of the 9 mm firearm by abutting a barrel chamber seat within the barrel chamber of the 9 mm firearm while the reduced diameter neck portion extends into a bore of the barrel chamber; the tapered shoulder defines an axial length, and the depth to which the shell casing slides into the barrel chamber is determined based on the axial length of the tapered shoulder; the lower portion defines a primer pocket; further including primer compound disposed in the primer pocket; further including a primer cup configured to seal the primer compound in the primer pocket; the lower portion includes a shell casing rim; the gunpowder and the projectile define a gap therebetween; the tapered shoulder defines an acute angle relative to a central axis of the shell casing; a diameter of the projectile is smaller than a diameter of the lower portion; a wall thickness of the lower portion is greater than a wall thickness of the upper portion. 
     In another form, a dual use cartridge configured for use with a 9 mm firearm and for use in 9 mm magazines includes a tapered shell casing comprising an upper portion, a lower portion, an internal cavity extending between the upper portion and the lower portion and configured to receive gunpowder and a projectile, a tapered shoulder disposed at the upper portion and transitioning to a reduced diameter neck portion, a primer pocket, and a flash hole connecting the primer pocket to the internal cavity, a projectile disposed within the internal cavity at the reduced diameter neck portion and secured therein, gunpowder disposed within the internal cavity below the projectile, a primer compound disposed in the primer pocket, and a primer cup configured to seal the primer compound in the primer pocket, wherein the reduced diameter neck portion has an inner diameter equal to 0.313 inches, and wherein the tapered shell casing shoulder is configured to abut an internal shoulder within a barrel chamber of the 9 mm firearm. 
     In variations of the dual use cartridge, which may be implemented individually or in combination: the tapered shoulder is configured to regulate a depth to which the tapered shell casing slides into the barrel chamber of the 9 mm firearm by abutting a barrel chamber seat within the barrel chamber of the 9 mm firearm while the reduced diameter neck portion extends into a bore of the barrel chamber; the tapered shoulder defines an axial length, and the depth to which the shell casing slides into the barrel chamber is determined based on the axial length of the tapered shoulder. 
     Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. 
    
    
     
       DRAWINGS 
       In order that the disclosure may be well understood, there will now be described various forms thereof, given by way of example, reference being made to the accompanying drawings, in which: 
         FIG.  1 A  is a side view of a commercially available firearm cartridge; 
         FIG.  1 B  is a cross-sectional side view, taken along line  1 B- 1 B of  FIG.  1 A , of the commercially available firearm cartridge; 
         FIG.  2 A  is a side view and illustrates an exemplary shouldered cartridge, according to the teachings of the present disclosure; 
         FIG.  2 B  is a cross-sectional side view, taken along line  2 B- 2 B of  FIG.  2 A , of the shouldered cartridge, according to the teachings of the present disclosure; 
         FIG.  2 C  is an exploded view of the shouldered cartridge of  FIG.  2 B , according to the teachings of the present disclosure; 
         FIG.  2 D  is a perspective bottom view of the shouldered cartridge of  FIG.  2 A , according to the teachings of the present disclosure; 
         FIG.  3 A  is a cross-sectional side view of a commercially available firearm barrel; 
         FIG.  3 B  is a view of the firearm barrel of  FIG.  3 A  with the commercially available firearm cartridge of  FIG.  1 A ; 
         FIG.  3 C  is a view of the firearm barrel of  FIG.  3 A  with the shouldered cartridge of  FIG.  2 A , according to the teachings of the present disclosure; and 
         FIG.  3 D  is a cross-sectional side view and illustrates an exemplary firearm barrel with the shouldered cartridge of  FIG.  2 A , according to the teachings of the present disclosure. 
     
    
    
     The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way. 
     DETAILED DESCRIPTION 
     The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features. 
     Referring to  FIG.  1 A and  1 B , a commercially available cartridge  150  comprises at least one of a projectile  152 , a shell casing  154 , a shell casing rim  156 , flash hole  158 , a gunpowder cavity, gunpowder  160 , a primer pocket  162 , a primer cup  164 , a primer compound  166 , and a gunpowder-projectile gap  168 . The shell casing  154  is a cone that slightly tapers from the shell casing rim  156  to the projectile  152 . The degree of taper depends on the cartridge however, a 9 mm diameter shell casing tapers approximately 0.5 mm per 19 mm of length (+/−1 mm). The gunpowder cavity is adjacent to the flash hole  158 ; the flash hole  158  is adjacent to the primer pocket  162 ; and the gunpowder cavity and the primer pocket  162  on opposing ends of the flash hole  158 . 
     The gunpowder cavity contains the gunpowder  160 , the gunpowder-projectile gap  168 , and the projectile  152 . The projectile  152  is partially contained within the gunpowder cavity, and the gunpowder cavity is sealed by compressing the shell casing  154  around the projectile  152 . The primer pocket  162  contains the primer compound  166  and the primer cup  164 , and the primer cup  164  seals the primer pocket  162 . 
     Now referring to  FIGS.  2 A and  2 B , a shouldered cartridge  170  (also referred to as a “dual use cartridge”) according to the present disclosure is provided. The shouldered cartridge  170  comprises a projectile  172 , a tapered shell casing  174  (also referred to as a “dual use casing”) generally defining an upper portion  175  and a lower portion  177 , and a tapered shell casing shoulder  176 . The shouldered cartridge  170  in this form further includes the shell casing rim  156 , the flash hole  158 , gunpowder  160 ′, primer pocket  162 , primer cup  164 , primer compound  166 , a gunpowder-projectile gap  168 ′, and combinations thereof. 
     Referring to  FIGS.  2 C and  2 D , the tapered shell casing  174  includes the tapered shell casing shoulder  176 , a wide-tapered diameter  178 , and a narrow diameter  180  (reduced diameter neck portion). The wide-tapered diameter  178  extends from the shell casing rim  156  to the narrow diameter  180 , and the tapered shell casing shoulder  176  transitions between the two diameters. The tapered shell casing shoulder  176  regulates the depth to which the cartridge slides into the barrel chamber. The wide-tapered diameter  178 , the tapered shell casing shoulder  176 , and the narrow diameter  180  are outer diameters of the tapered shell casing  74 . In general, the length of the tapered shell casing  174  is longer than the standard casing by between 1 and 25.4 mm, in 0.5 mm increments, with a desired length of 4 mm longer. However, for certain applications, cartridges with more than 25.4 mm of additional shell casing will be desired. There is necessary variation due to the intended muzzle velocity and that a 12.7 mm cartridge will have a different additional length than a 5.56 mm cartridge. A wall thickness of the tapered shell casing  174  varies along its length such that the wall thickness is greater at the lower portion  177  than at the upper portion  175 . 
     Referring to  FIG.  3 A , a commercially available firearm barrel  190  is provided. The commercially available firearm barrel  190  comprises a bore  192  and a barrel chamber  194  with a barrel chamber seat  196  between them. The bore  192  extends from the barrel chamber seat  196  to the end of the firearm barrel (not shown). 
     Referring now to  FIG.  3 B , commercially available cartridge  150  is loaded within barrel chamber  194 , with commercially available cartridge  150  coupling to the barrel chamber seat  196  and bore  192  forming a seal that allows gas pressure from firearm discharge to propel the projectile  152  properly (i.e., accurately) out of bore  192 . The gas pressure propels the projectile  152  longitudinally and distally out of bore  192 . 
     When shell casing  154  is loaded with a projectile (wildcat projectile) other than the projectile  152 , a wildcat cartridge (not shown) is formed. The seal between the wildcat cartridge and the commercially available firearm barrel  190  is insufficient to direct the majority of the discharge pressure to propel the wildcat projectile longitudinally and distally out of the commercially available firearm barrel  190 . An insufficient seal is formed between the shell casing  154 , barrel chamber  194 , and barrel chamber seat  196 ; thus, the majority of the discharge pressure is directed distally from the barrel chamber  194  towards the bore  192 . Unfortunately, the insufficient seal also allows pressure to escape around the projectile, directed transverse to bore  192 . The transverse discharge pressure creates excess Hoop stresses often causing shell casing  154  to rupture, often damaging at least one of the firearm, the operator, and the surrounding area also known as a misfire or malfunction. The projectile can also become jammed within bore  192  or the firing mechanism. Further, the majority of wildcat cartridges will not cycle the firearm action sufficiently to load another round. 
     Now referring to  FIG.  3 C , shouldered cartridge  170  is loaded within barrel chamber  194  and the tapered shell casing shoulder  176 , narrow diameter  180 , and bore  192  form a seal with barrel chamber seat  196  sufficient to propel projectile  172  out of bore  192 , the seal is also sufficient to inhibit the transverse pressure and reducing the risk of malfunction. Further, the risk of damage to at least one of the firearm, the operator, and the surrounding area is also reduced. Note the accuracy may be reduced do to the lower pressure and engagement between the projectile  172  and bore rifling (not shown). 
     However, referring to  FIG.  3 D  the desired configuration of the present disclosure, commercially available firearm barrel  190 ′ is provided. Commercially available firearm barrel  190 ′ comprises a bore  192 ′, a barrel chamber  194 ′, and a barrel chamber seat  196 ′. The barrel chamber seat  196 ′ has an internal tapered shell casing shoulder (also referred to as an “internal shoulder”) that seals to the tapered shell casing shoulder of shouldered cartridge  170 . The internal shoulder defines an axial length, and the depth to which the dual use shell casing slides into the barrel chamber is determined based on the axial length of the tapered shoulder. The barrel chamber seat  196 ′ and bore  192 ′ are configured to properly form a seal sufficient for reliable accuracy; effectively, this is a wildcat cartridge in a firearm configured for the wildcat cartridge. 
     In one form of the present disclosure, the shouldered cartridge  170  is modified for use with a 9 mm receiver (not shown), with the desire being that the barrel is customized to accurately seat a 0.313 caliber projectile  172  instead of a 9 mm (0.36 inch) diameter projectile  152 . The projectile has a 0.313 inch (7.95 mm) outer diameter (O.D.) and would be referred to as a 0.313 caliber projectile. The tapered shell casing  174  is approximately 0.9 inches (22.9 mm) long. The tapered shell casing shoulder  176  has an included angle of 60 degrees (+/−1 degree, with +/−0.5 degrees desired) relative to a central axis of the tapered shell casing  174  between the wide-tapered diameter  178  and the narrow diameter  180 . In another form, the included angle is a different acute angle relative to the central axis of the tapered shell casing  174 . The wide-tapered diameter  178  has a 0.41-inch (10.5 mm) O.D. Where all diameters and lengths are subject to commercial manufacturing tolerances of +/−0.04 inches (1 mm) with a desired tolerance of +/−0.02 inches (0.5 mm). Enabling the 9 mm firearm to use 0.313-inch diameter projectiles. 
     In at least one form of the present disclosure a tapered shell casing  174  for use in a 9 mm firearm and for use in 9 mm magazines is provided. The shouldered cartridge  170  comprises an internal cavity for receiving a projectile  172  and defining a tapered shell casing shoulder  176  transitioning into a narrow diameter  180  (reduced diameter neck portion) having an internal diameter from 0.313 inches (7.95 mm), wherein the tapered shell casing shoulder  176  is configured to abut an internal shoulder (the barrel chamber seat  196 ′ in this form) within a chamber  194 ′ of the 9 mm firearm. 
     In yet another form of the present disclosure, a shouldered cartridge  170  for use in a 9 mm firearm and for use in 9 mm magazines is provided. The shouldered cartridge  170  comprises a tapered shell casing comprising a cavity and defining a tapered shell casing shoulder  176  transitioning into a narrow diameter  180  having an internal diameter from 0.313 inches (7.95 mm), a projectile  172  disposed within the cavity and secured therein by the narrow diameter  180 , where gunpowder  160 ′ is disposed within the cavity below the projectile  172 , enabling the 9 mm firearm to use 0.313-inch (7.95 mm) diameter projectiles  72 . 
     Although the terms first, second, third, among others may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections, should not be limited by these terms. These terms may be only used to distinguish one element, component, region, layer and/or section, from another element, component, region, layer and/or section. Terms such as “first,” “second,” and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer or section, could be termed a second element, component, region, layer or section without departing from the teachings of the example forms. Furthermore, an element, component, region, layer or section may be termed a “second” element, component, region, layer or section, without the need for an element, component, region, layer or section termed a “first” element, component, region, layer or section. 
     Spacially relative terms, such as “inner,” “outer,” “below,” “lower,” “upper,” and the like, may be used herein for ease of description to describe one element or feature&#39;s relationship to another element(s) or feature(s) as illustrated in the figures. Spatially relative terms may be intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “below” other elements or features would then be oriented “above” the other elements or features. Thus, the example term “below” can encompass both an orientation of above or below. The device may be otherwise oriented (rotated  90  degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly. 
     Unless otherwise expressly indicated herein, all numerical values indicating mechanical/thermal properties, compositional percentages, dimensions and/or tolerances, or other characteristics are to be understood as modified by the word “about” or “approximately” in describing the scope of the present disclosure. This modification is desired for various reasons including industrial practice, material, manufacturing, and assembly tolerances, and testing capability. 
     As used herein, the phrase at least one of A, B, and C should be construed to mean a logical (A OR B OR C), using a non-exclusive logical OR, and should not be construed to mean “at least one of A, at least one of B, and at least one of C.” 
     The description of the disclosure is merely exemplary in nature and, thus, variations that do not depart from the substance of the disclosure are intended to be within the scope of the disclosure. Such variations are not to be regarded as a departure from the spirit and scope of the disclosure.