Abstract:
Implementations of the present disclosure relate to apparatuses, systems, and methods for constructing, installing, and using a compression follower in a tubular firearm magazine. In particular, the compression follower resides inside a shotgun magazine and replaces the standard follower. The compression follower has a compressible tail, thereby providing the capacity of a standard follower and increased reliability by aligning the follower and a magazine spring.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation of U.S. patent application Ser. No. 14/504,645, filed Oct. 2, 2014, which claims the benefit of United States Provisional Patent Application No. 61/885,970, filed on Oct. 2, 2013, which are hereby incorporated by reference in their entireties. 
     
    
     BACKGROUND OF THE DISCLOSURE 
       [0002]    1. The Field of the Disclosure 
         [0003]    Generally, this disclosure relates to ammunition management in firearms. More specifically, the present disclosure relates to the delivery of ammunition in a tubular shotgun magazine. 
         [0004]    2. Background and Relevant Art 
         [0005]    Repeating shotguns, such as automatic, semi-automatic, or pump-action varieties, are commonly provided with a tubular magazine to hold ammunition. The ammunition, known as cartridges or shells, is held in a linear fashion and delivered to the firing chamber of the shotgun sequentially. Typically, a shotgun magazine will hold between 6 and 10 shells at a time, depending on length of the magazine and size of the shells. The shells may be loaded manually into the magazine, with the first shell inserted into the tubular magazine being the final shell to be fed into the firing chamber. 
         [0006]    The loading process commonly involves the user pressing a shell against the lifter on the underside of the gun, raising the lifter to expose the rear portion of the tubular magazine, and inserting the shell into the magazine. When the user does so, the shell will press against a magazine follower, which, in turn, presses against a magazine spring. The process is repeated, pushing each shell against the rear of the previous shell until the magazine is full. The magazine spring can expand to run the length of the tubular magazine and provides a motive force urging any shells in the magazine toward the rear of the magazine and, ultimately, the firing chamber. The magazine spring acts on the line of shells via the follower. However, the follower may jam within the tubular magazine and thereby cease feeding shells to the firing chamber. A follower is typically a cylindrical body with an outer diameter that substantially matches an interior diameter of a shotgun&#39;s tubular magazine. The follower may jam on debris or dirt in the magazine or simply by rotating. Failures of the follower in the rearward direction can prevent the ammunition from reaching the firing chamber, and therefore, prevent the shotgun from firing. Failures of the follower in the forward direction can prevent a user from loading shells into the magazine, rendering the shotgun inoperable. 
         [0007]    In particular, this is of concern in law enforcement or “home defense” applications. A failure of a follower in either situation will render the shotgun inoperable and place the user of the firearm at risk. Because of the adverse environment a user experiences during need of the shotgun, reliability of the firearm is paramount. However, the prior art solution is less than ideal. A “performance follower” of the prior art is largely similar to the standard cylindrical follower, but it has an extension extending toward and within the inner diameter of the magazine spring. This extension acts as a guide to ensure the spring and follower stay in alignment without the spring kinking and/or the follower jamming. The extension, however, increases the length of the follower considerably and reduces the capacity of the magazine. While a more reliable shotgun with one less shell is better than an unreliable shotgun with the full capacity, a more preferable solution would be a follower that increases reliability without adversely affecting capacity. 
         [0008]    Thus, there are a number of problems with shotgun magazine followers that can be addressed. 
       BRIEF SUMMARY OF THE DISCLOSURE 
       [0009]    At least one implementation of the present disclosure solve one or more of the foregoing or other problems in the art with the storage and delivery of ammunition in a repeating shotgun. 
         [0010]    In one embodiment, a compression follower for use in a tubular shotgun magazine is described. The compression follower has a cylindrical body that can slide within the tubular magazine. The body has a cavity with a spring disposed therein. The body and a tail are compressibly connected by the spring, allowing the tail to compress into the cavity within the body. 
         [0011]    In another embodiment, a compression follower for use in a tubular shotgun magazine with a forward end and a rearward end is decribed. The compression follower has a cylindrical body with an outer diameter substantially matching the interior diameter of the magazine and a tail of smaller diameter extending toward the forward end of the magazine, the tail also fitting within the inner diameter of the magazine spring. The tail and body are compressibly connected, allowing the tail to compress into a cavity within the body. 
         [0012]    In another embodiment, a system for improving shotgun performance includes a tubular shotgun magazine having a distal end and a proximal end, a magazine coil spring disposed within the tubular shotgun magazine at the distal end and having an inner diameter, and a follower disposed within the tubular shotgun magazine proximal the magazine coil spring. In some embodiments, the follower of the system for improving shotgun performance includes a cylindrical follower body configured to slide within the tubular magazine, the body having a cavity disposed axially and open at a distal end, a follower spring disposed within the cavity, and a follower tail connected to the body at the distal end of the cavity and extending toward the end of the magazine, the follower tail configured to slide into the cavity when compressed. 
         [0013]    In another embodiment, a device for use in a tubular shotgun magazine having a distal end and a proximal end and having a magazine coil spring disposed within the tubular shotgun magazine at the distal end and having an inner diameter includes a cylindrical follower body configured to slide within the tubular magazine, the body having a cavity disposed axially and open at a distal end, a follower spring disposed within the cavity, and a cylindrical follower tail having a diameter less than the inner diameter of the magazine spring and configured to compress the follower spring when pushed into the cavity, the follower tail extending toward the distal end of the magazine. 
         [0014]    Additional features and advantages of exemplary implementations of the disclosure will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by the practice of such exemplary implementations. The features and advantages of such implementations may be realized and obtained by means of the instruments and combinations particularly pointed out in the appended claims. These and other features will become more fully apparent from the following description and appended claims, or may be learned by the practice of such exemplary implementations as set forth hereinafter. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]    In order to describe the manner in which the above-recited and other advantages and features of the disclosure can be obtained, a more particular description of the disclosure briefly described above will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings. For better understanding, the like elements have been designated by like reference numbers throughout the various accompanying figures. Understanding that these drawings depict only typical embodiments of the disclosure and are not therefore to be considered to be limiting of its scope, the disclosure will be described and explained with additional specificity and detail through the use of the accompanying drawings in which: 
           [0016]      FIG. 1  is an exploded view of an embodiment of a compression follower. 
           [0017]      FIG. 2  is a top view of an embodiment of a compression follower body. 
           [0018]      FIG. 3A  is a side view of an assembled compression follower according to an embodiment of the present disclosure. 
           [0019]      FIG. 3B  is a cut-away side view of an assembled compression follower. 
           [0020]      FIG. 4  is a close up of a connection between a follower body and a follower tail. 
           [0021]      FIG. 5  is an exploded view of another embodiment of a compression follower. 
           [0022]      FIG. 6  is a cut-away side view of assembled compression follower according to another embodiment of the present disclosure. 
           [0023]      FIG. 7  is a side view of the interface between a compression follower tail and a magazine spring. 
           [0024]      FIG. 8A  is a cut-away view of a prior art follower in use. 
           [0025]      FIGS. 8B-8C  is a cut-away view of an embodiment of a compression follower in use. 
           [0026]      FIG. 8D  is a cut-away view of a prior art follower in use at the maximum capacity of a tubular magazine. 
           [0027]      FIGS. 8E-8F  is a cut-away view of an embodiment of a compression follower in use at the maximum capacity of a tubular magazine. 
           [0028]      FIG. 9  is an isometric view of another embodiment of a compression follower body. 
           [0029]      FIG. 10A  is an isometric view of another embodiment of a compression follower body including a receptacle area. 
           [0030]      FIG. 10B  is a cut-away side view of a compression follower body including a receptacle area. 
           [0031]      FIG. 11A  is a cut-away view of a prior art follower in use. 
           [0032]      FIGS. 11B-11C  is a cut-away view of another embodiment of a compression follower in use at the maximum capacity of a tubular magazine. 
       
    
    
     DETAILED DESCRIPTION 
       [0033]    One or more implementations of the present disclosure relate to ammunition storage and delivery in firearms. More particularly, one or more implementations of the present disclosure relate to the delivery of shotgun shells from a tubular magazine to a firing chamber by a follower and a magazine spring. 
         [0034]    Referring to  FIG. 1 , a compression follower according to the present disclosure includes, generally, a follower body  100 , a spring  200 , and a follower tail  300 . The follower body  100  may be generally cylindrical in shape with a diameter that substantially matches but is smaller than the diameter of a tubular magazine. The follower body need not be cylindrical, however. The follower body may be an octagon, hexagon, pentagon, or other polygon in cross-section. In the case of a polygonal follower body, the diameter of the circle ascribed by the vertices of the polygon should substantially match but be smaller than the diameter of a tubular magazine. References to “diameter” hereinafter should be understood to encompass polygons ascribing circles of such diameter. 
         [0035]    The terms “approximately”, “about”, and “substantially” as used herein represent an amount close to the stated amount that still performs a desired function or achieves a desired result. For example, the terms “approximately”, “about”, and “substantially” may refer to an amount that varies within less than 10% of, within less than 5% of, within less than 1% of, within less than 0.1% of, and within less than 0.01% of the stated amount. In the present example, the follower body should have a diameter that closely matches the diameter of the inner wall of the magazine, but may vary dependent on the length of the follower body. More specifically, a longer body is less likely to rotate in the magazine and the diameter of the body may be smaller in relation to the magazine diameter while rotating less, and thereby reducing the chance of ammunition delivery failure. In an embodiment, the ratio of follower body length to follower body diameter (“L-D ratio”) is greater than about 1. In another embodiment, the L-D ratio is less than about 1. In yet another embodiment, the L-D ratio is less than about 0.8. In yet another embodiment, the L-D ratio is less than about 0.5. 
         [0036]    The compression follower may be adapted to work with a variety of gauges, such as 10, 12, 16, 20, 28, 0.410, or other gauge. An outer diameter of the body may be such that the body can slide freely within the magazine but not turn sideways. The follower body and tail may be made of stainless steel, aluminum, Delrin® and/or any other machinable material. In addition, the follower may include a coating to increase wear resistance and/or decrease friction with the magazine. 
         [0037]    Referring now to  FIG. 2 , shotguns may be used in situations that allow dirt and debris to enter the magazine, either during transport or during the loading process of the firearm. Prior art followers can jam due to debris in the magazine tube lodging between the interior wall of the magazine and the follower. The body may have longitudinal grooves  102  in the outer wall  104  of the body to allow the compression follower to move past debris. In addition, the grooves  102  in the body may accommodate the installation of the compression follower into Remington® stock tubular magazines or similar magazines. The grooves  102  may be flat, stepped, concave, convex, may vary in shape and/or curvature along their length, or may be otherwise shaped. 
         [0038]    A compression follower may include additional openings or apertures to reduce the weight of the follower or to aid in machining, tooling, and/or manufacture of the follower. For example, as in the embodiments shown in  FIGS. 9 and 10 , a follower body  400  may include an opening or aperture at the proximal surface of the proximal end  428 . 
         [0039]      FIG. 3A  depicts an assembled compression follower  10 . A proximal end  302  of the follower tail may be disposed or partially disposed within a distal end  106  of the follower body, with the spring  200  disposed therebetween. 
         [0040]    As shown in  FIG. 3B , the follower body  100  has a cavity  108  that is open at a distal end  110 . The distal end  110  of the cavity  108  may have a lip or flange  112 . When the follower is assembled, the compression spring  200  may be disposed within the cavity  108  and configured to push the follower body  100  and follower tail  300  apart. In the illustrated embodiment, an expansion force is supplied by a coil spring, but an expansion force may be applied to the follower body  100  and follower tail  300  by other types of springs (e.g., leaf springs), pistons, or other resilient and/or elastic members, expansion devices, or combinations thereof. 
         [0041]    A proximal end  202  of the spring may mate with a recess  114  in the cavity  108  to hold the spring  200  in line with the axis of the follower body  100  and tail  300 . For example, the spring  200  may be press fit into the recess  114 , such that the proximal end  202  of the spring is retained within the recess  114  or there may be a post (not shown) in the proximal end  116  of the cavity  108  configured to retain and align the proximal portion  202  of spring. In other embodiments, a spring may be joined to a cavity of a follower body by adhesives, welding, clamps, pins, or other means of securing a spring in position. 
         [0042]    As shown in  FIG. 4 , a distal end  204  of the spring  200  may mate with a recess  304  in the follower tail  300 . The follower tail  300  may have an outer diameter less than an inner diameter of the cavity  108  in the follower body  100  such that the follower tail  300  may slide into the follower body  100  when the device is compressed. The follower tail  300  may include one or more tabs  306  to enable a press or snap fit between the compression follower body  100  and the compression follower tail  300 . For example, the one or more tabs  306  may be configured to engage with or abut against a lip or flange  112  of the follower body  100  to stop further movement of the follower tail  300  as the follower tail  300  is pushed toward the distal end  106  of the follower body by the spring  200  and/or is pushed out of the cavity  108 . In other embodiments, other stops may be used in order to maintain the follower tail  300  in position within the follower body  100  and/or to prevent dissociation of the follower tail  300  and follower body  100 . For example, pins, braces, latches, snap rings, or a combination of these or other stops may be employed. 
         [0043]    The follower tail  300  may also be striated, channeled, fluted, or otherwise slotted to aid in the press or snap fit, as well as reduce the weight of the follower. Reducing the weight of the follower can be advantageous because it reduces the swing weight of the firearm and can improve handling of the firearm. The connection of the tail  300  to the body  100  may also include a threaded cap, clips, or other retention devices or combinations thereof to ensure the tail  300  cannot slide out of the body  100 . 
         [0044]    In a particular embodiment, as shown in  FIGS. 5 and 6 , a compression follower in accordance with the present disclosure may include a follower body  400 , a spring  500 , and a follower tail  600 .  FIG. 5  depicts an exploded view of such an embodiment. In the embodiment illustrated in  FIG. 5 , for example, a follower body  400  includes one or more key members  418  extending from a distal surface of the follower body  400  (see also  FIG. 9 ). The one or more key members  418  may be uniform in size and shape and may be equally radially spaced along the distal end  406  of the follower body  400 , as shown in  FIGS. 5 and 6 . In other embodiments, one or more key members may not be evenly radially spaced, or may be non-uniform in size and shape. The one or more key members  418  preferably extend a distance radially inward from the distal end  406  of the follower body  400 , and are configured to fit into and mate with one or more keyways  612  included in a follower tail  600 . 
         [0045]    The follower tail  600  may include one or more keyways  612  configured to receive the one or more key members  418  of the follower body  400 . For example, a keyway  612  may include an opening  618  at the proximal end  602  of the follower tail  600  such that the keyway  612  extends all the way through the proximal end  602  of the follower tail  600 , and such that a key member  418  may be inserted into the keyway  612  at the keyway opening  618 . A keyway  612  may also include a locking section  614  configured to maintain the position of a key member  418  within the locking section  614  and away from an opening  618  in the keyway  612 . For example, a keyway  612  may extend toward a distal end  610  of the follower tail  600  before turning or angling around at an angled section  616  and extending back toward the proximal end  602  of the follower tail  600  to define a locking section  614 . A locking section  614  of a key member  612  does not extend fully through the proximal end  602  of the follower tail  600 , such that a key member  418  within the locking section  614  cannot pass through the proximal end  602  of the follower tail  600  without passing back through the angled section  616  and out of the keyway opening  618 . 
         [0046]      FIG. 6  illustrates an assembled compression follower. The proximal end  602  of the follower tail  600  may be disposed or partially disposed within a distal end  406  of the follower body  400 , with the spring  500  disposed between the follower body  400  and follower tail  600 . The follower tail  600  may have an outer diameter less than an inner diameter of a cavity  408  of the follower body  400  such that the follower tail  600  may slide into the follower body  400  when the device is compressed. When such a compression follower is assembled, the compression spring  500  may be disposed within the cavity  408  of the follower body  400  and configured to push the follower body  400  and follower tail  600  apart. For example, a spring  500  may be joined to the follower body  400  and/or follower tail  600  by press fitting into a recess of the follower body  400  and/or a recess of the follower tail  600 , as described above in relation to other embodiments (see, e.g.,  FIGS. 3B and 4 ). 
         [0047]    In the particular embodiment shown in  FIGS. 5 and 6 , the follower body  400  may be joined to the follower tail  600  by inserting one or more key members  418  of the follower body  400  into the one or more keyways  612  configured for receiving the corresponding one or more key members  418 . The follower body  400  and the follower tail  600  may then be positioned relative to one another (e.g., rotated) such that the one or more key members  418  pass through the one or more angled sections  616  and are positioned within the one or more locking sections  614 . In this configuration, the spring  500  may force the follower body  400  and the follower tail  600  apart, and as the device compresses and expands, the follower body  400  will remain joined to the follower tail  600  by the position of the one or more key members  418  within the locking section(s)  614  of the one or more keyways  612 . 
         [0048]    As shown in  FIG. 7 , the outer diameter of the follower tail  300  may also be less than that of an inner diameter of a magazine spring  42  to enable the tail  300  to extend through the center of the magazine spring  42 , thereby encouraging axially aligned compression and expansion of the magazine spring  42  and aligning the compression follower  10  axially within the magazine. In one embodiment, the ratio of follower body length to follower tail length (“B-T ratio”) is less than about 1. In another embodiment, the B-T ratio is greater than about 1. In yet another embodiment, the B-T ratio is greater than about 1.5. In yet another embodiment, the B-T ratio is greater than about 2. In yet another embodiment, the B-T ratio is greater than about 3. 
         [0049]    The follower tail  300  may also be tapered toward a distal end to more reliably expand into the magazine spring  42  without catching on the coils. The tail  300  may alternatively include a plurality of pieces of decreasing diameter joined in a manner similar to the way in which any of the components of the other embodiments are joined, as previously described (e.g., in a manner similar to the way in which the tail  300  is connected to the body  100 ), to create a telescoping tail. In an extended state, the plurality of pieces may be extended by the spring  200 . The plurality of pieces may be connected as described above in relation to connecting a follower body to a follower tail (e.g., using a snap or press fit with a lip or flange or by locking keyways or by other retention devices or combination thereof). In a compressed state, the plurality of pieces would each slide into the cavity  108  in an axially aligned, concentric relationship. A telescoping tail would enable longer extension and, in addition, would intrinsically include the advantageous tapering of the tail previously mentioned. 
         [0050]    Referring to  FIGS. 8A-8C , a compression follower  10  (shown compressed in  FIG. 8B  and expanded in  FIG. 8C ) may replace a standard follower  20  (shown in  FIG. 8A ) in a tubular magazine  40 . The compression follower  10  is disposed within the tubular magazine  40  in an expanded form, similar to the prior art “performance follower”  30  with a rigid follower tail, until the magazine  40  is loaded to capacity. As shells  50  are loaded into the magazine  40 , the shells  50  may push against the follower body  100 , and the follower body  100 , in turn, may push against and compress the magazine spring  42 . 
         [0051]    As can be seen in  FIGS. 8D-8F , upon insertion of the final shell  52  into the magazine  40 , the follower tail  300  may contact a magazine cap  44  or other end of the magazine  40 . However, upon contacting the end of the magazine  44 , the compression follower tail  300  may slide into the compression follower body  100 , compressing to the size of the prior art “standard follower”  20  and allowing the full magazine capacity. The tail  300  need not compress fully into the follower body  100 , but only enough to permit loading of the full capacity of the magazine. 
         [0052]    Likewise, the compression follower  10  operates to expand upon delivery of a first shell from the magazine to the firing chamber. When the first (final loaded) shell is delivered to the firing chamber and the line of ammunition moves away from the forward end of the magazine, the compression follower spring  200  expands and the compression follower tail  300  extends. Upon extension, the tail slides into the inner diameter of the magazine spring  42 , and the configuration returns to that of  FIGS. 8A-8C . 
         [0053]      FIG. 9  illustrates another view of an embodiment of a follower body  400  according to the present disclosure. In the embodiment shown in  FIG. 9 , the distal end  406  of the follower body  400  includes a collar section  420  that is substantially solid (e.g., is substantially free of cutouts, voids, etc.). In other embodiments, the collar section  420  may not be substantially flat and/or substantially solid. In the embodiment illustrated in  FIGS. 10A and 10B , for example, the collar section  420  includes a circumferential cutaway or recess (e.g., a trepan cut), extending from the distal end  406  of the follower body  400  a distance toward a proximal end  428  of the follower body  400 , thereby forming a receptacle area  422  disposed between an outer collar  424  and an inner collar  426  of the follower body  400 . 
         [0054]    The cutaway or recess forming the receptacle area  422  may extend from the distal end  406  of the follower body  400  to the proximal end  428  of the follower body  400  without passing completely through the proximal end  428 . For example, the receptacle area  422  may be as deep as possible while still maintaining the structural integrity of the follower body  400 , such as extending through about 80% or more of the length of the follower body  400 . Alternatively, the cutaway or recess forming the receptacle area  422  may extend only partially through the length of the follower body  400 , such as extending through less than about  80 % of the length in some embodiments, or less than about  65 % in other embodiments. In other embodiments, the receptacle area  422  may extend less than about 50% or even less than about 35%. In yet other embodiments, the receptacle area  422  may extend through about 20% of the length of the follower body  400  or less. 
         [0055]      FIGS. 11A-11C  illustrate a compression follower (shown compressed in  FIG. 11B  and expanded in  FIG. 11C ) that may replace a standard follower (shown in  FIG. 11A ) in a tubular magazine. An embodiment of a compression follower may include a follower body  400  including a receptacle area  422  configured to receive a magazine spring  42  or portion thereof. As described above in relation to  FIGS. 8A and 8B , as shells  50  are loaded into the magazine  40 , the shells  50  push against the follower body  400 , and the follower body  400 , in turn, may push against and compress the magazine spring  42 . Upon insertion of the final shell  52  into the magazine  40 , the follower tail  600  may contact a magazine cap  44  or other end of the magazine  40 , whereupon the follower tail  600  may slide into the follower body  400 , compressing the length of the compression follower device. In the particular embodiment shown in  FIG. 11 , the magazine spring  42  may also enter and be positioned within the receptacle area  422  of the follower body  400  and/or may be secured or attached therein. In some embodiments, this may allow further compression of space within the magazine  40  and ability to reach full magazine capacity. 
         [0056]    The present disclosure may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the disclosure is, therefore, indicated by the appended claims rather than by the foregoing description. All changes that come within the meaning and range of equivalency of the claims are to be embraced within their scope. Additionally, any combination of the featured disclosed in any of the foregoing embodiments can be combined, such that components and elements from one embodiment may be incorporated into and/or replace elements from any of the other embodiments described herein.