Rimless shotshell cartridge and shotgun firearm system

Abstract

A rimless shotshell cartridge hull having a tubular body with an internal bore and an outer surface. The tubular body is configured with a raised portion formed along a circumference of the surface at a first end of the body. The raised portion is configured with an annular stop proximate the first end of the body. The raised portion configured with a radial groove formed along the circumference of the outer surface between the annular stop and the first end of the body. The raised portion has a uniform outer diameter, and the tubular body and the raised portion are formed as a one-piece nonmetallic member. A shotgun firearm, and a magazine cartridge feeding device.

Description

RIMLESS SHOTSHELL CARTRIDGE AND SHOTGUN FIREARM SYSTEMField of the Disclosure

[0001] This disclosure relates to a shotshell cartridge, a shotgun firearm, and rimless shotshell related technologies.Background

[0002] There has arisen an increased need for a cost effective and simple to manufacture shotshell type ammunition that features a “rimless” configuration as opposed to the traditional “rimmed” configuration which still dominates the commercial shotshell market at this time. Rimmed cartridge configurations were first developed in the early to middle 19thcentury and then became prevalent in all three major types of small arms (i.e. firearms). These three types of firearms are known as pistols (i.e. “handguns”), rifles, and shotguns. It can also be noted that rifles and shotguns are collectively known as “long guns.”

[0003] In the later 19ththru early 20thcenturies the concept of using a detachable box magazine was developed to become the preferred means of feeding ammunition into pistols and rifles, especially those firearms that also featured auto-loading operating systems (i.e., “semi-automatic”, “automatic”, and “fully automatic”). Rimmed cartridges were developed well before detachable box magazines and auto-loading firearms. Therefore a new cartridge form factor was developed that would stack neatly in the new vertical column configurations presented by a box magazine feeding approach. These new cartridges became known as rimless cartridges whereby the hulls featured an extraction rim that no longer protruded beyond the largest main outer diameter of the cartridge hull, such as with the rimmed designs.

[0004] By the mid to late 20thcentury, auto-loading pistols and rifles that utilized detachable box magazines had become the dominant design approach in the firearms industry as a whole, and especially in military, paramilitary, and law enforcement applications. Shotgun firearms, however, did not ultimately follow this trend because no suitable rimless shotshell cartridge design had yet been developed to succeed the traditional rimmed shotshell cartridge.

[0005] Since the late 20thcentury there have been limited attempts at introducing a rimless shotshell cartridge for a shotgun firearm system. One attempt was a joint venture between the Olin Corporation and Heckler and Koch GMBH which become known commercially as “CAWS” (Close Assault Weapon System). Another attempt was a venture by Intrepid Tactical SolutionsLLC which became known commercially as the “RAS-12.”

[0006] The CAWS shotshell cartridge featured a dual rim “belted” head design which represented the first attempt at departing from the traditional rimmed head design used in shotshells. The head design of the CAWS established in effect a recognizably rimless form factor to the loaded cartridge, although the design was still intended to utilize the same extractor profile as that which would be expected to be utilized with a rimmed shotshell. This was due to the desire to also facilitate being able to switch between traditional rimmed shotshells and the new CAWS shotshell in the same shotgun firearm. The CAWS shotgun firearm thus featured a firing chamber that could accept either shotshell. The CAWS shotgun firearm also featured loading, feeding, extraction, and ejection processes that could accommodate the use of either type of shotshell as desired. Because the CAWS shotshell hull was made entirely of brass, this prevented the use of traditional crimp methods. Therefore the CAWS utilized a glued-in “crimped plug” style approach to the retaining of the loaded shot column into the hull.

[0007] The RAS-12 shotshell cartridge featured an overall recognizably rimless style of form factor whereby the cartridge was designed to headspace on the “case mouth” (the open forward end) of the cartridge hull. This is the same headspacing approach used by common pistol cartridges such as the .45 ACP, 9mm Luger, and .40 S&W. The RAS-12 shotshell cartridge also featured an interference fit (i.e., a “press fit”) between the inside surface of the cartridge hull and the outside surface of a discarding sabot. This sabot was used to deliver the shot projectiles down the bore and out the muzzle of the shotgun firearm. The front nose of the discarding sabot protruded longitudinally from the cartridge hull and was rounded in order to facilitate the feeding of the RAS- 12 shotshell cartridge out of the detachable box magazine and into the firing chamber. The RAS- 12 shotgun firearm in turn featured a bore without a forcing cone due to the need for a forcing cone being eliminated by the particular design, function, and interaction of the sabot and hull components while in the firing chamber.

[0008] Even though each system sought to provide to the user the advantages of utilizing detachable box magazines and auto-loading types of firearm operation, the commercial viability and utility of both the CAWS and the RAS-12 shotshell and shotgun systems were negatively affected by the relatively higher complexity and cost of each system as opposed to the traditional rimmed shotshell and shotgun systems of the prior art. The complexities found in each system's approach was especially apparent in the unique and non-standard loading processes needed for themanufacturing of each shotshell cartridge. The higher production costs were primarily due to the relatively unusual materials used in each system's shotshell cartridge design as opposed to the standard materials used for the production of modem rimmed shotshell cartridges. Therefore, neither the CAWS nor the RAS-12 shotshell cartridges and shotgun firearms enjoyed any significant measure of commercial success or marketplace acceptance. The HK CAWS was not put into commercial or military production beyond its initial development stage. The RAS-12 saw limited production from 2013 to 2014, but none since. A need remains for improved rimless shotshell cartridges and firearm systems utilizing such cartridges.Summary

[0009] Disclosed herein is a rimless shotshell cartridge hull and shotgun firearm system that overcomes the limitations and disadvantages of the prior art with respect to utilizing detachable box magazines in an auto-loading shotgun firearm. Previous to this disclosure, while historically both the pistol and the rifle have been able to successfully transition from primarily using rimmed cartridges to primarily using rimless cartridges, no such similar transition has been provided in a viable fashion for the modem shotshell ammunition and shotgun firearm marketplace.

[0010] According to an aspect of the invention, a rimless shotshell cartridge hull includes a tubular body having an internal bore and an outer surface. The tubular body is configured with a raised portion formed along a circumference of the outer surface at a first end of the body. The raised portion is configured with an annular stop proximate the first end of the body, and a radial groove formed along the circumference of the outer surface between the annular stop and the first end of the body, The raised portion has a uniform outer diameter. The tubular body and the raised portion are formed as a one-piece nonmetallic member.

[0011] According to another aspect of the invention, a shotgun firearm includes a barrel configured to accept a rimless shotshell cartridge, wherein the shotshell cartridge includes a hull configured with a tubular one-piece nonmetallic body having an internal bore and an outer surface. The tubular body is configured with a raised portion formed along a circumference of the outer surface at a first end of the body. The raised portion is configured with an annular stop proximate the first end of the body, and a radial groove formed along the circumference of the outer surface between the annular stop and the first end of the body. The raised portion has a uniform outer diameter. The barrel is configured with an annular stop surface configured to interact with theannular stop on the rimless shotshell cartridge hull. A bolt is configured with a recessed boltface to accept the first end of the rimless shotshell cartridge hull.

[0012] According to another aspect of the invention, a magazine cartridge feeding device for a shotgun firearm includes a walled body with an open upper end. The walled body is configured to hold a plurality of rimless shotshell cartridges, wherein each shotshell cartridge is configured with a hull comprising: a tubular one-piece nonmetallic body having an internal bore and an outer surface; the tubular body configured with a raised portion formed along a circumference of the outer surface at a first end of the body; the raised portion configured with an annular stop proximate the first end of the body and a radial groove formed along the circumference of the outer surface between the annular stop and the first end of the body, wherein the raised portion has a uniform outer diameter. A spring loaded follower is configured to push the shotshell cartridges toward the open upper end of the walled body. The walled body is configured for detachable engagement with a port in a shotgun firearm.Brief Description of the Drawings

[0013] In the detailed description which follows, reference is made to the accompanying drawings which form a part thereof. The use of the same symbols in different drawings will typically indicate references to similar or identical items. The illustrative embodiments described in the detailed description and drawings are provided merely for illustration and are not intended to be limiting. Other embodiments may be put to use, and other changes may be made, without departing from the spirit or scope of this disclosure. The figures may not be necessarily drawn to scale, and certain features may be shown exaggerated in scale or in generalized or schematic form, in the interest of clarity and conciseness.

[0014] FIG. 1 A is a perspective view of a conventional shotshell cartridge.

[0015] FIG. IB is another perspective view of the conventional shotshell cartridge of FIG. 1 A.

[0016] FIG. 2A is a perspective view of a rimless shotshell cartridge embodiment according to an example of the present disclosure.

[0017] FIG. 2B is another perspective view of the rimless shotshell cartridge embodiment of FIG. 2A.

[0018] FIG. 3A is a schematic of a basewad component embodiment according to an example of the present disclosure.

[0019] FIG. 3B is another schematic of the basewad component of FIG.3A.

[0020] FIG. 4 is a cross section of a rimless shotshell cartridge hull tubular body and inner basewad component according to an example of the present disclosure.

[0021] FIG. 5 is a close-up view of a rimless shotshell firing chamber embodiment with a headspacing approach according to an example of the present disclosure.

[0022] FIG. 6 is a perspective view of a shotgun bolt embodiment according to an example of the present disclosure.

[0023] FIG. 7 is a perspective cross section of a barrel, firing chamber area, barrel extension, and bolt of a shotgun configured to fire rimless shotshells according to an example of the present disclosure.

[0024] FIG. 8 is a perspective cross section of a rimless shotshell cartridge hull outer tubular body and inner basewad component installed in the firing position of the barrel extension of FIG.7.

[0025] FIG. 9 is a partial schematic of a rimless shotshell cartridge detachable box magazine embodiment according to an example of the present disclosure.

[0026] FIG. 10 is an isometric projection schematic of a rimless shotshell cartridge detachable box magazine embodiment according to an example of the present disclosure.

[0027] FIG. 11 is a schematic of a rimless shotshell detachable box magazine embodiment loaded with a rimless shotshell cartridge according to an example of the present disclosure.

[0028] FIG. 12 is a schematic of a conventional rimmed shotshell detachable box magazine loaded with a rimmed shotshell cartridge.

[0029] FIG. 13 is a schematic of shotgun firearm with a detachable box magazine embodiment according to an example of the present disclosure.Detailed Description

[0030] Disclosed herein are techniques, methods, and devices to enable the manufacturing and production of a cost effective rimless shotshell cartridge, detachable cartridge magazine, and shotgun firearm system.

[0031] FIG. 1 A shows a perspective view of a conventional rimmed shotshell cartridge 5. The cartridge 5 consists of a plastic material tubular body 7 with a metal cover 9 placed around the base end. The metal cover 9 is placed around the base end in such a way as to both provide a primer12 retaining pocket and to also provide an external protruding outer extraction rim surface, as described below. As shown in FIG. 1 A, the metal cover 9 terminates with a protruding or raised rim 10 with a greater diameter compared to the overall diameter of the tubular body 7. The raised rim 10 prominently extends outward beyond the outer surface of the tubular body 7. FIG. 1 B shows the conventional rimmed shotshell cartridge 5 of FIG. 1 A from another perspective, exposing a “star” crimped front end 14 of the cartridge.FIG. 2 A shows a perspective view of a fully loaded and fully functional rimless shotshell cartridge 20 embodiment of the present disclosure. The cartridge 20 is formed with a tubular body 22 having an internal bore 24 and an outer surface 26. The tubular body 22 is configured with a raised portion 28 formed along a circumference of the outer surface 26 at a first end 30 of the body. The raised portion 28 is configured with an annular stop 32 (further described below) proximate the first end 30 of the body 22. The raised portion 28 is also configured with a radial groove 34 formed along the circumference of the outer surface 26 between the annular stop 32 and the first end 30 of the body 22. The raised portion 28 has a uniform outer diameter. Cartridge 20 embodiments are formed with the tubular body 22 and the raised portion 28 configured as a one-piece nonmetallic member.

[0032] FIG. 2B shows another perspective of the rimless cartridge 20 of FIG. 2A. As shown in FIGS. 2A and 2B, the tubular body 22, along with the raised portion 28, is formed as a singlepiece member of a nonmetallic material. Embodiments of the disclosed rimless cartridge 20 may be configured for operational use with a suitable firearm as disclosed herein (e.g., “12 gauge” or a 0.729” typical inner diameter barrel bore specification). Other embodiments of the rimless cartridges 20can be also configured to operate in suitable firearms configured with other established popular shotgun bore specifications (e.g., “20 gauge” or a 0.615” typical inner diameter, or “10 gauge” or a 0.775” typical inner diameter). Embodiments of the rimless cartridges 20 can also be configured to accept and contain single or multiple projectiles in various popular forms known as “birdshot”, “buckshot”, “slugs”, and “less-lethal”, “non-lethal”, or “marking” (i.e., “impact simulation”). Embodiments of the rimless cartridge 20feature a shotshell cartridge body 22 or hull into which is loaded the shot column (i.e., gas seal, shot wad, projectiles, etc.) over an amount of gunpowder loaded in a prior loading step as known in the art. Embodiments of the shotshell cartridges 20 can be configured to hold the shot column securely in place within the internal bore 24 via common shotshell crimping methods as known in the art (e.g., folded, (i.e., “star”, or roll style crimps). FIG. 2 A shows a rimless cartridge 20 embodiment configured with aroll style crimp 36 at a second end 38 of the tubular body 22. FIG. 2B shows a rimless cartridge 20 configured with a standard shotshell primer 40 (e.g., industry model 209 primer) pressed into place at the base of the first end 30.FIG. 3A shows a rimless shotshell 20 inner basewad 42 component. The basewad 42 component has a front end 44, a back end 46, and an orifice 48 providing a pass through for the primer 40. Embodiments of the basewad 42 component can be formed as nonmetallic members of the same material as the tubular body 22 of the cartridges 20. FIG. 3B shows the basewad 42 component from the back end 46.

[0033] FIG. 4 shows a cross section of a rimless shotshell cartridge 20 embodiment with a basewad component 42 inserted into and press fit (i.e., interference fitted) into the lower area of the bore 24. These two components, when put together in the manner disclosed herein, comprise a complete rimless shotshell cartridge 20 consisting of two pieces which can both be made from the same nonmetallic material. Embodiments of the tubular body 22 and the basewad 42 can be produced using suitable polymers and can be manufactured using conventional production techniques as known in the art (e.g., injection molding or compression forming (i.e., press and die) processes). By means of comparison and contrast, conventional rimmed shotshell cartridge hulls generally consist of three pieces as shown in FIGS. 1A and IB. Thus, the rimless shotshell cartridges 20 of the present disclosure can be seen as exhibiting the key advantages of being able to be manufactured more efficiently and with lower material costs than any conventional rimmed or rimless shotshell cartridges.

[0034] FIG. 4 also shows the design features provided by the rimless cartridge 20 embodiments for both a shrouded primer pocket 48 and a forward open end 50. The forward open end 50 is configured to accept either folded “star” or roll style common shotshell crimp methods in order to securely retain the shot column when loaded as a complete rimless shotshell cartridge 20. The “flash hole” 52 in the rimless basewad 42 component serves the function of allowing a hot shower of sparks from the primer 40 to come into contact with the gunpowder present in the cartridge bore 24. This flash hole 52 is of an inner diameter that is smaller than the outer diameter of the main cylindrical primer 40 body. This enables the rearward facing perpendicular wall surface of the rimless basewad 42 component to move and compress against the top surface of the end of the main cylindrical primer body wherein the flash hole for the primer itself is located during ignition of the gunpowder in the cartridge 20. This compression seals the gases of cartridge ignition and prevents such gases from escaping through the primer pocket, around the primer, andonto the boltface. The forward facing circular outer thin edge of the rimless inner basewad 42 component is configured to compress against the inner cylindrical surface of the rimless tubular hull 22 component. This compression seals the gases of cartridge 20 ignition and prevents the gases from escaping in a manner that does not contribute to the energy needed to deliver the loaded shot column out through the muzzle of the firearm (FIG. 13). The relatively thin wall section at the forward open end of the rimless outer hull 22 is easily visible as compared with the relatively thicker wall sections seen towards the rearward inner areas of the rimless outer hull 22. These relatively thin wall sections are configured to support use of either folded or roll style common shotshell crimping methods in retaining the shot column in the bore 24.

[0035] FIG. 4 shows the cartridge 20 with the raised portion 28 having a larger uniform diameter formed along the circumference of the outer surface 26 at the first end 30, compared to the smaller diameter tubular body 22 section. The raised portion 28 is shown configured with an annular stop 32 formed proximate the first end 30 of the body 22. The annular stop 32 provides a headspacing shoulder 33. The raised portion 28 is also configured with a radial groove 34 formed along the circumference of the outer surface 26 between the annular stop 32 and the first end 30 of the body. The base of the first end 30 provides an extraction shoulder 35. FIG. 4 also shows a rimless cartridge 20 embodiment configured with a tubular body 22 wherein the inner wall of the body is tapered in thickness towards the open end 50. Other tubular body 22 embodiments may be implemented with walls having a uniform thickness along the entire length of the body 22 section.

[0036] FIG. 5 shows a close-up view of a rimless shotshell cartridge 20 firing chamber 60 of the present disclosure. The firing chamber 60 is configured with an internal forcing cone 62 at the front of the firing chamber to provide a smooth transition to the main bore of the firearm barrel (FIG. 13). The chamber 60 is also configured with an annular stop surface 64 configured to interact with the annular stop 32 on the rimless shotshell cartridge 20. A key distinction between conventional firing chambers and embodiments of the disclosed firing chamber 60 is the “headspacing” approach used with each chamber. Headspacing entails the “step” surface position of the annular stop surface 64 formed inside the chamber 60.

[0037] Turning to FIGS. 1A and IB, the extraction and the headspacing functions of conventional rimmed shotshell cartridges 5 are performed using the same single protruding rim 10 on the cartridge. As such, with conventional rimmed cartridges 5 the headspacing step in the firing chamber cannot be moved longitudinally along the chamber since the single rim 10 performsmultiple functions. With the rimless cartridge 20 systems of this disclosure, the rearward extraction shoulder 35 in combination with the gap 34 provides the extraction function while the forward headspacing shoulder 33 formed by the annular stop 32 provides the headspacing function. Thus, the position of the headspace step surface 64 in the rimless firing chamber 60 can be positioned longitudinally as desired in order to enable the selective acceptance or rejection of rimless shotshell cartridges 20 of different ballistic purposes yet still be configured of the same “gauge” (i.e., “caliber”).

[0038] FIG. 6 shows a schematic of a shotgun firearm bolt 70 embodiment of the disclosure. The bolt 70 is configured with a recessed boltface 72, a single spring-loaded claw style extractor 74, a single spring-loaded plunger style ejector 76, and a firing pin 78 protruding through the recessed boltface 72. Prior to the present disclosure, the implementation of a bolt 70 with a recessed boltface 72 was not a viable option available to shotgun firearm designers needing to accommodate the use of rimmed shotshell cartridges. The recessed boltface 72 serves to securely position the base of the rimless shotshell cartridge 20 so that the extractor 74 and ejector 76 can operate efficiently and reliably, and also serves to eliminate the need for a fixed ejector that is not part of the reciprocating bolt assembly but must be mounted elsewhere within the receiver of the firearm. A recessed boltface 72 design approach is not possible with the use of rimmed cartridges (5 in FIGS. 1 A, IB). This is because only rimless cartridges 20, which do not use the extraction shoulder 35 as a headspace surface and in which the extraction shoulder does not jut out above the main tubular body 22 of the cartridge 20, can be captured within a recessed boltface 72. Furthermore, rimless cartridges 20 enable the use of recessed boltface 72 designs because the headspace annular stop 32 of the rimless cartridge 20 is located some distance forward and separate from the rear of the rimless cartridge 20 hull which contacts the recessed boltface 72 of the bolt 70.

[0039] FIG. 7 shows a cross section of a shotgun barrel 79 firing chamber 60 (see FIG. 5) embodiment, including a forcing cone 80, the initial section of the shotgun bore 82 area, a barrel extension 84, and the bolt 70 (see FIG. 6) of a shotgun firearm of the present disclosure. The barrel extension 84 component is the only component in which is found the perpendicular annular stop surface 64 which provides the headspacing function for the opposing perpendicular annular stop 32 provided by the forward shoulder 33 of the rimless shotshell 20 head design. Therefore, the barrel extension 84 can be easily configured during designing and manufacturing to perform thefunction of selectively accepting and rejecting rimless shotshell cartridges 20 of varying headspace dimension specifications, all the while still supporting the use of cartridges in the same gauge or caliber specification, but thus able to support the use of cartridges of differing ballistic effects (i.e., “lethal” vs. “less-lethal” vs. “non-lethal”, etc.). Such an arrangement could prevent catastrophic situations resulting from the wrong type of rimless shotshell cartridge 20 being accidentally discharged in the wrong type of shotgun firearm having been configured for a particular ballistic purpose yet sized in the same gauge or caliber. An example would be to prevent the loading of a “lethal” rimless cartridge into a shotgun designated and marked as “less-lethal” (i.e., combat vs. riot control, etc.). Such an arrangement is impossible with conventional shotgun firearms using rimmed shotshell cartridges.

[0040] FIG. 8 shows a cross section of a rimless shotshell 20 with an inner basewad 42 placed into firing position within the assembly shown in FIG. 7. The annular stop 32 provided by the forward shoulder 33 of the head design of the rimless shotshell body 22 is shown located coincident with the perpendicular headspacing annular surface 64 provided by the circular recess in the barrel extension 84. The base end 30 of the rimless cartridge 20 is shown engaged within the recessed boltface 72. The thin outer wall sections at the forward (towards the right of the figure) outer circular edge of the rimless shotshell basewad 42 component can be seen as being in a position to work against the inner shape of the firing chamber 60 of the shotgun firearm in a way that ensures that the hot expanding gases from burning gunpowder cannot pass by the seal between the outer surfaces of the rimless basewad 42 component and the coincident inner surfaces of the rimless shotshell body 22.

[0041] FIG. 9 shows a perspective view of the upper portion of a detachable magazine box 90 embodiment of this disclosure. The magazine box 90 retains and presents the rimless shotshell cartridges 20 for feeding purposes into the firing chamber 60 of a shotgun firearm. The magazine box 90 features include opposing rear feed lips 92 at the left and right sides of the rear top of the box 90 to provide a positive stop to the upwards travel of the topmost vertically stacked rimless cartridge(s) 20 while under the pressure of a spring-loaded magazine follower 94. These feed lips 92 are of a dimension and construction that enables sufficient spring pressure under the follower 94 to securely retain and present the rimless cartridges 20 within the rimless cartridge magazine 90 at a position longitudinally parallel with the center line of the cylindrical bore 82 (FIGS. 7 and 8) of the firearm. Opposing front feed lips 96 are formed into the inside surface of the left and rightouter side walls of the magazine box 90 in the vicinity of the front of the topmost rimless shotshell cartridge 20 present in the magazine in order to provide a steadying function to the cartridge during the extraction and feeding phases of the loading cycle of a shotgun firearm, and to provide a downward sloping entrance guide to a cartridge loading chute 97 feature to assist in the loading of a plurality of cartridges 20 into the magazine box 90.

[0042] FIG. 10 shows a partial cross section of the upper portion of the magazine box 90 of FIG. 9, illustrating a rear vertical feed channel 98 formed into the inside of the opposing left and right outer side walls of the magazine box 90 that is configurable to selectively accept and reject rimless shotshell cartridges 20 of a varying headspace dimension specification yet still having the same gauge or caliber specification. A forward feed ramp 99 located at the top of the front wall of the magazine box 90 serves to elevate the front of the rimless cartridge 20 during the feeding phase of the loading cycle. In this cycle, the advancing recessed boltface 72 (FIG. 6) strips the uppermost cartridge 20 from the top of the cartridge stack in the magazine box 90 and pushes it forward with considerable force whereby the forward end 38 of the rimless shotshell cartridge 20 engages with the ramped surface of the forward feed ramp 99. In this rimless shotshell 20 detachable box magazine 90 embodiment, no “rear opposing feed ramps” are needed to help elevate the rear of the rimless cartridge 20 out of the magazine box 90 during the feeding cycle. In contrast, the various conventional rimmed shotgun firearm magazines typically feature and require the utilization of such rear opposing feed ramps.

[0043] FIG. 11 is a schematic of a detachable box magazine 90 embodiment of the present disclosure loaded with a rimless cartridge 20. The rimless magazine 90 retains and presents the rimless cartridges 20 in a position that is longitudinally parallel with the center line of the cylindrical bore 82 of the firearm.

[0044] FIG. 12 shows a schematic of a conventional shotgun rimmed cartridge magazine 100 loaded with a rimmed shotshell cartridge 5. In contrast to the rimeless cartridge 20 magazine 90 of FIG. 11, the rimmed cartridge magazine 100 retains and presents the rimmed cartridges 5 in a position that requires the crimped front end of the cartridge 5 to be angled upwards and thus not in a position that is longitudinally parallel with the center line of the cylindrical bore of the firearm. The horizontally oriented retention and presentation of the rimless shotshell cartridge 20 by the rimless shotgun detachable box magazine 90 presents advantages in the reliability of the feeding cycle of the rimless cartridges 20 as opposed to the reliability associated with the retention andpresentation of rimmed shotshell cartridges 5 by the rimmed shotgun magazine 100.

[0045] FIG. 13 is a schematic of a shotgun firearm 200 of the present disclosure, configured to feed, chamber, fire, extract and eject the rimless shotshell cartridges 20 disclosed herein. The firearm 200 is shown equipped with a detachable box magazine 90 embodiment of the present disclosure. The magazine 90 is inserted into the magwell or magazine port 205 of the shotgun firearm 200. Shotgun firearms 200 with modem sporting rifle (MSR) modular configurations can be easily configured for either the civilian or the “military and law enforcement” (i.e., “Mil I LE”) firearms marketplaces.

[0046] In operation, after being struck by the firing pin (78 in FIG. 6) of the shotgun firearm 200 the primer 40 then ignites the gunpowder in the cartridge bore 24, and the hot expanding gases which result then push the shot column up against the front cartridge crimp 36 which then forces it to open. While still under gas pressure, the shot column then emerges from the confines of the cartridge hull 22, through the forcing cone (80 in FIGS. 7 and 8) of the shotgun 200 barrel 79, and down the bore 82 in order to then exit the muzzle 207.

[0047] Advantages of the disclosed embodiments include a rimless shotshell cartridge 20, detachable magazine 90, and shotgun firearm 200 capable of being efficiently produced in a cost effective manner due to various novel design approaches. This, in turn, enables the use of both common materials and the typical manufacturing processes as used in the modem shotshell cartridge and shotgun firearm industry. Accordingly, the disclosed embodiments facilitate the long overdue transition from rimmed to rimless design types in the shotshell cartridge 20 and shotgun 2000 firearm industry and marketplace.

[0048] In light of the principles and example embodiments described and illustrated herein, it will be recognized that the example embodiments can be modified in arrangement and detail without departing from such principles. In view of the wide variety of useful permutations that may be readily derived from the example embodiments described herein, this detailed description is intended to be illustrative only, and should not be taken as limiting the scope of invention. What is claimed as the invention, therefore, are all implementations that come within the scope of this disclosure, and all equivalents to such implementations.

Claims

ClaimsWhat is claimed is:

1. A rimless shotshell cartridge hull, comprising: a tubular body having an internal bore and an outer surface; the tubular body configured with a raised portion formed along a circumference of the outer surface at a first end of the body; the raised portion configured with an annular stop proximate the first end of the body; the raised portion configured with a radial groove formed along the circumference of the outer surface between the annular stop and the first end of the body; wherein the raised portion has a uniform outer diameter; and wherein the tubular body and the raised portion are formed as a one-piece nonmetallic member.

2. The rimless shotshell cartridge hull of claim 1 wherein the tubular body has an outer diameter different from the outer diameter of the raised portion.

3. The rimless shotshell cartridge hull of claim 1 further comprising a nonmetallic basewad configured for disposal within the bore of the tubular body.

4. The rimless shotshell cartridge hull of claim 1 wherein the tubular body is configured to contain gunpowder and projectiles.

5. The rimless shotshell cartridge hull of claim 4 wherein the tubular body is configured for expulsion of the projectiles from a second end of the body.

6. The rimless shotshell cartridge hull of claim 1 wherein the hull is configured for disposal in a magazine configured to hold a plurality of hulls.

7. The rimless shotshell cartridge hull of claim 1 wherein the hull is configured with an extraction shoulder and a headspacing shoulder.

8. The rimless shotshell cartridge hull of claim 1 wherein the tubular body is configured with a tapered inner wall thickness.

9. A shotgun firearm, comprising: a barrel configured to accept a rimless shotshell cartridge, wherein the shotshell cartridge is configured with a hull comprising: a tubular one-piece nonmetallic body having an internal bore and an outer surface; the tubular body configured with a raised portion formed along a circumference of the outer surface at a first end of the body; the raised portion configured with an annular stop proximate the first end of the body; the raised portion configured with a radial groove formed along the circumference of the outer surface between the annular stop and the first end of the body; wherein the raised portion has a uniform outer diameter; wherein the barrel is configured with an annular stop surface configured to interact with the annular stop on the rimless shotshell cartridge hull; and a bolt configured with a recessed boltface to accept the first end of the rimless shotshell cartridge hull.

10. The shotgun firearm of claim 9 wherein the bolt comprises an extractor configured to engage an extraction shoulder on the rimless shotshell cartridge hull.

11. The shotgun firearm of claim 10 wherein the bolt is configured to automatically extract the rimless shotshell cartridge hull ftom the barrel.

12. The shotgun firearm of claim 9 further comprising a port to receive a magazine configured to hold a plurality of rimless shotshell cartridges for insertion of the cartridges into the barrel.

13. The shotgun firearm of claim 9 wherein the barrel stop surface is selectively positioned within the barrel to accept only rimless shotshell cartridge hulls configured with anannular stop positioned on the hull to correspond with the barrel annular stop surface.

14. The shotgun firearm of claim 9 wherein the barrel stop surface is disposed in a barrel extension section of the barrel assembly.

15. The shotgun firearm of claim 9 wherein the barrel comprises a forcing cone.

16. A magazine cartridge feeding device for a shotgun firearm, comprising: a walled body with an open upper end; the walled body configured to hold a plurality of rimless shotshell cartridges, wherein each shotshell cartridge is configured with a hull comprising: a tubular one-piece nonmetallic body having an internal bore and an outer surface; the tubular body configured with a raised portion formed along a circumference of the outer surface at a first end of the body; the raised portion configured with an annular stop proximate the first end of the body; the raised portion configured with a radial groove formed along the circumference of the outer surface between the annular stop and the first end of the body; wherein the raised portion has a uniform outer diameter; a spring loaded follower configured to push the shotshell cartridges toward the open upper end of the walled body; and wherein the walled body is configured for detachable engagement with a port in a shotgun firearm.

17. The magazine cartridge feeding device of claim 16 further comprising a ramp proximate the open upper end to facilitate extraction of the rimless shotshell cartridges from the walled body.

18. The magazine cartridge feeding device of claim 16 further comprising a first set of feed lips configured to retain the rimless shotshell cartridges in the walled body.

19. The magazine cartridge feeding device of claim 16 further comprising a second set of feed lips spaced apart from the first set of feed lips, wherein the second set of feed lips isconfigured to guide the rimless shotshell cartridges.

20. The magazine cartridge feeding device of claim 16 wherein the walled body comprises a vertical feed channel configured to accept and reject rimless shotshell cartridges having a selected hull specification.

21. The magazine cartridge feeding device of claim 20 wherein the walled body is configured with linear parallel walls to maintain the rimless shotshell cartridges in a horizontal position parallel to one another.

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