# Patent

## Title
Shotshell type ammunition, firearms for firing such shotshell type ammunition, and methods of manufacturing such shotshell type ammunition

## Abstract

Shotshell type ammunition includes a hull, a sabot disposed within the hull, and at least one projectile disposed within the sabot. The hull has a rimless first end that includes a primer for firing the ammunition. The hull also has a seat surface for seating the hull against a complementary seat surface in a firing chamber of a firearm. The seat surface is located a distance from an outer end surface of the hull at the rimless first end. The hull further includes an outer cylindrical side surface extending from the rimless first end of the hull to the seat surface of the hull. Methods of fabricating such ammunition include forming such a hull, providing one or more projectiles within a sabot, and disposing the sabot with the one or more projectiles therein at least partially into the hull. Shotgun type firearms are configured for firing such ammunition.

## Background
CROSS-REFERENCE TO RELATED APPLICATION
This application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/527,942, filed Aug. 26, 2011 and entitled “Rimless Shotshell,” which is incorporated herein in its entirety by this reference.


TECHNICAL FIELD
The present disclosure relates to shotshell type ammunition for shotgun type firearms, to shotgun type firearms configured for firing shotshell type ammunition, and to methods of manufacturing such shotshell type ammunition.
BACKGROUND
Conventional shotshell ammunition for firing from a shotgun has a hull that includes a metal cup-shaped structure defining a closed firing end of the ammunition, and a cylindrical portion that extends from the metal-cup shaped structure. A primer is provided at the firing end of the ammunition in an aperture extending through the cup-shaped structure. Gun powder is disposed within the hull within the metal cup-shaped structure and adjacent the primer. One or more projectiles are disposed within a sabot, and the sabot is disposed within the hull adjacent the gun powder such that the gun powder is disposed in a space between the metal cup-shaped structure of the hull and the sabot with the projectile therein. As used herein, the term “sabot” means a structure in which a projectile is carried through a barrel of a firearm and which separates from the projectile upon exiting the barrel of the firearm. The projectile may include a plurality of generally spherical rounded pellets, which are often referred to as the “shot” of the ammunition. The cylindrical portion of the hull is typically formed of plastic, and an end of the plastic cylindrical portion of the hull opposite the metal cup-shaped structure is mechanically deformed (by rolling, folding, etc.) and crimped to close the end of the ammunition opposite the firing end of the ammunition from which the sabot (and the one or more projectiles carried therein) exits the hull upon firing of the ammunition.
In conventional shotshell ammunition, the cylindrical portion of the hull has a maximum outer diameter that is smaller than a maximum outer diameter of the metal cup-shaped structure defining the closed firing end of the ammunition. Thus, the cup-shaped structure includes or defines a rim that projects outwardly in the radial direction beyond the outer surface of the cylindrical portion of the hull, and, in some previously known ammunition, a portion of the metal-cup-shaped structure having a reduced outer diameter. Conventional shotguns include a seat surface that is configured to abut against the metal rim at the firing end of the ammunition so as to prevent longitudinal forward movement of the hull within the shotgun when the shotshell type ammunition is fired from the shotgun.
BRIEF SUMMARY
This summary is provided to introduce a selection of concepts in a simplified form. These concepts are described in further detail in the detailed description of example embodiments of the disclosure below. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.
In some embodiments, the present disclosure includes shotshell type ammunition. The shotshell type ammunition includes a hull, a sabot disposed within the hull, and at least one projectile disposed within the sabot. The hull has a rimless first end that includes a primer for firing the ammunition. The hull has an opposing second end from which the at least one projectile may be ejected out from the hull upon firing the ammunition. The hull also has a seat surface for seating the hull against a complementary seat surface in a firing chamber of a firearm. The seat surface is located a distance from an outer end surface of the hull at the rimless first end. The hull further includes an outer cylindrical side surface extending from the rimless first end of the hull to the seat surface of the hull.
The present disclosure further includes shotgun type firearms configured to fire shotshell type ammunition as described herein. For example, in some embodiments, the present disclosure includes a shotgun type firearm having a firing chamber sized and configured to fire such shotshell type ammunition. The firearm includes a generally cylindrical inner surface extending through a headspace within the firing chamber. The generally cylindrical inner surface may have a length of at least about 0.318 centimeters (about 1⁄8 of an inch). The firearm further includes a seat surface within the firing chamber, which seat surface is configured to abut against a complementary seat surface of a hull of a shotshell type ammunition to be fired from the firearm and to prevent longitudinal forward movement of the hull within the firearm when the shotshell type ammunition is fired from the firearm.
In yet further embodiments, the present disclosure includes methods of manufacturing shotshell type ammunition as described herein. For example, a hull may be formed that has a rimless first end, and an opposing second end from which a projectile may be ejected out from the hull upon firing the ammunition. The hull also may be formed to have a seat surface for seating the hull against a complementary seat surface in a firing chamber of a firearm. The seat surface of the hull may be located a distance from an outer end surface of the hull at the rimless first end. The hull also may be formed to include an outer cylindrical side surface extending from the rimless first end of the hull to the seat surface of the hull. After forming the hull, a primer for firing the ammunition may be provided at the rimless first end of the hull. At least one projectile may be provided within a sabot, and the sabot may be inserted at least partially into the hull.



BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a longitudinal side view of an embodiment of shotshell type ammunition of the present disclosure.
FIG. 2 is a longitudinal cross-sectional side view of the shotshell type ammunition of FIG. 1.
FIG. 3 is a longitudinal cross-sectional side view of another embodiment of shotshell type ammunition of the present disclosure similar to that of FIGS. 1 and 2.
FIG. 4 is a longitudinal side view of another embodiment of shotshell type ammunition of the present disclosure.
FIG. 5 is a longitudinal cross-sectional side view of the shotshell type ammunition of FIG. 4.
FIG. 6 is a longitudinal cross-sectional side view of another embodiment of shotshell type ammunition of the present disclosure similar to that of FIGS. 4 and 5.
FIG. 7 is a side view of an embodiment of a shotgun type firearm of the present disclosure configured to fire shotshell type ammunition, such as that shown in FIGS. 1 through 6.
FIG. 8 is a cross-sectional view of a magazine of the firearm of FIG. 7 loaded with shotshell type ammunition as described herein.
FIG. 9 is a top view of the loaded magazine of FIG. 8.
FIG. 10 is a partial cross-sectional side view of the shotgun type firearm of FIG. 7 illustrating a loaded magazine like that of FIGS. 8 and 9 attached to the firearm, and a shotshell type ammunition being moved from the magazine and into a firing chamber of the firearm.
FIG. 11 is a partial cross-sectional side view like that of FIG. 10 illustrating a shotshell type ammunition fully loaded in the firing chamber of the firearm.
FIG. 12 is a partial cross-sectional side view illustrating a shotshell type ammunition fully loaded in the firing chamber of the firearm.
FIG. 13 is a partial cross-sectional side view like that of FIG. 12 illustrating a sabot carrying projectiles of the shotshell type ammunition moving through a barrel of the firearm after firing the shotshell type ammunition.
FIG. 14 is a partial cross-sectional side view like those of FIGS. 12 and 13 and illustrates the sabot opening and releasing the projectiles carried therein upon exiting the barrel of the firearm.
FIG. 15 is a side view illustrating a stack of shotshell type ammunition of a previously known configuration.
FIG. 16 is a side view illustrating a stack of shotshell type ammunition as described herein.



DETAILED DESCRIPTION
The illustrations presented herein are not meant to be actual views of any particular ammunition round, firearm, or component thereof, but are merely idealized representations that are used to describe embodiments of the disclosure.
FIGS. 1 and 2 illustrate an embodiment of a shotshell type ammunition 100 of the present disclosure. The shotshell type ammunition 100 includes a hull 102, gun powder 122 (FIG. 2) disposed within the hull 102, a sabot 118 (FIG. 2) disposed within the hull 102, and at least one projectile 120 (FIG. 2) disposed within the sabot 118.
The hull 102 has a rimless first end 104, an opposing second end 110, and a seat surface 112 for seating the hull 102 against a complementary seat surface in a firing chamber of a firearm. The seat surface 112 may be located a distance from an outer end surface 114 of the hull 102 at the rimless first end 104. An outer cylindrical side surface 106 may extend from the rimless first end 104 of the hull 102 to the seat surface 112 of the hull 102. The outer cylindrical side surface 106, the outer end surface 114, and the seat surface 112 may define what is referred to in the art as the “head space” of the shotshell type ammunition 100. The seat surface may be sized and configured to abut against a complementary seat surface in a firing chamber of a firearm, as described in further detail herein below, and may be used for ensuring precise and accurate positioning of the shotshell type ammunition 100 within the firing chamber of a firearm.
The hull 102 may comprise, for example, a metal or a polymer such as a plastic material. In some embodiments, a portion of the hull 102 may comprise a metal, and another portion of the hull 102 may comprise a polymer such as a plastic. For example, the rimless first end 104 of the hull 102 and a portion of the hull 102 comprising the outer cylindrical side surface 106 of the hull 102 may comprise a metal, and a portion of the hull 102 between the seat surface 112 and the second end 110 of the hull may comprise a polymer, such as a plastic material.
The shotshell type ammunition 100 may include a groove 113 extending into the hull 102 on a lateral side of the hull 102 proximate the rimless first end 104 of the hull 102. The groove 113 may be located and configured for use by a mechanism of a firearm to eject the shotshell type ammunition 100 out from the firearm after firing the shotshell type ammunition 100.
As shown in FIG. 2, the rimless first end 104 of the hull 102 may include a primer 124 for firing the ammunition 100. When struck by a firing pin of a shotgun type firearm, the primer 124 may ignite the gunpowder 122 within the hull 102, which in turn may eject the sabot 118 (with the at least one projectile 120 carried therein) out from the second end 110 of the hull 102.
The at least one projectile 120 disposed within the sabot 118 shown in FIG. 2 may be any of a number of different types of projectiles. Further, the at least one projectile may comprise one projectile, or more than one projectile. Thus, as a non-limiting example, the at least one projectile may comprise a plurality of rounded pellets, which are often referred to in the art as “shot.” In other embodiments, however, at least one projectile may comprise a metal slug, for example. In yet further embodiments, the at least one projectile may comprise a non-lethal or less-lethal projectile, such as one or more rubber masses, a bean bag, etc. In yet further embodiments, the at least one projectile may include an electronic device that is operational after it has been fired from a firearm, such as an electronic audio transmitter device configured to detect audible sound in the vicinity of the devices and to wirelessly transmit electronic signals carrying the detected audible sounds.
The opposing second end 110 of the hull 102 may be closed using any appropriate technique, including, folding and/or crimping an end of the hull 102.
The seat surface 112 may be located a distance L from the outer end surface 114 of the hull 102 so as to define the outer cylindrical side surface 106. In some embodiments, the distance L may be at least about 0.318 centimeters (about 1⁄8 of an inch), at least about 0.635 centimeters (about 1⁄4 of an inch), at least about 1.270 centimeters (about 1⁄2 of an inch), or even at least about 2.540 centimeters (about 1 inch).
The outer cylindrical side surface 106 of the hull 102 may define a maximum diameter of the shotshell type ammunition 100. Thus, the first end 104 of the hull 102 is referred to herein as a “rimless” first end 104 because the first end 104 does not project laterally outward from the hull radially beyond the outer cylindrical side surface 106. In other words, the diameter of the hull 102 at the first end 104 is equal to or less than the diameter of the outer cylindrical side surface 106 of the hull 102, which extends to the seat surface 112 and may have a length as previously described. Stated another way, the outer cylindrical side surface 106 may have a first diameter D1, and the outer end surface 114 of the hull 102 at the rimless first end 104 may have a second diameter D2 at least substantially equal to or smaller than the first diameter D1.
In contrast, previously known standard shotshell type ammunition has a rimmed first end, wherein the first end of the hull projects laterally outward radially beyond the cylindrical portion of the hull, so as to define a rim at the first end of the ammunition which is used to seat the ammunition within the firearm (the function performed by the seat surface 112 in embodiments of the present disclosure). In other words, the diameter D2 is greater than the diameter D1 in previously known standard shotshell type ammunition.
With continued reference to FIGS. 1 and 2, the diameter D1 of the outer cylindrical side surface 106 of the hull 102 may vary depending on the size of the shotgun type firearm from which the ammunition is to be fired. As known in the art, shotgun type firearms commonly have one of a 10 gauge bore size, a 12 gauge bore size, a 16 gauge bore size, and a 20 gauge bore size. As non-limiting examples, Table 1 below provides ranges for the maximum diameter D1 of the outer cylindrical side surface 106 of the hull 102 for different firearm bore sizes.










TABLE 1







Bore Size
Maximum Diameter D1









10 Gauge
2.146 centimeters (about 0.845 inches)




to




2.370 centimeters (about 0.933 inches)



12 Gauge
2.032 centimeters (about 0.800 inches)




to




2.250 centimeters (about 0.886 inches)



16 Gauge
1.867 centimeters (about 0.735 inches)




to




2.080 centimeters (about 0.819 inches)



20 Gauge
1.775 centimeters (about 0.699 inches)




to




1.948 centimeters (about 0.767 inches)










The ranges provided in Table 1 are provided as examples only, and the maximum diameter D1 of the outer cylindrical side surface 106 of the hull 102 may be outside the ranges set forth in Table 1 for the corresponding firearm bore size in additional embodiments of the disclosure.
FIG. 3. illustrates another embodiment of a shotshell type ammunition 130 of the present disclosure. The shotshell type ammunition 130 is generally similar to that shown in FIG. 1, and includes a hull 132, gun powder 147 disposed within the hull 132, a sabot 138 disposed within the hull 132, and at least one projectile 148 disposed within the sabot 138. The gun powder 147, sabot 138, and at least one projectile 148 may be as previously described with reference to FIG. 1.
The hull 132 of the ammunition 130, like the ammunition 100, has a rimless first end 134, an opposing second end 140, and a seat surface 142 for seating the hull 132 against a complementary seat surface in a firing chamber of a firearm. The seat surface 142 may be located a distance L from an outer end surface 141 of the hull 132 at the rimless first end 134, as described with reference to FIG. 1. An outer cylindrical side surface 136 may extend from the rimless first end 134 of the hull 132 to the seat surface 142 of the hull 132.
The hull 132 of FIG. 3, however, has a multi-part construction, and may include a cylindrical portion 135 that extends from the rimless first end 134 of the hull 132, and a cylindrical ring member 133 disposed concentrically around the cylindrical portion 135. In some embodiments, the ammunition 130 may be formed by disposing a cylindrical ring member 133 around the cylindrical portion of the hull of a conventional, previously known shotshell type ammunition. A longitudinal end surface of the cylindrical ring member 133 defines the seat surface 142 of the hull 132. An outer cylindrical side surface of the cylindrical ring member 133 defines the outer cylindrical side surface 136 of the hull 132 extending from the rimless first end 134 of the hull 132 to the seat surface 142 of the hull 132.
As non-limiting examples, the cylindrical portion 135 may comprise a plastic material, and the cylindrical ring member 133 may comprise a metal.
The opposing second end 140 of the hull 132 may be closed by, for example, folding and/or crimping the opposing second end 140 of the hull 132, which comprises an end of the cylindrical portion 135.
FIGS. 4 and 5 illustrate another embodiment of a shotshell type ammunition 150 of the disclosure. The shotshell type ammunition 150 includes a hull 152, gun powder 166 disposed within the hull 152, a sabot 160 disposed at least partially within the hull 152, and at least one projectile 162 disposed with the sabot 160. Like the previously described hulls, the hull 152 has a rimless first end 154. The hull 152 also has an opposing second end 158, and a seat surface 156 for seating the hull 152 against a complementary seat surface in a firing chamber of a firearm. In the embodiment shown in FIGS. 4 and 5, the second end 158 of the hull 152 is open, and a forward end of the sabot 160 projects out from and longitudinally beyond the open second end 158 of the hull 152.
The hull 152 includes a cylindrical portion 153 that extends from the rimless first end 154 of the hull 152 to the open second end 158 of the hull 152. A longitudinal end surface of the cylindrical portion 153 defines the seat surface 156 of the hull 152. An outer cylindrical side surface 155 of the cylindrical portion 153 of the hull 152 may extend from at least proximate the rimless first end 154 of the hull 152 to the seat surface 156 of the hull 152. The diameter of the outer cylindrical side surface 155 of the cylindrical portion 153 defines a maximum diameter of the hull 152.
The cylindrical portion 153 and the rimless first end 154 of the hull 152 may comprise regions of a single unitary body in some embodiments. In other embodiments, they may comprise portions of the hull 152 that are formed separately from one another and subsequently assembled and/or bonded together. The hull 152 may comprise, for example, a metal or a polymer, such as a plastic material. In some embodiments, each of the rimless first end 154 and the cylindrical portion 153 of the hull 152 may comprise a polymer material. As non-limiting examples, such a polymer material may comprise a polycarbonate material, or a nylon material. Further, the polymer material may include a discontinuous filler material, such as glass particles (e.g., fibers).
As shown in FIG. 5, a portion of the sabot 160 is contained within the hull 152, and at least one projectile 162 is disposed within the sabot 160. The at least one projectile 162 disposed within the sabot 160 may be entirely surrounded by and enclosed within the sabot 160 prior to firing the ammunition 150.
As previously mentioned, the sabot 160 may project longitudinally beyond the seat surface 156 at the open end 158 of the cylindrical portion 153 of the hull 152 prior to firing the shotshell type ammunition 150. The sabot 160 may have a forward rounded end surface 165 that projects longitudinally beyond the seat surface 156. The rounded end surface 165 may project beyond the end surface at the open end of the cylindrical portion 153 prior to firing of the shotshell type ammunition 150. The rounded end surface 165 may have, for example, a cone shape or a dome shape. In other embodiments, the sabot 160 may not have a rounded end surface 165, but may instead be flat, for example.
The sabot 160 may include two or more portions that fold together to enclose the one or more projectiles 162 therein. As the sabot 160 (with the one or more projectiles 162 carried therein) exits the barrel of a firearm upon firing the ammunition 150, the two or more portions of the sabot 160 may at least partially separate from one another so as to release the projectiles 162 from the sabot 160. The sabot 160 may include at least one feature, such as a recess or aperture 167, at the forward rounded end surface 165 of the sabot 160, which may be configured to urge the at least partial separation of the sabot and release of the one or more projectiles 162 as the sabot 160 exits the barrel of a firearm upon firing the ammunition 150. In some embodiments, a portion of the sabot 160 may define a hinge member 169 that connects the two or more separable portions of the sabot 160 such that the portions do not completely separate from one another upon firing the ammunition 152.
The sabot 160 may be retained within the hull 152 using, for example, an interference fit between the sabot 160 and the hull 152. For example, the sabot 160 may have a cylindrical outer side surface having a maximum diameter, and the hull 152 may have a cylindrical inner side surface having a minimum diameter equal to or smaller than the maximum diameter of the cylindrical outer side surface of the sabot 160. In such a configuration, the sabot 160 may be inserted into the hull 152 using a press-fitting process and/or a shrink-fitting process, for example. The mechanical interference between the cylindrical outer side surface of the sabot 160 and the cylindrical inner side surface of the hull 152 retains the sabot 160 within the hull 152 until the ammunition 152 is fired from a firearm.
As shown in FIG. 5, the rimless first end 154 of the hull 152 may include a primer 168 for firing the ammunition 150. When struck by a firing pin of a shotgun type firearm, the primer 168 may ignite the gunpowder 166 within the hull 152, which in turn may eject the sabot 160 (with the at least one projectile 162 carried therein) out from the second end 158 of the hull 152.
The one or more projectiles 162 within the sabot 160 of the ammunition 150 may be as previously described in relation to the one or more projectiles 120 of the ammunition 100, with reference to FIGS. 1 and 2.
Similar to the ammunition 100 of FIGS. 1 and 2, the seat surface 156 may be located a distance L from an outer end surface of the hull 152 at the rimless first end 154, and, as non-limiting examples, the distance L may be at least about 0.318 centimeters (about 1⁄8 of an inch), at least about 0.635 centimeters (about 1⁄4 of an inch), at least about 1.270 centimeters (about 1⁄2 of an inch), or even at least about 2.540 centimeters (about 1 inch).
The outer cylindrical side surface 155 of the hull 152 may define a maximum diameter of the shotshell type ammunition 150. The first end 154 of the hull 152 is rimless, as the first end 154 does not project laterally outward from the hull 152 radially beyond the outer cylindrical side surface 155. In other words, the diameter of the hull 152 at the first end 154 is equal to or less than diameter of the outer cylindrical side surface 155 of the hull 152, which extends to the seat surface 156 and may have a length as previously described. The diameter of the outer cylindrical side surface 155 of the hull 152 may vary depending on the size of the shotgun type firearm from which the ammunition is to be fired, as previously discussed. As non-limiting examples, the maximum diameter of the outer cylindrical side surface 155 of the hull 152 may be within the ranges set forth in Table 1 above for the different corresponding firearm bore sizes.
The second end of the shotshell type ammunition 150 is not crimped, as is conventional shotshell type ammunition. As a result, the interior surface of the barrel of a firearm used to fire the shotshell type ammunition 150 does not need to include a forcing cone (a frustoconical shaped portion of the interior surface), as do the barrels of conventional shotgun type firearms used to fire conventional shotshell type ammunition. Thus, the interior surface of the barrel of a shotgun type firearm configured to fire the shotshell type ammunition 150 may have an at least substantially uniform diameter extending from a location of the seat surface 156 when the ammunition 150 is fully seated within the barrel to a location proximate the distal end of the barrel (but for any variation provided by a so-called “choke tube,” which is commonly employed at the distal end of the barrel of shotgun type firearms). The lack of such a forcing cone in embodiments of firearms of the present disclosure may reduce recoil felt by users of such firearms.
FIG. 6 illustrates another embodiment of a shotshell type ammunition 170 similar to that of FIGS. 4 and 5, but further including an additional sabot 172 disposed between the sabot 160 and the hull 152. In other words, the additional sabot 172 may be disposed within the hull 152 of the shotshell type ammunition 170, and the sabot 160 that encloses the one or more projectiles 162 may be disposed within the additional sabot 172. The additional sabot 172 may have a configuration similar to previously known standard configurations for sabots (e.g., a “wad”) in shotshell type ammunition, and may be used to provide a relatively tighter gas-tight seal between the sabot 160 and the barrel of a firearm from which the ammunition 170 is fired. For example, the additional sabot may have a cup-shaped configuration that includes two or more portions that, when folded together, form a generally cylindrical side wall that extends from a first closed end to an open second end. The sabot 160 may protrude from the open second end of the additional sabot 172 prior to firing of the ammunition 150 in some embodiments.
Additional embodiments of the present disclosure include shotgun type firearms that are configured for firing shotshell type ammunition as described herein. FIG. 7 illustrates a non-limiting example embodiment of a shotgun type firearm 180 of the present disclosure. The shotgun type firearm 180 may comprise a magazine 182 configured to hold two or more rounds of shotshell type ammunition as described herein. The magazine 182 may be configured to be attached and detached from the firearm 180 in a repeatable manner. The shotgun type firearm 180 may comprise a semi-automatic or automatic repeating firearm, and ammunition may be sequentially fed from the magazine into the firing chamber of the firearm 180 in an at least substantially automatic manner upon firing the firearm. The magazine 182 may be removed from the firearm to reload the magazine 182 with ammunition, after which the magazine 182 may again be coupled with the firearm 180.
FIG. 8 illustrates a cross-sectional side view of the magazine 182 of FIG. 7, separate from the shotgun type firearm 180, and loaded with five rounds of shotshell type ammunition 150 as previously described with reference to FIGS. 3 and 4. As shown in FIG. 8, the shotshell type ammunition 150 may be configured in a vertical stack when loaded in the magazine 182. FIG. 9 is a top view of the loaded magazine 182 of FIG. 8. In some embodiments, the width of the magazine 182 may be such that a single, vertically oriented stack of shotshell type ammunition 150 fits within the magazine 182, as shown in FIG. 9.
FIG. 10 is an enlarged cross-sectional side view of a portion of the shotgun type firearm 180 of FIG. 7, with a loaded magazine 182 as shown in FIGS. 8 and 9 coupled to the firearm 180. FIG. 10 illustrates one ammunition 150 being fed from the magazine 182 and into a firing chamber 186 of the firearm 180. The firing chamber 186 of the shotgun type firearm 180 may be sized and configured to fire a shotshell type ammunition 150 as previously described herein.
FIG. 11 shows a shotshell type ammunition 150 fully seated within the firing chamber 186. The firing chamber 186 of the shotgun type firearm 180 may have a generally cylindrical inner surface 187 extending through a headspace 188 within the firing chamber 186. The firing chamber 186 further includes a seat surface 190 that is located, sized, and configured to abut against the seat surface 168 of the ammunition 150 when the ammunition 150 is fully seated and properly head spaced within the firing chamber 186. Thus, the seat surface 190 may prevent longitudinal forward movement of the hull 152 within the firearm 180 when the shotshell type ammunition 150 is loaded and fired from the firearm. As used herein, the term “headspace” means a distance from the seat surface 186, which stops forward movement of the ammunition 150 within the firing chamber 186, to the surface at the rimless first end 154 of the hull 152 (FIG. 6), which is the surface against which the bolt of the firearm rests at the time of firing the ammunition 150.
The generally cylindrical inner surface 187 extending through the headspace 188 within the firing chamber 186 may have any appropriate length that is at least as long as the length L of the cylindrical lateral side surface 155 of the hull 152 of the ammunition 150. As non-limiting examples, the generally cylindrical inner surface 187 extending through the headspace 188 may have a length of at least about 0.318 centimeters (about 1⁄8 of an inch), at least about 0.635 centimeters (about 1⁄4 of an inch), at least about 1.270 centimeters (about 1⁄2 of an inch), and at least about 2.540 centimeters (about 1 inch).
FIGS. 12 through 14 are simplified figures illustrating the firing of a shotshell type ammunition 150 as described herein within the barrel 200 of the shotgun type firearm 180 of FIGS. 7 through 11. FIG. 12 illustrates the shotshell type ammunition 150 fully seated within the firing chamber 186 prior to firing the ammunition 150. As previously discussed, the shotshell type ammunition 150 may comprise a hull 152 and a sabot 160 disposed within the hull 152. The sabot 160 may carry one or more projectiles 162 therein, as previously described.
As shown in FIG. 13, upon firing the ammunition 150, the sabot 160 carrying the one or more projectiles 162 therein exits the hull 152 and travels down the barrel 200 of the firearm 180. The one or more projectiles 162 may remain at least substantially enclosed within the sabot 160 as the sabot 160 travels through the barrel 200.
Referring to FIG. 14, as the sabot 160 exits the barrel 200, the two or more portions of the sabot 160 may at least partially separate from one another in such a manner as to release the one or more projectiles 162. As the sabot 160 travels through the air, the air impinging upon the sabot 160 within the recess or aperture 167 may generate forces that urge the separation of the two or more portions of the sabot 160. The opening or separation of the sabot 160 may be further assisted by providing a pressurized gas within the sabot 160, which may urge the separation of the two or more portions of the sabot 160 and assist in releasing the one or more projectiles 162 from the sabot 160 and allowing the trajectory of the one or more projectiles 162 to continue on toward an intended target, while the sabot 160 rapidly decelerates and falls to the ground in relatively closer proximity to the barrel 200. Such a pressurized gas may be provided within the sabot 160 by providing an aperture in the sabot 160 that extends through the end of the sabot 160 proximate the gun powder, so as to allow the pressurized gases generated by the gun powder upon filing of the ammunition 150 to enter into the interior of the sabot 160 as the sabot 160 travels through the barrel 200 of the firearm.
The various embodiments of shotshell type ammunition described herein with reference to FIGS. 1 through 6 are configured to facilitate use of shotshell type ammunition in semi-automatic or automatic shotgun type firearms that include a removable magazine, such as the firearm 180 described with reference to FIGS. 7 through 11. In particular, by utilizing a hull having a rimless first firing end, and a generally cylindrical side surface defining a maximum diameter of the hull, which extends a distance from the rimless first firing end to a seat surface, the ammunition may be consistently stacked within a magazine in a uniform and predictable manner, which may allow consistent feeding of ammunition from the magazine and into the firing chamber of the firearm without jamming.
For example, FIG. 15 illustrates a stack of previously known standard shotshell type ammunition 220, which have rimmed first firing ends. Due to the shape and configuration of the ammunition 220, the ammunition may not be oriented substantially parallel to one another when they are stacked one upon another as shown in FIG. 15. As a result, when such ammunition 220 is stacked one upon another in a magazine, the ammunition 220 may not be capable of feeding from the magazine into a firing chamber of a firearm in a reliable and consistent manner without jamming.
In contrast, FIG. 16 illustrates a stack of shotshell type ammunition 100 as described herein with reference to FIGS. 1 and 2. As shown in FIG. 16, the shotshell type ammunition 100 may be oriented substantially parallel to one another when stacked one upon another, such as within a magazine 182 as described herein. The outer cylindrical side surfaces 106 of the ammunition 100 abut against one another in such a manner as to cause the ammunition 100 to align parallel to one another in the stack. The lack of a rimmed end on the ammunition 100 further enables the ammunition 100 to be stacked in a parallel configuration. As a result, the ammunition 100 may be capable of feeding from the magazine 182 and into a firing chamber of a firearm 180 in a relatively more reliable and consistent manner without jamming, as compared to previously known standard shotshell ammunition 220 (FIG. 15).
Another advantage of the various embodiments of shotshell type ammunition described herein is that the ammunition (and corresponding shotgun type firearms) may be configured differently for use with lethal and less-lethal ammunition, so as to prevent lethal ammunition from being fired from firearms intended for use only with less-lethal ammunition. For example, referring again to FIGS. 1 and 2, the distance L from the outer end surface 114 of the hull 102 to the rimless first end 104 may be configured to correspond to a specific configuration of the shotshell type ammunition 100. For example, a first type of lethal ammunition 100 (i.e., carrying one or more lethal projectiles 120) may have a different length L compared to a second type of less-lethal ammunition 100 (i.e., carrying one or more less-lethal or non-lethal projectiles 120). Further, a barrel of a shotgun type firearm may be configured to be compatible only with shotshell type ammunition having a specific length L. For example, in one embodiment, a lethal shotgun type firearm may be configured to be compatible with only lethal shotshell type ammunition having a specific distance L, while a non-lethal or less-lethal shotgun type firearm may be configured to be compatible only with a non-lethal or less-lethal shotshell type ammunition having a shorter specific distance L. In such a configuration, the lethal shotshell type ammunition would be too long to fit properly within the firing chamber of the non-lethal shotgun type firearm, and, therefore, the lethal ammunition would not fire in the non-lethal shotgun type firearm. Such a configuration may aid in limiting accidents when only one type of shotshell ammunition is intended to be used with a specific shotgun type firearm. The other embodiments of shotshell type ammunition described herein also may be configured differently for lethal and less-lethal ammunition, and corresponding firearms may be fabricated and configured for use with one of the lethal or less-lethal types of ammunition, so as to prevent lethal ammunition from being fired from a firearm intended for use only with less-lethal (e.g., non-lethal) types of ammunition.
The example embodiments of the disclosure described above do not limit the scope of the invention, since these embodiments are merely examples of embodiments of the invention, which is defined by the scope of the appended claims and their legal equivalents. Any equivalent embodiments are intended to be within the scope of this invention. Indeed, various modifications of the disclosure, in addition to those shown and described herein, such as alternate useful combinations of the elements described, will become apparent to those skilled in the art from the description. Such modifications and embodiments are also intended to fall within the scope of the appended claims.

## Claims

1. In combination, a semi-automatic or automatic shotgun loaded with a rimless shotshell ammunition,
wherein the shotgun comprises:
a barrel having an interior surface defining a bore;
a firing chamber in which the rimless shotshell ammunition is chambered;
a generally cylindrical inner surface extending through a headspace within the firing chamber; and
a seat surface within the firing chamber, the seat surface abutting against a complementary scat surface of a hull of the rimless shotshell ammunition and preventing longitudinal forward movement of the hull within the shotgun when the shotshell ammunition is fired from the shotgun;

wherein the rimless shotshell ammunition comprises:
a polymeric hull having a rimless first end comprising a primer for firing the ammunition, an opposing second end from which a projectile may be ejected out from the hull upon firing the ammunition, a cylindrical portion extending from the rimless first end to an open end of the cylindrical portion at the second end of the hull, an end surface of the cylindrical portion at the second end of the hull defining a seat surface of the plastic hull for seating the hull against a complementary seat surface in a firing chamber of a shotgun firearm, the seat surface located a distance from an outer end surface of the hull at the rimless first end, and an outer cylindrical side surface of the cylindrical portion extending from the rimless first end of the hull to the seat surface of the hull, wherein the hull is sized and configured for chambering in a firing chamber of a shotgun firearm, the distance the seat surface is located from the outer end surface of the hull at the rimless first end is at least about 1.270 centimeters (about 1⁄2 of an inch), and the hull has a maximum diameter in a range extending from about 1.775 centimeters (about 0.699 inch) to about 2.370 centimeters (about 0.933 inch);
a sabot disposed within the hull; and
at least one projectile disposed within the sabot.

2. The combination of claim 1, wherein the distance the seat surface is located from the outer end surface of the hull at the rimless first end is at least about 2.540 centimeters (about 1 inch).

3. The combination of claim 1, wherein the hull has a maximum diameter of about 2.159 centimeters (about 0.850 inches) or less.

4. The combination of claim 1, wherein the outer cylindrical side surface has a first diameter, and wherein the outer end surface of the hull at the rimless first end has a second diameter at least substantially equal to or smaller than the first diameter.

5. The combination of claim 1, further comprising a groove extending into the hull on a lateral side of the hull proximate the rimless first end of the hull, the groove located and configured for use in ejection of the shotshell ammunition from a firearm.

6. The combination of claim 1, wherein the sabot projects longitudinally beyond the end surface at the open end of the cylindrical portion prior to tiring of the shotshell ammunition.

7. The combination of claim 6, wherein the sabot has a rounded end surface, the rounded end surface of the sabot projecting beyond the end surface at the open end of the cylindrical portion prior to firing of the shotshell ammunition.

8. The combination of claim 1, wherein the sabot is retained within the hull using an interference fit between the sabot and the hull.

9. The combination of claim 8, wherein the sabot has a cylindrical outer side surface having a maximum diameter, and wherein the hull has a cylindrical inner side surface having a minimum diameter equal to or smaller than the maximum diameter of the cylindrical outer side surface.

10. The combination of claim 1, wherein the cylindrical portion and the rimless first end of the hull are regions of a single unitary body.

11. The combination of claim 10, wherein the single unitary body comprises a plastic material.

12. The combination of claim 1, wherein the at least one projectile disposed within the sabot comprises a plurality of rounded pellets.

13. A method of using a shotshell ammunition in a semi-automatic or automatic shotgun firearm, comprising:
providing a semi-automatic or automatic shotgun, wherein the shotgun comprises:
a barrel having an interior surface defining a bore;
a firing chamber in which the rimless shotshell ammunition is chambered;
a generally cylindrical inner surface extending through a headspace within the firing chamber; and
a seat surface within the firing chamber, the seat surface abutting against a complementary seat surface of a hull of the rimless shotshell ammunition and preventing longitudinal forward movement of the hull within the shotgun when the shotshell ammunition is fired from the shotgun;

providing a shotshell ammunition, wherein the ammunition comprises:
a polymeric hull having a rimless first end, an opposing second end from which a projectile may be ejected out from the hull upon firing the ammunition, a cylindrical portion extending from the rimless first end to an open end of the cylindrical portion at the second end of the hull, an end surface of the cylindrical portion at the second end of the hull defining a seat surface for seating the hull against a complementary seat surface in a firing chamber of a shotgun firearm, the seat surface located a distance from an outer end surface of the hull at the rimless first end, and an outer cylindrical side surface of the cylindrical portion extending from the rimless first end of the hull to the seat surface of the hull, wherein the hull is sized and configured for chambering in a firing chamber of a shotgun firearm such that the distance the seat surface is located from the outer end surface of the hull at the rimless first end is at least about 1.270 centimeters (about 1⁄2 of an inch), and such that the hull has a maximum diameter in a range extending from about 1.775 centimeters (about 0.699 inches) to about 2.370 centimeters (about 0.933 inches);

a primer at the rimless first end of the hull for firing the ammunition; and
at least one projectile within a sabot, wherein the sabot is inserted at least partially into the hull;
loading the ammunition into a vertically stacked magazine;
inserting the magazine into the shotgun; chambering a round of the ammunition into the firing chamber; and firing the shotgun.

14. The method of claim 13, wherein the distance the seat surface of the hull is located from the outer end surface of the hull at the rimless first end is at least about 2.540 centimeters (about 1 inch).

15. The method of claim 13, wherein the outer cylindrical side surface of the hull has a first diameter, and such that the outer end surface of the hull at the rimless first end has a second diameter at least substantially equal to or smaller than the first diameter.

16. The method of claim 13, wherein the hull includes a groove extending into the hull on a lateral side of the hull proximate the rimless first end of the hull, the groove located and configured for use in ejection of the shotshell ammunition from a firearm.

17. The method of claim 13, wherein the sabot projects out from the hull longitudinally beyond the end surface at the open end of the cylindrical portion prior to firing of the shotshell ammunition.

18. The method of claim 17, wherein the rounded end surface of the sabot projects beyond the end surface at the open end of the cylindrical portion prior to firing of the shotshell ammunition.

19. The method of claim 13, wherein the sabot at least partially inserted into the hull is retained within the hull with an interference fit between the sabot and the hull.

20. The method of claim 19, wherein the sabot at least partially inserted into the hull is press fitted at least partially into the hull.