Patent Publication Number: US-11656063-B2

Title: Reduced-energy cartridge with exterior sealing member for fluted chamber

Description:
TECHNICAL FIELD 
     The following generally relates to a cartridge for a firearm and, more particularly, relates to a reduced-energy cartridge with an exterior sealing member for a firearm with a fluted chamber. 
     BACKGROUND 
     Firearm cartridges are available in a wide variety of configurations. Some are configured for blowback operation. Usually, in configurations that rely on blowback operation, the breech is not locked mechanically at the time of firing. Once open, the cartridge or cartridge case is ejected. 
     The cartridge should perform reliably during such operations. Specifically, the casing should be well-supported in the chamber during firing. As such, pressure in the chamber can be effectively applied for both driving the projectile out of the barrel and for recoiling the bolt assembly. 
     However, conventional cartridges suffer from various limitations and/or deficiencies. For example, the material of the casing may be relatively expensive and/or the material may be relatively heavy. Other materials may not possess needed characteristics (e.g., thermal expansion characteristics) for reliable operation. 
     Also, some cartridges may include features that intentionally limit energy and speed of the projectile. The features of these so-called reduced-energy cartridges may, however, offset the balance of pressures necessary for effectively projecting the projectile and ejecting the ignited cartridge due to blowback. 
     Moreover, some cartridges may be ill-suited for firearms with chambers that include surface features. For example, fluting in the chamber may negatively offset the balance of pressures necessary for blowback operation of some cartridges. 
     Accordingly, it is desirable to provide an improved cartridge, such as a reduced-energy cartridge for a firearm that reliably provides blowback operation, even in a fluted chamber. Furthermore, it is desirable to provide a cartridge with materials that are lower cost, lighter in weight, etc. as compared to standard materials. Moreover, it is desirable to provide a cartridge that robustly supports a projectile to bring it up to the desired speed and energy (including for reduced-energy configurations) and that also reliably ejects from the chamber in a blowback operation. Furthermore, other desirable features and characteristics of the various embodiments described herein will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and this background. 
     SUMMARY 
     A reduced-energy cartridge for a chamber of a firearm is disclosed. The cartridge includes a case and a sabot with a first end and a second end that are separated along a longitudinal axis. The first end is attached to the case to cooperatively define an internal combustion chamber with the case. The sabot is moveably attached to the case and supported for movement relative to the case from an unfired position to a fired position resulting from combustion within the combustion chamber. The second end extends from the case along the longitudinal axis in the unfired and fired positions. The cartridge further includes a sealing member that is provided on the second end of the sabot. The sealing member projects radially outward from the longitudinal axis and from the sabot. The sealing member defines a blowback boundary where the cartridge is configured to seal against an inner surface of the chamber of the firearm, wherein a forward area of the cartridge and a rear area of the cartridge is separated by the blowback boundary. The sealing member is configured for releasably sealing against the inner surface of the chamber to regulate pressure at the forward area resulting from combustion within the combustion chamber. 
     Furthermore, a method of manufacturing a reduced-energy cartridge for a chamber of a firearm is disclosed according to example embodiments. The method includes attaching a first end of a sabot to a case to cooperatively define an internal combustion chamber with the case, including moveably attaching the sabot to the case and supporting the sabot for movement relative to the case from an unfired position to a fired position. The sabot includes a second end that is separated from the first end along a longitudinal axis. The second end extends from the case along the longitudinal axis in the unfired and fired positions. The method also includes providing a sealing member on the second end of the sabot. The sealing member projects radially outward from the longitudinal axis and radially outward from the sabot. The sealing member defines a blowback boundary where the cartridge is configured to seal against an inner surface of the chamber of the firearm. A forward area of the cartridge and a rear area of the cartridge are separated by the blowback boundary. The sealing member is configured for releasably sealing against the inner surface of the chamber to regulate pressure at the forward area resulting from combustion within the combustion chamber. 
     Moreover, a reduced-energy cartridge for a fluted chamber of a firearm is disclosed according to example embodiments. The cartridge includes a case and a sabot. The sabot includes a first end and a second end that are separated along a longitudinal axis. The sabot includes a combustion passage extending longitudinally between the first end and the second end. The first end is attached to the case to cooperatively define an internal combustion chamber with the case. The first end is supported for movement relative to the case from an unfired position to a fired position resulting from combustion within the combustion chamber. The second end extends from the case along the longitudinal axis in the unfired and fired positions. The second end has a frustoconic datum taper. Also, the cartridge includes a sealing member that is provided on the second end. The sealing member projects radially outward from the longitudinal axis and radially outward from the sabot. The sealing member defines a blowback boundary where the cartridge is configured to seal against a fluted inner surface of the chamber of the firearm. A forward area of the cartridge and a rear area of the cartridge are separated by the blowback boundary. The sealing member is configured for releasably sealing against the fluted inner surface of the chamber to regulate pressure at the forward area resulting from combustion within the combustion chamber. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The various embodiments will hereinafter be described in conjunction with the following drawing figures, wherein like numerals denote like elements, and wherein: 
         FIG.  1    is an isometric view of a reduced-energy cartridge with a sealing member according to example embodiments of the present disclosure; 
         FIG.  2    is a longitudinal cross-sectional view of the cartridge of  FIG.  1    shown in an unfired position; 
         FIG.  3    is a longitudinal cross-sectional view of cartridge of  FIG.  1    shown in a chamber of a firearm and shown in a fired position; 
         FIG.  4    is a cross-sectional view of a portion of the cartridge and chamber indicated in  FIG.  3   ; 
         FIG.  5    is an isometric view of the reduced-energy cartridge with a sealing member according to additional example embodiments of the present disclosure; 
         FIG.  6    is an axial cross-section of the cartridge of  FIG.  5    shown within a chamber; 
         FIG.  7    is a longitudinal cross-sectional view of the reduced-energy cartridge according to additional example embodiments of the present disclosure; and 
         FIG.  8    is a longitudinal cross-sectional view of the reduced-energy cartridge according to additional example embodiments of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     The following Detailed Description is merely exemplary in nature and is not intended to limit the various embodiments or the application and uses thereof. Furthermore, there is no intention to be bound by any theory presented in the preceding background or the following detailed description. 
     Various embodiments contemplated herein relate to cartridges (e.g., reduced-energy cartridges) for firearms that are configured for blowback operation. In some embodiments, these cartridges may be used as training ammunition for firing relatively low-mass projectiles. Cartridges of the present disclosure may include one or more features that improve cycling of a weapon (the action of expelling spent cartridges (or casings) from a firearm and subsequently loading a fresh round into the firing chamber) while maintaining performance of the projectile (e.g., maintaining energy to the projectile and projectile speed to within predetermined limits). 
     Referring initially to  FIG.  1   , a cartridge  100  for a firearm is illustrated according to example embodiments of the present disclosure. The cartridge  100  may be of any suitable caliber. The cartridge  100  may also be configured in different ways for different firearms. It will be appreciated that the term “firearm” is used generally herein to mean any weapon suitable for firing the cartridge  100 , including, but not limited to, a handgun, long gun, rifle, shotgun, carbine, machine gun, submachine gun, etc. Also, the cartridge  100  may be configured for firearms, including but not limited to those that are single-shot, repeating-action, semi-automatic or select-fire/fully automatic. In some embodiments, for example, the cartridge  100  may be configured as a 7.62×51 mm NATO cartridge and for firearms that are configured for such cartridges. 
     Generally, the cartridge  100  may define a longitudinal axis  102  that extends between an aft end  104  and a forward end  106 . It will be appreciated that a forward direction is defined along the axis  102  from the aft end  104  toward the forward end  106 . On the contrary, a rearward direction is defined along the axis  102  from the forward end  106  toward the aft end  104 . 
     Also, the cartridge  100  may include a casing  111  and a projectile  114 , which is removably attached to the casing  111 . However, it will be appreciated that the cartridge  100  of the present disclosure may include the casing  111  (and propellant therein) and that the projectile  114  may be omitted (e.g., when the cartridge  100  is configured as a blank). 
     The casing  111  may include a case  110  and a sabot  112 . The case  110  may be disposed at the aft end  104 , and the projectile  114  may be disposed at the forward end  106 . The sabot  112  may be disposed longitudinally between the case  110  and the projectile  114 . The sabot  112  may be moveably attached (e.g., slidably attached) to the case  110 , and the sabot  112  may be removably attached to the projectile  114 . 
     As shown in  FIG.  2   , the case  110  may be cylindrical and hollow with one substantially closed end and one open end. The case  110  may include an end cap  115  at the aft end  104 . The end cap  115  may include a radially-projecting (flange-like) rim  116 . The end cap  115  may also include a primer cap opening  120  that is centered on the axis  102 . The case  110  may also include a hollow side wall  117  that is centered about the axis  102  and that projects from the end cap  115  along the axis  102 . As such, the side wall  117  and end cap  115  cooperatively define an internal cavity  118  of the case  110 . The side wall  117  may include a terminal end  123  with an outer diameter area that tapers downward in radius and an inner diameter area with an annular groove  127 . The case  110  may be made from an aluminum-based material (e.g., aluminum or an aluminum alloy) in some embodiments; however, it will be appreciated that the case  110  may be made out of another material without departing from the scope of the present disclosure. 
     The sabot  112  may be elongate and cylindrical with a first end  124  and a second end  126  that are separated along the axis  102 . Furthermore, the sabot  112  may include a central passage  147  that is centered on the axis  102  and that extends continuously through the sabot  112  from the first end  124  to the second end  126 . The sabot  112  may include a shaft portion  125  disposed forward of the first end  124  and having a smaller radius than the rest of the sabot  112 . The shaft portion  125  may slide within the terminal end of the case  110 . The sabot  112  may additionally include a central longitudinal portion  128  with an annular body  132  having a larger radius than the rest of the sabot  112  and a forward body  134  with a comparably smaller radius. The forward body  134  may be disposed closer to the forward end  106 , and the annular body  132  may be disposed closer to the aft end  104 . The sabot  112  may include a taper  136  that gradually transitions between the annular body  132  and the forward body  134 . Additionally, the sabot  112  may include a datum taper  138 . The datum taper  138  may taper gradually downward as the datum taper  138  extends longitudinally and transitions from the forward body  134  to the second end  126  of the sabot  112 . 
     The second end  126  may further include a geometrical groove  142 . The groove  142  may be annular in some embodiments, but the geometry of the groove  142  may be configured otherwise without departing from the scope of the present disclosure. The groove  142  may be disposed at a distance  189  from the datum taper  138 . In some embodiments, the groove  142  may be disposed forward relative to the datum taper  138  as shown in  FIG.  4   . In other embodiments, the groove  142  may be disposed rearward relative to the taper  138 . Moreover, in some embodiments, the groove  142  may be disposed on the taper  138 . 
     The sabot  112  may further include a longitudinally directed annular flange  140  that defines the terminal portion of the second end  126 . The flange  140  may receive the projectile  114  in some embodiments ( FIG.  2   ). 
     The sabot  112  may define a unitary, one-piece member. The sabot  112  may also be made from and/or include an aluminum-based material (e.g., aluminum or an aluminum alloy) in some embodiments. However, other materials may be used without departing from the scope of the present disclosure. 
     A sealing disc  145  may be included proximate the first end  124  of the sabot  112 . The sealing disc  145  may be fixedly attached to the first end  124 , and the sealing disc  145  and first end  124  may include interlocking features, such as corresponding undercut radial surfaces. The sealing disc  145  may include a choke aperture  150  that is centrally located and that is centered on the axis  102 . The choke aperture  150  extends through the sealing disc  145  to fluidly connect the combustion chamber  152  and the passage  147 . The choke aperture  150  may include an inlet directed toward the aft end  104 . The choke aperture  150  may also include an outlet that tapers outward as it extends toward the forward end  106 . It will be appreciated that the dimensions of the inlet, the taper of the outlet, and/or other characteristics of the choke aperture  150  may be selected and configured for managing and controlling combustion within the cartridge  100  and for metering the quantity of gases directed to the projectile to control its speed and metering the quantity of gases for recoiling the weapon. 
     The first end  124  of the sabot  112  (including the sealing disc  145 ) may be received in the case  110 . The sealing disc  145  may have an outer diameter disposed at an inner diameter of the case  110  to substantially seal thereto. The sealing disc  145 , the first end  124 , and the shaft portion  125  of the sabot  112  may be supported for sliding movement within the cavity  118  of the case  110  such that the case  110  and sabot  112  may move telescopingly relative to each other between an unfired position ( FIG.  2   ) and a fired position ( FIG.  3   ). In the unfired position, the terminal end  123  of the case  110  may be disposed adjacent the annular body  132  and the first end  124  may be retracted within the case  110  as represented in  FIG.  2   . Moving to the fired position represented in  FIG.  3   , the shaft portion  125  may extend, slide, and project out of the case  110 . 
     The first end  124  of the sabot  112  with the attached sealing disc  145  may cooperate with the case  110  to define an internal combustion chamber  152 . As the sabot  112  slides relative to the case  110 , the volume of the chamber  152  changes. The volume in the chamber  152  grows as the sabot  112  and case  110  move from the unfired position toward the fired position. 
     The cartridge  100  may further include a propellant charge  160  ( FIG.  2   ). The propellant charge  160  may include a propellant  162  (gunpowder or cordite) included in the chamber  152 . The propellant charge  160  may also include a primer  122  within the primer cap opening  120 . 
     During a firing sequence, the primer  122  may ignite the propellant  162  to telescopingly move the cartridge  100  from the unfired position ( FIG.  2   ) to the fired position ( FIG.  3   ). As represented in  FIG.  3   , the choke aperture  150  regulates and controls distribution of the pressure that builds through central passage  147  for driving the projectile  114  and bringing the projectile  114  up to velocity as it exits the barrel of the firearm. It will be understood that the telescoping movement of the sabot  112  and case  110  may reduce or limit energy for the projectile  114  as compared to a cartridge with a rigid or fixed casing. 
     The cartridge  100  may further include a sealing member  170 . In some embodiments, the sealing member  170  may be an independent part that is removably attached to another part discussed above. For example, as shown in  FIGS.  1 - 4   , the sealing member  170  may be a part that is removably attached to the sabot  112 . However other embodiments of the sealing member may be integrated into another part. For example, as shown in  FIGS.  5 - 6   , the sealing member may be part of the sabot. 
     As shown in the embodiments of  FIGS.  1 - 4   , the sealing member  170  may have a predetermined geometrical shape, such as an annular or toric shape; however, the sealing member  170  may have another shape without departing from the scope of the present disclosure (e.g., the shapes discussed below with reference to  FIGS.  5  and  6   ). The sealing member  170  may be configured for substantially sealing against an inner surface  180  of a chamber  182  of a firearm  184  as will be discussed with reference to  FIGS.  3  and  4   . The sealing member  170  may have a wide variety of configurations for sealing to the inner surface  180  during action of the firearm. The sealing member  170  may regulate pressures for driving the projectile  114  up to speed and for blowback self-ejection of the case  110  and sabot  112  from the chamber  182 . 
     It will be appreciated that the seal of the sealing member  170  against the inner surface  180  is a temporary seal created during blowback operation. The sealing member  170  provides a seal and gas flow obstruction, thereby creating a significant pressure gradient between a forward area  198  and a rear area  197  of the cartridge  100  ( FIGS.  3  and  4   ) as will be discussed in greater detail below. 
     The sealing member  170  may have one of a variety of geometrical shapes, such as an annular shape, a toric shape, a toroidal shape, etc. Thus, the sealing member  170  may extend continuously about the axis  102 . The sealing member  170  may be centered on the axis  102 . 
     The sealing member  170  may also have a solid cross section. For example, the sealing member  170  may have a solid, circular cross section in some embodiments. However, the sealing member  170  may have another cross sectional shape without departing from the scope of the present disclosure. The sealing member  170  may be constructed from a resilient material. For example, the sealing member  170  may be made from a resilient polymeric material such as nitrile rubber (i.e., Buna-n rubber); however, the sealing member  170  may be made of other materials without departing from the scope of the present disclosure. Accordingly, the sealing member  170  may resiliently flex to provide sealing. 
     The sealing member  170  may be received and disposed within the continuous, annular groove  142  of the sabot  112 . Accordingly, the sealing member  170  may be disposed in a forward direction and spaced apart slightly at a distance  189  from the frustoconic datum taper  138  with respect to the axis  102 . In other embodiments, the sealing member  170  may be disposed in a rearward direction from the datum taper  138 , or the sealing member  170  may be disposed on the datum taper  138  in further embodiments. 
     Also, the sealing member  170  may project outward radially from surrounding areas of the outer surface of the sabot  112 . As shown in  FIGS.  3  and  4   , an outer radius  190  of the sealing member  170  may be approximately the same or only slightly larger than an outer radius  192  of the second end  126  of the sabot  112 . Thus, the outer radius  190  may be slightly larger than that of the datum taper  138 . 
     As mentioned, the sealing member  170  may be operable and configured to seal against the inner surface  180  of the chamber  182 . More specifically, while the cartridge  100  is in the unfired position, the datum taper  138  may nest against an inversely corresponding tapered chamber surface  193  of the inner surface  180  while the sealing member  170  seals against a forward portion  183  of the inner surface  180  of the chamber  182 . The diameter of the forward portion  183  may remain substantially constant along its longitudinal length. 
     In some embodiments, the sealing member  170  may be useful for sealing against a surface feature included on the inner surface  180 . For example, in some embodiments, the inner surface  180  may be fluted (i.e., may include one or more flutes  194 ). The flutes  194  may be shallow grooves that extend primarily in the longitudinal direction along the axis  102 . In some embodiments, the flutes  194  may extend straight or tapered in all direction and substantially parallel to the axis  102 , and there may be a plurality of flutes spaced apart equally about the axis  102  in a circumferential direction. However, in additional embodiments, the flutes  194  may extend primarily along the axis  102  but also slightly helically about the axis  102 . 
     The flutes  194  may extend along the tapered chamber surface  193  and to the forward portion  183 . The sealing member  170  may seal against the uneven, fluted forward portion  183  as represented in  FIG.  3   . For example, the radial dimensions of the sealing member  170 , the resilient flexibility of the sealing member  170 , the position of the sealing member  170  relative to the datum taper  138 , and/or other characteristics of the sealing member  170  may allow the cartridge  100  to achieve the seal. The sealing member  170  may achieve the balance of pressures for driving the projectile  114  and for blowback of the empty cartridge (i.e., the case  110  and sabot  112  in the fired position). 
     Operation of the sealing member  170  will now be discussed in greater detail. Assuming the cartridge  100  is in the unfired position of  FIG.  2   . The cartridge  100  may begin cycling, and in some embodiments, may move from a magazine into the chamber  182 . A bolt assembly may apply a forward-directed force (represented by arrows  195  in  FIG.  3   ) on the end cap  115 , and the force  195  may be provided by a recoil spring of the bolt assembly in some embodiments. This force  195  may push and substantially seal the sealing member  170  against the fluted forward portion  183  of the inner surface  180 . As such, the sealing member  170  may define a blowback boundary  199  of the cartridge  100 . The blowback boundary  199  may be defined where the sealing member  170  abuts and seals against the inner surface  180 . As such, the forward area  198  of the cartridge  100  and the rear area  197  of the cartridge  100  are separated longitudinally by the blowback boundary  199 . It will be appreciated that the blowback boundary  199  may move relative to the inner surface  180  as the cartridge  100  and the sealing member  170  move from the unfired position to the fired position and as the pressures in the chamber  182  change. More specifically, the blowback boundary  199  may move rearward from the forward portion  183  of the inner surface  180  to the tapered chamber surface  193  and further rearward during blowback operations. 
     The propellant charge  160  may be ignited, generating gas pressure that pushes the projectile  114  out of the barrel. Some of the generated gas pressure in the forward area  198  (represented at  196  in  FIG.  4   ) pushes rearward on the sabot  112 . The pressure  196  pushes against the sealing member  170  and back against the sabot  112  and case  110  in the fired position ( FIGS.  3  and  4   ). The pressure  196 , therefore, pushes back the bolt carrier assembly, which recoils the firearm, and once the breech is open, the empty cartridge (i.e., the case  110  and sabot  112 ) eject. Furthermore, a fresh cartridge  100  (in the unfired position) may move into the chamber  182 , for example, from the magazine. 
     The sealing member  170  effectively seals against the inner surface  180  of the chamber  182 , even in embodiments where the inner surface  180  is fluted. Also, even in embodiments where the cartridge  100  is a reduced-energy cartridge  100  (i.e., where forces are relatively low), the sealing member  170  provides the proper balance of pressures for bringing the projectile  114  up to the desired speed and for blowback ejection of the empty cartridge. 
     In addition, embodiments may include a sabot  112  and a case  110  that have relatively low thermal expansion characteristics. For example, as mentioned, the sabot  112  and case  110  may be made of aluminum in some embodiments in order to reduce weight of the cartridge  100  and to reduce material costs. However, it will be appreciated that the sabot  112  and/or case  110  may be made from other materials (e.g., brass, steel, etc.) without departing from the scope of the present disclosure. 
     The sealing member  170  also provides manufacturing benefits. For example, because of the features discussed above, the cartridge  100  may be manufactured efficiently. 
     Referring now to  FIGS.  5  and  6   , the cartridge  200  is shown according to additional embodiments of the present disclosure. The cartridge  200  may be substantially similar to the embodiments discussed above except as noted. Components that correspond to those of  FIGS.  1 - 4    are indicated by corresponding reference numbers increased by 100. 
     The cartridge  200  may include a case  210 , a sabot  212 , and a projectile  214 . Furthermore, the cartridge  200  may include a sealing member  270 . The sealing member  270  may include a plurality of elongate rails  271  (i.e., ribs, spines, ridges, etc.). In some embodiments, there may be six rails  271 ; however, the cartridge  200  may have any number of rails  271  without departing from the scope of the present disclosure. The rails  271  may be attached to the sabot  212  and may extend longitudinally along the outer surface thereof. In some embodiments, the outer surface of the rails  271  may define a taper. In the illustrated embodiment, the rails  271  extend substantially parallel to the axis  202 . Also, the rails  271  may be spaced apart equally about the axis  202  in the circumferential direction. 
     In some embodiments, the rails  271  of the sealing member  270  may be integrally attached to the sabot  212  so as to define a unitary (i.e., one-piece) body. For example, the sabot  212  and rails  271  may be integrally attached to define a unitary polymeric body (i.e., a polymeric one-piece body). However, it will be appreciated that the body may be made out of different materials without departing from the scope of the present disclosure. 
     The sealing member  270  may also define intermediate surfaces  272  located circumferentially between neighboring rails  271 . The intermediate surfaces  272  may be substantially smooth and the rails  271  may project out radially therefrom. Furthermore, in some embodiments, the rails  271  and/or the intermediate surfaces  272  may extend to the datum taper  238 . The rails  271  and/or the intermediate surfaces  272  may additionally extend to the flange  240  of the sabot  212 . 
     As shown in  FIG.  6   , when the cartridge  200  is disposed in the chamber  282  of the firearm  284 , the rails  271  may be received within corresponding ones of the flutes  294 . The flutes  294  and the rails  271  may, thus, have inverse contour, shape, etc. and may have a male-to-female configuration. During firing, the rails  271  and the intermediate surfaces  272  may deform to thereby seal against the inner surface  280 . In some embodiments, the rails  271 , the intermediate surfaces  272 , and/or other portions of the sabot  212  may plastically (i.e., permanently) deform to create the temporary seal discussed above. As such, the projectile  214  may achieve the desired velocity and the spent cartridge  200  may be ejected in the blowback operation as discussed above. 
     Referring now to  FIG.  7   , the cartridge  300  is shown according to additional embodiments of the present disclosure. The cartridge  300  may be substantially similar to the embodiments discussed above except as noted. Components that correspond to those of  FIGS.  1 - 4    are indicated by corresponding reference numbers increased by 200. 
     The cartridge  300  may include a case  310  and a sabot  312 . The cartridge  300  may also include a sealing member  370 . The sealing member  370  may be an O-ring, similar to the sealing member  170  of  FIGS.  1 - 4   . The sabot  312  may include a pointed end. The cartridge  300  may function as discussed above as a reduced-energy cartridge. However, the cartridge  300  may be configured as a blank cartridge (with no projectile). 
     Referring now to  FIG.  8   , the cartridge  400  is shown according to additional embodiments of the present disclosure. The cartridge  400  may be substantially similar to the embodiments discussed above except as noted. Components that correspond to those of  FIGS.  1 - 4    are indicated by corresponding reference numbers increased by 300. 
     The cartridge  400  may include a case  410  and a sabot  412 . The cartridge  400  may also include a sealing member  470 . The sealing member  470  may include a plurality of elongate rails, similar to the sealing member  270  of  FIGS.  5  and  6   . The sabot  412  may include a pointed end. The cartridge  400  may function as discussed above as a reduced-energy cartridge. However, the cartridge  400  may be configured as a blank cartridge (with no projectile). 
     While at least one exemplary embodiment has been presented in the foregoing detailed description of the disclosure, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the disclosure in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing an exemplary embodiment of the disclosure. It being understood that various changes may be made in the function and arrangement of elements described in an exemplary embodiment without departing from the scope of the disclosure as set forth in the appended claims.