Patent Publication Number: US-9835395-B2

Title: Apparatus and method for reloading firearm magazines

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation and claims the benefit of U.S. patent application Ser. No. 14/177,353, filed on Feb. 11, 2014, entitled “APPARATUS AND METHOD FOR RELOADING FIREARM MAGAZINES,” which claims the benefit of United States Provisional Patent Application No. 61/762,973 filed on Feb. 11, 2013, entitled “APPARATUS AND METHOD FOR MECHANICALLY INTERCHANGING FIREARM MAGAZINES FACILITATING POSITIVE USER CONTROL,” and U.S. Provisional Patent Application No. 61/893,861 filed on Oct. 21, 2013, the disclosures of which are incorporated herein by reference in their entireties. 
    
    
     FIELD OF THE PRESENT INVENTION 
     The present invention relates generally to the field of firearms, specifically to a firearm that is configured to provide the storage and automatic or semi-automatic reloading of one or more spare magazines after an active magazine is removed or ejected from the firearm. 
     BACKGROUND INFORMATION 
     Many modern firearms used for combat or sporting activities are equipped with magazines capable of holding a plurality of cartridges. Such magazines can facilitate and simplify loading of individual cartridges into a firing chamber. A magazine is typically released manually from the firearm before another magazine with additional cartridges can be inserted into the firearm, e.g., to continue firing. For example, as described in U.S. Pat. No. 5,676,241 issued to Christophe Degoix et al., reloading a magazine-adapted firearm typically involves pressing a magazine release button on the side of a magazine well of the firearm to release the magazine, pulling the magazine clear of the magazine well, storing it for later reuse, grasping a new magazine with cartridges in it, inserting the new magazine into the magazine well until it clicks into place, and then chambering a cartridge from the new magazine. 
     Typically, spare magazines may be carried in a protective pouch attached to a user&#39;s belt or carried in the user&#39;s pocket or the like. Certain firearms may also be configured to carry one or more spare magazines affixed to other parts of the firearm for convenience. However, the removal and insertion of additional magazines may present safety concerns for the user. For example, during reloading in a combat situation, a soldier or law enforcement official may be exposed to enemy fire and unable to continue firing until the reloading process is completed. As another example, an accidental discharge of the firearm may occur during a botched reloading procedure, e.g. with magazine-fed firearms. A prolonged period for reloading magazines can also affect, e.g., the overall firing speed of competitive skeet shooters. 
     Various systems have been developed to expedite and ease the carrying and/or reloading of additional magazines into a firearm. For example, multiple magazine holders can couple together two or more magazines so that a combatant or sportsman will have more than one magazine readily available for use with the weapon. Such holders can include, for example, magazines that are welded or otherwise affixed together. For example, a clip joining device for holding two clips end to end is described, e.g., in U.S. Pat. No. 4,685,238 issued to Schoepflin, a box-like protective device attachable to the weapon is described, e.g., in U.S. Pat. No. 4,484,404 issued to Johnson, and magazine doublers that are formed as a dual magazine holder to provide users the ability to quickly and efficiently reload rifles with a second magazine are described, e.g., in U.S. Pat. No. 7,497,043 issued to Clifton, Jr. et al. None of these references describe a firearm system that provides the ability to store and automatically or semiautomatically introduce spare magazines into the active magazine well of a weapon. 
     Accordingly, there is a need for a firearm capable of storing one or more spare firearm magazines that further facilitates the automatic or semi-automatic exchange of magazines into the active magazine well of the firearm upon the partial or full exhaustion of cartridges from the active magazine. 
     SUMMARY OF EXEMPLARY EMBODIMENTS 
     Exemplary embodiments of the present disclosure provide firearms with a magazine track. One exemplary embodiment of the disclosure, as described below, is a lower receiver of an AR-15 style firearm that stores a plurality of individual ammunition magazines, i.e. reserve magazines, in a magazine track and allows the user to successively reload the AR-15 style firearm by automatic or semi-automatic means. The magazine track starts at the muzzle end of the AR-15 style firearm and runs parallel to the axis of the AR-15 style firearm. The magazine track is a storage arrangement comprised of a structure that includes two C-shaped grooves or channels separated by a space with the open sides of the C-shaped grooves facing each other. The reserve magazines are made suitable for insertion into the magazine track by modifying conventional magazines with a fitted magazine adapter. 
     As reserve magazines are initially inserted into the magazine track for storage, they compress a compression spring inside the magazine track and are stopped from being pushed back out by a reserve magazine catch. The reserve magazine catch allows magazines to be loaded into the magazine track and prevents magazines from leaving the magazine track until the reserve magazine catch is moved to a release position. The AR-15 style firearm with this disclosure is capable of successively reloading each individual reserve magazine in the magazine track into an active magazine well through semi-automatic means carried out by moving a structure or part (a “pump”). 
     In one exemplary embodiment, the pump, which may be grasped and manually moved by a user, slides along the axis of the AR-15 style firearm, initially toward the buttstock and then back toward the muzzle to its starting position. Such movement of the pump provides the force actuating the movement of other parts to facilitate the magazine reloading process. The action of the pump moves two sets of interconnected lever arms with pivot points, one set on the left and right side of the lower receiver from a user&#39;s perspective. The first movement of the pump extends the ends of four levers (and the mirror-image set), which have dowels on them (and the mirror-image set) so that the dowels are under the active magazine well and aligned horizontally with the magazine track. After the levers reach their extended position, the reserve magazine catch is released and a reserve magazine is then moved underneath the active magazine well by the force of a compression spring. The reserve magazine is held in place under the active magazine well by the dowels (and the mirror-image set), which fit into the magazine adapter slot. The reserve magazine that was next in line toward the muzzle is also pushed toward the buttstock by the compression spring but is stopped by the reserve magazine catch, which has automatically returned to its initial position. 
     When the pump is pushed forward to its original position, the reserve magazine positioned under the active magazine well is then forced up into the active magazine well by the lever arms with dowels as they are moved back up by the pump movement. The reserve magazine movement has enough upward force to engage the active magazine catch &amp; release before the lever arms are returned to their original position outside the active magazine well. This completes a semi-automatic reloading process of a magazine that is then capable of being used to continue firing and enabling positive user control of the firearm. 
     One advantage of the embodiments of the disclosure is that semi-automatic switching results in a magazine reload without the user having to perform a traditional manual exchange by hand of the spent active magazine with a full reserve magazine. 
     In an exemplary embodiment, the user will hold the AR-15 style firearm by the pump and slide the pump back and forward similar to how one would pump certain styles of shotguns. The process results in the user obtaining positive control because the user may focus exclusively on the target during the reloading process providing for superior safety through better situational awareness and also ensures that the firearm is never pointing at anything the user is not intending to shoot. 
     Another advantage of the embodiments of the disclosure is that unlike a single high capacity magazine, the present embodiment of the disclosure does not chain, latch or join in any way, the plurality of individual magazines together in such a fashion so as to continuously and directly feed the cartridges of the AR-15 style firearm. Each reserve magazine is still reloaded into, dispenses ammunition and is ejected out of the AR-15 style firearm separately. The individual magazines used in the AR-15 style firearm may be adapted to store the legally allowable amount of cartridges per individual magazine in order to remain complaint with applicable state law for civilian use or may be adapted exclusively for military or law enforcement use by adjusting the capacity of the individual magazines. 
     Another advantage of the embodiments of the disclosure is that the present embodiment will work with one or a plurality of magazines. If only one magazine operation is desired it may be inserted into the active magazine well  141  and pressed upward until it is held by the active magazine catch &amp; release  144 . The present embodiment may also be constructed such that it is compatible with fixed as well as detachable magazines, including using a mechanism commonly known in the art as a “bullet button.” 
     These and other objects, features and advantages of the present invention will become apparent upon reading the following detailed description of exemplary embodiments of the present invention, when taken in conjunction with the appended drawings and claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Further objects, features and advantages of the present invention will become apparent from the following detailed description taken in conjunction with the accompanying figures showing illustrative embodiments, results and/or features of the exemplary embodiments of the present invention, in which: 
         FIG. 1  shows an exemplary exploded side view of an AR-15 style firearm in accordance with certain embodiments of the present disclosure; 
         FIG. 2A  is an inverted perspective view of the exemplary firearm shown in  FIG. 1  with a pump removed for clarity; 
         FIG. 2B  is angled sideways perspective view of the bottom of the exemplary firearm shown in  FIG. 2A ; 
         FIG. 3  shows an angled perspective view of a conventional magazine and a magazine adapter, in separated and assembled configurations, in accordance with certain embodiments of the present disclosure; 
         FIG. 4A  is a cross-sectional end view of the exemplary firearm shown in  FIG. 2A ; 
         FIG. 4B  is an angled perspective view of the side and top of the magazine track and its associated structures in accordance with certain embodiments of the present disclosure; 
         FIG. 5  is a perspective end view of the magazine track showing a compression spring and follower that can facilitate storage and reloading of reserve magazines; 
         FIG. 6  is a perspective close-up view of a portion of the magazine track and associated reserve magazine release lever in accordance with certain embodiments of the present disclosure; 
         FIG. 7  is a side view of an exemplary AR-15 style firearm with the pump removed for clarity to show an exemplary lever arrangement for reloading spare magazines in accordance with certain embodiments of the present disclosure; 
         FIG. 8  is a cross-sectional end view from the muzzle end showing the shape of the pump and receiving grooves in the magazine track; 
         FIG. 9A  is a side view of the exemplary firearm shown in  FIG. 7  where the lever arm arrangement is extended before a reserve magazine has been released; 
         FIG. 9B  is a close-up view of the exemplary lever arrangement showing a reserve magazine release trigger contacting a reserve magazine release lever; 
         FIG. 10A  is another close-up view of the exemplary lever arrangement showing a set screw contacting the reserve magazine release lever; 
         FIG. 10B  is a side view of the exemplary firearm shown in  FIG. 9A  where a reserve magazine has been released and moved onto a dowel at one end of the lever arm arrangement; 
         FIG. 10C  is a side view of the exemplary firearm shown in  FIG. 10B  with the pump in place, showing a reserve magazine positioned in the active magazine well lever arm; 
         FIG. 10D  is angled perspective view of the exemplary firearm shown in  FIG. 10C  showing the reserve magazine after it has slid off the magazine track and has engaged with dowels associated with the lever arrangement; 
         FIG. 11A  is a side view of the exemplary firearm shown in  FIG. 10C  with the pump returned to a forward position and the reserve magazine inserted into the active magazine well; 
         FIG. 11B  is angled close-up perspective view of a portion of the exemplary firearm shown in  FIG. 11A ; 
         FIG. 12  is a perspective view of an exemplary firearm that includes an automatic exchange arrangement for reloading spare magazines in accordance with further embodiments of the present disclosure; 
         FIG. 13  is an end perspective view of the inside of the magazine track showing certain components of the exemplary automatic exchange arrangement illustrated in  FIG. 12 ; 
         FIG. 14  is another end perspective view of the inside of the magazine track and portions of the exemplary automatic exchange arrangement illustrated in  FIG. 13 , where a magazine lift mechanism has risen and reloaded a reserve magazine (not shown) into the active magazine well; and 
         FIG. 15  is a side view of an exemplary ball bearing clutch that can be used with the automatic exchange arrangement illustrated in  FIGS. 12-14 . 
     
    
    
     Throughout the drawings, the same reference numerals and characters, unless otherwise stated, are used to denote like features, elements, components, or portions of the illustrated embodiments. Similar features may thus be described by the same reference numerals, which indicate to the skilled reader that exchanges of features between different embodiments can be done unless otherwise explicitly stated. Moreover, while the present invention will now be described in detail with reference to the figures, it is done so in connection with the illustrative embodiments and is not limited by the particular embodiments illustrated in the figures. It is intended that changes and modifications can be made to the described embodiments without departing from the true scope and spirit of the exemplary embodiments of the present invention as defined by the appended claims. 
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     An exemplary firearm in accordance with certain embodiments of the present disclosure is shown in  FIG. 1 . The firearm  101  is an AR-15 style firearm, although other types of firearms can also be used with embodiments of the disclosure. The AR-15 style firearm  101  includes three major components as shown in  FIG. 1 : a lower receiver  120 , an upper receiver  110 , and a buttstock  102 . The exemplary upper receiver can include a muzzle  111  (shown separated from the upper receiver  110  in  FIG. 1 ), a barrel  112 , and a bolt mechanism  113 . The lower receiver  120  can include a pistol grip  121 , a trigger component  122 , an active magazine release button  143 , an active magazine well wall  142 , and an active magazine  140  positioned in the active magazine well  141 . The active magazine  140  is a magazine that can contain a plurality of cartridges (not shown) and feed the cartridges sequentially into the firing chamber. 
     As used herein, the term “button” can refer to any component that may be acted upon by a user to initiate one or more mechanical or automated actions carried out by one or more mechanisms or arrangements in the apparatus being described. For example, a button can include, but is not limited to, a conventional protrusion that can be depressed by, a switch, a lever, e.g. that may rotate around a pivot, or a knob, handle, or the like that may be configured to twist or slide in a track or guide. A button can optionally be configured to return to an initial or resting position when released, e.g., by the action of a spring, a resilient material, a mechanical arrangement, or the like. 
     Unlike conventional firearms, the lower receiver  120  of the AR-15 style firearm  101  includes an exemplary pump  130 . Because many firearms (such as the AR-15 style firearm) may have a standardized modular design, embodiments of the present disclosure can include or provide a lower receiver  120  that matches the industry standard dimensions for interconnection, allowing it to connect to compatible upper receivers  110  and/or buttstocks  102  from any manufacturer that follows such standard dimensions at the relevant points. 
     Providing one or more reserve magazines in the present invention may be performed in a variety of ways. In one exemplary embodiment of a storage arrangement, shown in  FIG. 2A , reserve magazines  210  can be stored in the magazine track  200 . For example, the lower receiver  120  can optionally be inverted (for ease of handling), and a reserve magazine  210  can be stored onto the magazine track  200  by positioning the reserve magazine  210  partially in the active magazine well  141  such that a magazine adapter  212  on the reserve magazine  210  (shown in  FIG. 3 ) aligns with grooves provided along at least a portion of the length of the magazine track  200 . The reserve magazine  210  can then be slid into the magazine track  200  towards the distal or muzzle end of the magazine track  200 , pushing against a sliding follower  201  and compression spring  202  that may be provided in the magazine track  200 . The distal end of the compression spring  202  can be held in the magazine track  200 , e.g., by providing a pump wall  501  or the like at a distal end of the magazine track  200 . The reserve magazine  210  can be retained in the magazine track  200 , e.g., by a reserve magazine catch  502  (shown in  FIG. 5 ) or other similar retention arrangement. 
       FIG. 2B  shows the exemplary lower receiver  120  of  FIG. 2A  after a third reserve magazine  210  has been stored in the magazine track  200 , with an active magazine  140  being positioned for insertion into the active magazine well  141 . The active magazine  140  can be retained in the active magazine well  141 , e.g., by a conventional magazine catch-and-release arrangement comprised of an active magazine catch and release  144 , which can be activated by an active magazine release button  143 , or the like. 
     As shown in  FIG. 3 , the reserve magazine  210  can include a conventional magazine  211  and a magazine adapter  212  that fits around the conventional magazine  211 . The magazine adapter  212  can be affixed to the conventional magazine  211 , e.g., by specifying the shape of the central opening of the magazine adapter  212 , by friction, by an adhesive substance, by welding the two components together, and/or by spacers or protrusions (not shown) provided on the reserve magazine  210  and/or the conventional magazine  211 . The magazine adapter  212  may be comprised of a single piece or multiple pieces that can be affixed to the conventional magazine  211 . In further embodiments of the disclosure, the reserve magazine  210  can be formed as a single unit that includes the overall shape and functionality of the assembled conventional magazine  211  and a magazine adapter  212 . 
     The magazine adapter  212  can be provided with edge protrusions  215  that run along the lateral sides of the magazine adapter  212 . The edge protrusions  215  can be shaped to fit into corresponding magazine track grooves  217  provided along the inside walls of the magazine track  200  (shown in  FIGS. 4A and 4B ). Such exemplary configuration can facilitate a longitudinal translation or sliding of the reserve magazine  210  along at least a portion of the magazine track  200 , as well as a retention of the reserve magazine(s)  210  within the magazine track  200 . These edge protrusions  215  can further define magazine adapter slots  216  that can run along the outer edges of the magazine adapter  212 , as shown in  FIG. 3 . These exemplary features of the magazine adapter  212  can be configured to interact with other components of the exemplary AR-15 style firearm  101  to facilitate automatic or semi-automatic reloading of stored reserve magazines  210  into the active magazine well  141 , as described in more detail herein. 
       FIG. 4A  shows an end view of a lower receiver  120 , where a reserve magazine  210  with the magazine adapter&#39;s two edge protrusions  215  is located within the magazine track grooves  217  of the magazine track  200 . The exemplary magazine track  200  shown in  FIG. 4B  can include the magazine track grooves  217 , active magazine well wall  142 , and longitudinal pump grooves  435  that may run longitudinally along at least a portion of the outer sides of the magazine track  200 . These pump grooves  435  can facilitate lateral translation of the pump  130  along the pump grooves  435  to facilitate reloading of reserve magazines  210  in certain embodiments of the present disclosure. 
     Some components of the exemplary AR-15 style firearm  101  may be formed from a single piece of material, whereas other components may be formed separately and attached (as appropriate) permanently or with fasteners. For example, the active magazine well wall  142  shown in  FIG. 4B  may be formed as part of the magazine track  200 , or optionally it may be formed as a separate component and affixed to the magazine track  200 . Different structural options, configurations, and details may be used to provide the various functions of the exemplary embodiments described herein. Selection of such options for a particular embodiment can be based on various reasons including, but not limited to, improved component and manufacturing costs, and ease of assembly or repair of broken or worn parts. For example, a height-adjustment arrangement that can set how deep a reserve magazine is inserted into the active magazine well may be included. This height-adjustment arrangement may include a replaceable shim adjacent to the magazine track  200  such that shims of various shapes or thicknesses can be used to control the depth to which the reserve magazine  210  is moved into the active magazine well  141 . 
       FIG. 5  is a view of the inside of the exemplary magazine track  200  looking towards the distal end thereof. A follower  201  can be configured to slide within the magazine track grooves  217  in the magazine track  200 . The follower  201  may be generally pushed toward the proximal end of the magazine track  200 , e.g., by a compression spring  202  also located within the magazine track  200 , where the distal end of the compression spring  202  may be fixed to or constrained by the pump wall  501 . In certain embodiments, the follower  201  can be formed of an ultra-high molecular weight polyethylene (“UHMW-PE”). A reserve magazine catch  502  can be configured to prevent the follower  201  from sliding out of the proximal end of the magazine track  200 . As a first reserve magazine  210  is inserted into the magazine track  200  and pushes against the follower  201 , the follower  201  may slide back into the magazine track  200  toward the pump wall  501 , thereby compressing the compression spring  202  and producing a force on the reserve magazine  210  directed towards the proximal end of the magazine track  200  and the active magazine well  141 . 
     Once pushed into the magazine track  200 , the reserve magazines  210  can be constrained from sliding out of the magazine track  200  and into the active magazine well  141 . For example, as shown in  FIG. 6 , a reserve magazine catch  502  may be provided near the proximal end of the magazine track  200 . The reserve magazine catch  502  can be configured to act as a one-way ratchet mechanism that allows the reserve magazines  210  to be pushed towards the distal end of the magazine track  200 . A reserve magazine release lever  601  can be pivotally coupled to the reserve magazine catch  502 , e.g., across a pivot point  610 , and an associated torsion spring or the like (not shown) can be provided such that the resting state of the magazine catch  502  can prevent the reserve magazines  210  from exiting the proximal end of the magazine track  200 , e.g., into the active magazine well  141 . If a reserve magazine  210  is being retained within the magazine track  200  by the reserve magazine catch  502 , another reserve magazine  210  may then be inserted into the magazine track  200  in the same fashion as the first. A further reserve magazine  210  that is stored after the first one will push against the previously inserted reserve magazine(s)  210  and further compress the compression spring  202 , e.g., until a particular portion of the further reserve magazine  210  passes the reserve magazine catch  502  that will then hold it within the magazine track  200 . 
     The magazine reloading process can be continued until the compression spring  202  is fully compressed and the follower  201  is at its farthest position away from the active magazine well  141 , which results in filling up the magazine track  200  as shown in  FIG. 7 . In this embodiment, enough room is left in the distal portion of the magazine track  200  (i.e., the portion closest to the muzzle end and pump wall  501  of the firearm) to allow space for the compressed compression spring  202  and follower  201  therein when the reserve magazines  210  are stored in the magazine track  200 . The magazine track  200  need not be filled to maximum capacity with reserve magazines  210  to use the firearm. 
     After the initial storing of reserve magazines  210  is completed, an active magazine  140  can be inserted into the active magazine well  141 , e.g., using conventional magazine loading procedures. For example, an active magazine  140  can be inserted into the active magazine well  141  and pushed upward toward the upper receiver  110  until it is held by the active magazine catch-and-release  144  on the lower receiver  120 , thereby making it the active magazine  140  as shown, e.g., in  FIG. 11A . 
     With an active magazine  140  in the active magazine well  141 , a conventional bolt catch-and-release  114  such as that shown in  FIG. 2A  can be activated. Once released by the bolt catch-and-release  114 , the bolt mechanism  113  in the upper receiver  110  can receive a cartridge (not shown) from the active magazine  140  and move it into a position for firing. If the initial loading process was begun without first pulling back and catching the bolt mechanism  113  on the upper receiver  110 , as is common, then this release step may be unnecessary. After some or all of the cartridges in the active magazine  140  have been fired, the magazine reloading procedure described below may begin. 
     For example, if an active magazine  140  is in the active magazine well  141 , it can first be removed from the active magazine well  141 . This can be done for a conventional AR-15 style rifle or the like by first pressing the active magazine release button  143  on the lower receiver  120 , thereby opening the active magazine catch-and-release  144  that holds the active magazine  140  in the active magazine well  141  to allow the active magazine  140  to be removed from the active magazine well  141  or fall out of the active magazine well  141  due to gravity. Releasing the active magazine release button  143  can return the active magazine catch-and-release  144  back into its standard closed position. Once the active magazine well  141  is empty, exemplary embodiments of the present disclosure can facilitate reloading of a reserve magazine  210  into the active magazine well  141  as follows. 
       FIG. 7  shows the exemplary AR-15 style firearm  101  with an empty active magazine well  141 , three reserve magazines  210  initially stored in the magazine track  200 , and exemplary lever arms  410 ,  411 ,  412 ,  413  that are pivotally coupled and located proximal to the active magazine well  141 . The pump  130  is not shown in  FIG. 7  to more clearly show the arrangement of the lever arms  410 ,  411 ,  412 ,  413 . 
       FIG. 1  shows the pump  130  from a side perspective in its starting position. It can be configured to translate laterally along the length of the magazine track  200 , e.g., toward the active magazine well  141  and back to its original position. Such translation can be guided by pump tongues  802 , which can be affixed to—or optionally formed as part of—the pump  130  and configured to fit into the pump grooves  435  provided on the outer sides of the magazine track  200  as shown in  FIG. 8 , to facilitate such sliding motion. The pump  130 , described in more detail below, may be physically constrained from sliding towards the active magazine well  141  if an active magazine  140  is present in the active well  141 . In certain embodiments, the pump  130  can be formed from an engineering plastic, a metal or alloy, a composite material, or the like. 
     An exemplary reloading procedure for reserve magazines  210  is now described in terms of certain exemplary levers, pivot points, and connections provided on one side of the lower receiver  120 . Embodiments of the present disclosure can include a mirror-image set of these levers, pivot points, and connections provided on the opposite side of the lower receiver  120 , which may perform the same functions of engaging and moving the reserve magazines  210  by engaging them on their opposite side of the AR-15 style firearm  101 . Such mirrored components can provide improved balance of mechanical functions, e.g., to reduce wear and/or stresses on components, and are visible in certain figures. 
     After removal of the active magazine  140  from the AR-15 style firearm  101 , movement of the pump  130  can initiate reloading of a reserve magazine  210  into the active magazine well  141 . For example, sliding the pump  130  to its furthest position towards the buttstock  102  can cause direct movement of the first lever arm  410  that is pivotally coupled to the pump  130  at its distal end through pivot  430 , as shown in  FIG. 9A . The movement of the first lever arm  410  in turn can move exemplary lever arms  411 ,  412 , and  413  from their initial (resting) positions shown in  FIG. 7  to the positions shown in  FIG. 9A . The first lever arm  410  is moved proximally toward the buttstock  102  by the pivoting pump connector  430 , and the proximal end of the first lever arm  410  will simultaneously move backward as well as downward, e.g., as shown by comparing  FIG. 7  with  FIG. 9A . The proximal end of first lever arm  410  is rotatably coupled by a pivot point  420  to the distal end of the second lever arm  411  and to the central portion of third lever arm  412 , as shown, e.g., in  FIGS. 9A and 9B . The proximal end of the second lever arm  411  is also rotatably coupled by another pivot point  420  to the central portion of the fourth lever arm  413  as also shown, e.g., in  FIGS. 9A and 9B . The distal ends of the third lever arm  412  and fourth lever arm  413  are each rotatably coupled to the lower receiver  120  by further pivot point  420 . 
     The exemplary configuration of the lever arms  410 ,  411 ,  412 ,  413 , pivoting pump connector  430  and pivot points  420  causes the upper/proximal ends of lever arms  412 ,  413  to move proximally (i.e. towards the buttstock  102 ) and downward when the pump  130  is translated toward the buttstock  102 , whereas the second lever arm  411  that is pivotally coupled to the central portions of lever arms  412 ,  413  remains substantially horizontal. This coordinated motion of the pump  130  and lever arms  410 ,  411 ,  412 ,  413  is illustrated by comparing  FIGS. 7, 9A and 9B . After this lateral movement of the pump  130 , shown in  FIG. 9 , the proximal/top ends of the third lever arm  412  and fourth lever arm  413  are at substantially the same height and can be configured to line up horizontally with the axis of the magazine track grooves  217  provided in the magazine track  200 . As shown in  FIG. 9B , fixed dowels  422 ,  423  are provided at the proximal ends of lever arms  412 ,  413 , respectively. The dowels  422 ,  423  protrude inward from the levers  412 ,  413  toward the magazine track grooves  217 . These dowels  422 ,  423  are horizontally aligned with the magazine track grooves  217  when the pump  130  is fully translated towards the proximal/buttstock end of the AR-15 style firearm  101 , such that when a reserve magazine  210  is pushed off the magazine track  200  in the next reloading step, the magazine adapter slots  216  will slide over dowel  422  and dowel  423  (and over their counterparts on the opposite side of the lower receiver  120 ) to position the reserve magazine  210  under the active magazine well  141 . 
     A further reloading step can be actuated at or near the end of the first proximal translation of the pump  130 . For example, as shown in  FIG. 10A , the third lever arm  412  can be provided with a reserve magazine release trigger  424  that is configured to push on the reserve magazine release lever  601  when the proximal end of the lever arm  412  is moved proximally as described herein. The reserve magazine release trigger  424  can optionally include an adjustable setscrew  426  or the like that can be adjusted to control the amount of force exerted on the reserve magazine release lever  601  when the lever arm  412  moves. The reserve magazine release lever  601  is coupled to the reserve magazine catch  502 , as shown in the exemplary configuration of  FIG. 6 . When the reserve magazine release lever  601  is pressed inward toward the center of the magazine track  200 , the reserve magazine catch  502  will move in the opposite direction around the pivot  610 , thereby moving the magazine catch  502  out of the magazine track groove  217 . Once the reserve magazine catch  502  is released in this manner, any reserve magazines  210  stored in the magazine track  200  will slide toward the active magazine well  141  due to the pressure of the compression spring  202 . With this movement, the reserve magazine  210  closest to the active magazine well  141  can be pushed out of the proximal end of the magazine track  200 , and the magazine adapter slots  216  can initially slide onto dowels  422  as shown, e.g., in  FIG. 10B . This first reserve magazine  210  can then continue to slide out of the magazine track  200  such that the magazine adapter slots  216  then slide onto dowels  422 ,  423 . The reserve magazine  210  will stop sliding when the magazine adapter  212  contacts the active magazine well wall  142 . Dowels  422  and  423  (and their mirror-image dowels) hold the reserve magazine  210  under the active magazine well  141  as shown in  FIG. 10B , preventing this magazine  210  from falling out of the active magazine well  141 . 
       FIG. 10C  shows perspective side view of the magazine adapter slot  216  that has slid onto the dowels  422 ,  423 , although only dowel  423  is visible beyond the proximal end of the pump  130  in this figure. The reserve magazine  210  that was pushed into the active magazine well  141  stops its lateral movement when it reaches the active magazine well wall  142 , which can be configured to extend downward to reach the level of the magazine adapter  212 . 
     In one exemplary embodiment, the active magazine well wall  142  and trigger components  122  may be modified from a conventional lower receiver design such that when the magazine adapter  212  contacts the active magazine well wall  142 , the reserve magazine  210  is positioned directly under the active magazine well  141 , such that the reserve magazine  210  can slide directly upward along the active magazine well wall  142  until it engages with the active magazine catch-and-release  144 . The reserve magazine catch  502  can return to a locked position after the first reserve magazine  210  exits the proximal end of the magazine track  200 , e.g., by the force of a return spring or the like, such that the reserve magazine catch  502  will prevent a next reserve magazine  210  from sliding out of the magazine track  200 . If a further reserve magazine  210  is stored in the magazine track  200 , it will also be prevented from exiting the magazine track  200  by the presence of the next reserve magazine  210 . 
       FIG. 10D  shows the exemplary AR-15 style firearm  101  with the pump  130  at the end of its first motion toward the buttstock  102  and the reserve magazine  210  held under the active magazine well  141 . A further motion of the pump  130  towards the distal/muzzle end of the AR-15 style firearm  101  can complete the reloading of a reserve magazine  210  such that it now becomes the active magazine  140 . For example, translating the pump  130  toward the distal end of the AR-15 style firearm  101  can reverse the motions of the levers  410 ,  411 ,  412 ,  413  back toward their initial position shown in  FIG. 7 . However, the reserve magazine  210  now located in the active magazine well  141  is now engaged with dowels  422  and  423  (and with corresponding dowels on the opposite side of the lower receiver  120 ). As can be seen by comparing  FIG. 9A  with  FIG. 7 , the movement of dowels  422  and  423  will be upward and forward toward the distal muzzle end of the AR-15 style firearm  101 . The reserve magazine  210  located in the active magazine well  141  can then be pushed upward in the active magazine well  141  by the dowels  422 ,  423  as they slide along the magazine adapter slots  216  while moving upward toward their starting positions (shown in  FIG. 7 ). 
     Just before the pump  130  is translated all the way forward (toward the muzzle end), dowel  423  finishes pushing the replacement magazine  210 / 140  upward such that it can engage the active magazine catch-and-release  144 , which holds it in place, as shown in  FIGS. 11A and 11B . The dowel  423  also slides completely out of the magazine adapter slot  216 , such that the levers  410 ,  411 ,  412 ,  413  have each returned to their respective starting position as shown in  FIG. 7  and are clear of the active magazine well  141 . 
     With a new reserve/active magazine  210 / 140  now locked place, the conventional bolt catch-and-release arrangement  114  on the lower receiver  120  can be activated, such that the bolt mechanism  113  in the upper receiver  110  will convey a cartridge from the new active magazine  210 / 140  and move it into a position for firing. This step may be unnecessary, e.g., if the reloading process was begun without first pulling back the bolt mechanism  113  on the upper receiver  110 . 
     In an alternative embodiment of the present disclosure, an AR-15 style firearm  101  or the like can be provided wherein any two or more of the upper receiver  110 , the lower receiver  120 , and the buttstock  102  may be permanently attached to each other. In still further embodiments, a magazine track  200 , pump  130  and lever arms  410 ,  411 ,  412 ,  413  (as well as other related components described herein) or their functional equivalents can be provided with other types of firearms (e.g., automatic or semi-automatic pistols or the like) to facilitate storage and automatic or semi-automatic reloading of one or more reserve magazines as described herein. 
     The exemplary embodiment of the disclosure illustrated in  FIG. 7  includes a magazine track  200  that is configured to store three reserve magazines  210 . In still further exemplary embodiments, an AR-15 style firearm  101  can be provided with a magazine track  200  that is configured to store one, two or more than three reserve magazines  210 . 
     The magazine track  200  and associated components may be composed of the same or different materials. Component materials that may be used in exemplary embodiments of the present disclosure include, but are not limited to, steel, titanium, aluminum, K-monel, composite materials, and engineering plastics. Alternative materials for certain components such as the follower  201 , pump tongue  802 , magazine adapter  212 , that may benefit from reduced friction include, but are not limited to, UHMW-PE, acetal polymers, NYLON 6, and Acrylonitrile Butadiene Styrene (“ABS”). Materials that may be suitable to form the pump  130  can include, but are not limited to, glass-filled nylon, ABS, other engineering plastics, steel, stainless steel, titanium, aluminum, metal alloys, and K-monel. 
     In further embodiments of the disclosure, certain components and mechanisms described herein may have structures or features that differ from the detailed embodiments described, while performing substantially the same functions. For example, the magazine track  200 , the reserve magazines  210 , and/or the magazine adapter  212  may have specific shapes that vary from the exemplary configurations described and illustrated herein, where such alternate shapes still facilitate motion of the reserve magazine  210  to move horizontally along the magazine track  200 . 
     As a further example, the embodiment shown in  FIG. 4A  includes a magazine track  200  with a magazine track groove  217  provided on each of its inner lateral sides configured to receive the edge protrusions  215  of the magazine adapter  212 , such that the reserve magazine  210  can be translated along the magazine track  200 . Alternative embodiments of the magazine track  200  may provide the magazine track  200  as a protrusion or rail that can be received by corresponding structures or features on the magazine adapter  212 , thereby also facilitating longitudinal movement of the magazine adapter  212  (and also the entire reserve magazine  210 ) along that rail. Grooves or recesses can also be provided on the magazine adapter  212  that are configured to engage the dowels  422  and  423  as described herein. 
     The features provided on the reserve magazine  210  that interact with the magazine track  200  may be provided as a separate magazine adapter  212 , as described herein, where such adapter can be affixed or coupled to a conventional magazine  211 . In further exemplary embodiments, the reserve magazine  210  can be provided as a custom or purposed component that is adapted for use with the magazine track  200  and other mechanisms as described herein. In a still further embodiment, the magazine adapter  212  may not surround a conventional magazine  211  as shown in  FIG. 3 , but it may instead be a component that can clip onto a conventional magazine  211  that includes just the edge protrusions  215  and a structure that contacts the active magazine well wall  142  to correctly position the reserve magazine  210  while it is moved upward into the active magazine well  141 . Alternatively, the magazine adapter  212  may include just the edge protrusions  215  attached to the conventional magazine  211 , where the shape and/or position of the active magazine well wall  142  can be configured to contact a portion of a conventional magazine  211  to correctly position it in the active magazine well  141 . 
     The embodiment for the reloading process described herein above includes an exemplary pump  130 , as shown in  FIG. 1 , that is configured to slide along a direction substantially parallel to the main axis of the lower receiver  120 , e.g., first moving proximally towards the direction of the buttstock  102  and then distally back towards the muzzle  111 , as described herein for the exemplary magazine reloading procedure. Alternative embodiments of the present disclosure may include, but are not limited to, protrusions or rails affixed to or formed as part of the lower receiver  120 , with corresponding recesses or grooves provided in the pump  130  that are configured to receive such rails. Bearings can optionally be provided for any of the sliding components described herein to reduce resistance of the sliding movement and/or improve stability of the mechanism. Alternatively or additionally, low-friction materials known in the art can be used to form or coat portions of the components that are in contact to again reduce resistance of the sliding movement. In a further embodiment, the recesses or grooves may be attached to (or formed as part of) the lower receiver  120 , and the rails attached to (or formed as part of) the pump  130 . Still further embodiments may include different shapes of the pump  130 , which may be selected based on aesthetics and/or functionality, e.g., to protect the stored reserve magazines  210 , provide a good grip to facilitate the pump sliding motion during magazine reloading, etc. 
     The design and action of the exemplary lever arms  410 ,  411 ,  412 ,  413  may be provided in different configurations that result in one or more lever arms with structures adapted to engage a reserve magazine  210  and move it upward into the active magazine well  141  until it is held in place by an active magazine catch-and-release  144 , similar to the procedure described herein and illustrated in  FIGS. 7-11 . Alternative embodiments of the mechanism for guiding a reserve magazine  210  from the magazine rack into the active magazine well  141  can include one or more lever arms having different lever arm shapes and/or sizes, different numbers of lever arms, different pivot points or pivot point designs, different configurations on each side of the magazine track  200 , providing one or more lever arms on only one side of the magazine track  200  (instead of symmetrically on both sides as described herein), and lifting the reserve magazine  210  into the active magazine well  141  from the bottom instead of or in addition to the magazine adapter slots  216  on the sides. Alternate embodiments of the reserve magazine release trigger  424  may provide such trigger on a lever arm other than the third lever arm  412  and configured to provide an equivalent action. 
     In an exemplary embodiment described above, the lever arms  410 ,  411 ,  412 ,  413  are actuated by a horizontal movement of the pump  130  along the axis of the firearm. Alternative embodiments for actuating the one or more lever arms may include, but are not limited to, a configuration of springs that can store energy created by a user motion and are subsequently released, or a component configured to be grasped and moved laterally with respect to the AR-15 style firearm  101 , which may then transfer the applied force to the one or more lever arms. For example, the component to be grasped and moved from the firearm may be provided as, e.g., a lever with a pivot on one end or a handle attached to a retractable cord or cable. 
     In further exemplary embodiments, a pin or mechanical catch can be provided to lock the pump  130  in place such that it is not susceptible to haphazard or accidental sliding movements when the AR-15 style firearm  101  is not being reloaded with a reserve magazine  210 . In another alternative embodiment, the pump  130  may be held in place by a mechanism that releases the pump  130  for sliding when sufficient force is applied, but prevents the pump  130  from moving in response to unintentional bumps or movement of the lower receiver  120 . 
     The magazine track  200 , lever arms  410 ,  411 ,  412 ,  413 , and reserve magazines  210  may optionally be encased by a protective covering in addition to being at least partially surrounded by the pump  130  or, e.g., where a pivoting lever is used instead of the pump  130 . Such covering can protect the components from exposure to dirt moisture, debris, or the like, which may facilitate smooth and reliable operation of the various components and mechanisms as described herein. 
     The buttstock  102  is shown in  FIG. 1  as a separate component at one end of the exemplary AR-15 style firearm  101  that can be attached to the lower receiver  120 . In alternative embodiments, the buttstock  102  may be formed as a part of the lower receiver  120 . 
     Alternative designs for the active magazine catch-and-release  144  and the part with the reserve magazine catch  502  and reserve magazine release lever  601  may also be used to accomplish the identical functions. The present embodiments are, therefore, to be considered as merely illustrative and not restrictive. In particular, a number of part shapes with the reserve magazine catch  502  and the reserve magazine release lever  601  may be designed to achieve the same function, including having multiple parts. The part with the reserve magazine catch  502  and reserve magazine release lever  601  may be on one side of the magazine track  200 , on both sides or in another position to achieve the same functionality. 
     Alternative embodiments of the magazine track  200  may be designed. For example, the magazine track  200  may be constructed such that reserve magazines  210  are stored into either or both sides of the magazine track  200 . Another embodiment may include specified slots within the magazine track  200  that correspond to the number of reserve magazines  210  the magazine track  200  is capable of storing. Alternatively, the magazines may be stored into the side of the magazine track  200 , which has no specific slots and is a continuous unbroken track. Another embodiment may include an entire side of the magazine track  200  flipping down, or opening up such that the magazine track  200  can accommodate a plurality of magazines by storing the reserve magazines  210  into specified magazine slots and then closing the opening in the magazine track  200 . 
     Further exemplary embodiments of the disclosure can include either permanent or interchangeable attachments provided within the magazine track  200  to which reserve magazines  210  may be attached or affixed such that the magazine track  200  need not be opened. For example, one or more magazine adapters  212  may be stored in the magazine track  200  as described herein, and then conventional magazines  211  or specially shaped ones may be inserted directly into the magazine adapters  212  from below to be stored. In this embodiment, the magazine adapters  212  and/or conventional magazines  211  can be configured such that the magazines  211  are reliably affixed to the stored magazine adapters  212  when inserted into them from below the magazine track  200 . 
     In another alternative embodiment, the lower receiver  120  can be provided as two pieces, an upper unit and a lower unit. The upper unit can include attachment points configured to affix the upper unit to the upper receiver  110 , the active magazine well  141 , trigger components  122 , pistol grip  121  and the attachment point for the buttstock  102  (or to the buttstock  102  itself). The lower unit can include the magazine track  200 , follower  201 , compression spring  202 , pump— 130 , and the various components mechanically coupled to the pump  130 . The upper and lower units may be rotatably coupled to each other by a pivot provided on their distal ends (e.g., the ends closest to the muzzle  111 ), and may be affixed to each other at their proximal ends (e.g. close to the active magazine well  141 ) by a catch or locking arrangement. To initially store reserve magazines in the firearm, the locking arrangement can be released to allow the proximal end of the lower unit to swing from the upper unit on the pivot, e.g., in a downward direction. The reserve magazines  210  may then be inserted into the magazine track  200  directly (instead of being slid in from the end of the magazine track  200  as described in other embodiments herein. The lower unit can then be pivoted upward back to its original position and locked to the upper unit, thereby securing the reserve magazines  210  in the magazine track  200 . This embodiment avoids a positioning of each reserve magazine  210  in the active magazine well  141  to then slide it into the magazine track  200 . 
     In yet another exemplary embodiment, a door or panel can be provided at the distal (muzzle) end of the magazine track  200 . For example, the pump wall  501  can be configured as a removable component. Opening the panel can expose the distal end of the magazine track  200  and allows the compression spring  202  and follower  201  to be removed through the opening. The distal (muzzle) end of the compression spring  202  may be a separate component, or it may optionally be affixed to the panel. One or more reserve magazines  210  may then be inserted into the magazine track  200  from the distal end. The reserve magazine catch  502  can hold the first reserve magazine  210  inserted onto the magazine track  200  to prevent it from exiting the proximal end of the track and into the active magazine well  141 . The follower  201  and compression spring  202  can then be reinserted into the magazine track  200 , with the compression spring  202  being compressed against the stored reserve magazines  210 , and the panel then closed or reattached to complete the storage procedure for the reserve magazines  210 . 
     In still another embodiment, a removable panel (e.g., the pump wall  501  or the like) can be provided at the distal end of the magazine track  200 , as described above. The follower  201  in the magazine track  200  can be moved into a fully retracted position within the magazine rack  200 , compressing the compression spring  202 , e.g., by manipulating a follower lever coupled to the follower  201 . The follower lever can then be twisted or shifted to lock the compression spring  202  and follower  201  in place in the fully compressed position with a spring catch-and-release arrangement. The follower lever, compression spring  202  and follower  201  can optionally be affixed to the removable panel, and these components can be removed together to expose the distal end of the magazine track  200 . One or more reserve magazines  210  can then be inserted into the magazine track  200  from the distal end, and held in the magazine track  200  by the reserve magazine catch  502 . The panel with compression spring  202  and follower  201  can then be replaced at the distal end of the magazine track  200 , and the compression spring  202  may then be released from the locked position so that the compression spring expands and the follower  201  exerts a force on the reserve magazines  210  towards the active magazine well  141 . 
     In another embodiment of the disclosure, an exemplary firearm  1200  (shown in  FIG. 12 ) can be provided that facilitates storage and semi-automatic or powered reloading of reserve magazines  210 . The firearm  1200  can be provided with a magazine track  200  configured to store one or more reserve magazines  210 , similar to the exemplary AR-15 style firearm  101  shown in  FIGS. 1 and 2A-2B . Certain components of the exemplary firearm  1200  that are not explicitly shown or labeled in  FIGS. 12-15  can generally correspond to similar features provided in the exemplary AR-15 style firearm  101  and illustrated in the preceding figures. 
     In operation, an active magazine  140  can be manually inserted into the active magazine well  141  and locked into place by the active magazine catch-and-release  144  (not labeled in  FIG. 12 ), as described herein with respect to the AR-15 style firearm  101 . This is similar to a magazine loading process for certain conventional firearms. When the active magazine  140  is exhausted of cartridges or replacement with a full magazine is desired, the active magazine release button  143  (not shown in  FIG. 12 ) can be depressed or activated to release the active magazine catch-and-release  144  allowing the active magazine  140  to be manually pulled out of the active magazine well  141  or drop out of it due to gravity. A magazine reloading button (not shown), which may be located at any convenient location on the firearm  1200  (e.g., near the trigger, on the pistol grip  121 , on the lower receiver  120 , etc.) can then be activated to actuate an automated or powered mechanism that is adapted to move a reserve magazine  210  from storage inside the magazine track  200  to a locked position in the active magazine well  141 . 
     In one exemplary embodiment of the disclosure, a constant torque spring  1203  that includes two drums, as shown in  FIG. 12 , can be provided on the distal (muzzle) side of the magazine track end wall  1205 . Such constant torque spring  1203  can be configured to provide a force to actuate certain mechanisms for reloading of a reserve magazine  210  into the active magazine well  141  of the firearm. The smaller drum  1204  of the constant torque spring  1203  can be affixed to a distal end of a primary drive shaft  1202  that passes through an opening in the magazine track end wall  1205  and extends in a direction substantially parallel to the main axis (e.g., the barrel axis) of the firearm  1200 , such that the smaller drum  1204  and primary drive shaft  1202  rotate together. The proximal portion of the primary drive shaft  1202  (e.g., the end closer to the trigger and buttstock  102 ) passes through a drive shaft connection structure  1217  proximal to the active magazine well  141 . The proximal end of the primary drive shaft  1202  can be coupled to a drive shaft force transmission lever  1209 . The primary drive shaft  1202  is largely obscured in  FIG. 12  because much of its length is surrounded by a helical gear  1211 . A primary transmission gear  1201  can also be affixed to the primary drive shaft  1202  such that it can transfer a rotational force from the constant torque spring  1203  to one or more coupled secondary transmission gears  1206 . For example, the exemplary configuration illustrated in  FIG. 12  includes three secondary transmission gears  1206 . One of the secondary transmission gears  1206  can be affixed to the secondary drive shaft  1208  such that they rotate together. This exemplary configuration facilitates a transfer of rotational forces from the constant torque spring  1203  to the primary drive shaft  1202  and the primary transmission gear  1201  affixed thereto, and from the primary transmission gear  1201  to the one or more secondary transmission gears  1206 , and from one secondary transmission gear  1206  to the secondary drive shaft  1208 . 
     The secondary drive shaft  1208  passes through an opening provided in the magazine track end wall  1205  and extends in a direction substantially parallel to the main axis of the firearm  1200 , with the proximal portion of the secondary drive shaft  1208  also passing through the drive shaft connection structure  1217  and connecting to a further drive shaft force transmission lever  1209 , similar to the primary drive shaft  1202 . A helical gear  1211  can be provided around at least a portion of the primary drive shaft  1202  and attached to it such that they rotate together, as shown in  FIG. 12 . A charging handle  1207  that engages with the groove of the helical gear  1211  is configured such that when the charging handle  1207  is pushed in one direction, e.g., towards the distal (muzzle) end, it exerts a rotational force on the helical gear  1211  which rotates the primary drive shaft  1202 , thereby turning the smaller drum  1204  of the constant torque spring  1203  to wind it up, increasing tension in the constant torque spring  1203 . The charging handle  1207  can be constrained to travel along the length of the helical gear  1211  but not rotate around it, such that the charging handle  1207  is directed outward from the helical gear  1211  in a substantially constant direction as it moves longitudinally. As the constant torque spring  1203  is allowed to relax, the primary drive shaft  1202  rotates in the opposite direction, thereby rotating the helical gear  1211  and moving the charging handle  1207  back to its original position. In further embodiments, the charging handle  1207  can be configured to travel in the opposite direction, e.g., it can be pulled toward the buttstock end of the firearm  1200  to wind up the constant torque spring  1203 , and then return back towards the distal/muzzle end when released in response to the unwinding or relaxing constant torque spring  1203 . 
       FIG. 13  is a view along the inside of the magazine track  200  of the firearm  1200  looking towards the proximal (buttstock) end. A magazine lift mechanism  1213  can be provided that is configured to move a reserve magazine  210  from underneath the active magazine well  141  up into the active magazine well  141  until it engages the active magazine catch-and-release  144 , thereby securing the reserve magazine  210  in the active magazine well  141  to facilitate transfer of cartridges from the reserve magazine  210  into a firing chamber (not shown) to be fired by the firearm  1200 . The exemplary magazine lift mechanism  1213  illustrated in  FIGS. 12 and 13  can be constrained to move in a substantially vertical direction, e.g., along corresponding active magazine well wall track grooves  1216  provided in the active magazine well wall  1215 . The magazine lift mechanism  1213  can be moved up and down by the drive shaft force transmission levers  1209 . For example, the drive shaft force transmission levers  1209  can be provided with pins or the like that engage with a substantially horizontal slot provided in the magazine lift mechanism  1213 , as shown in  FIG. 12 . As the drive shaft force transmission levers  1209  rotate (e.g., together with the primary and secondary drive shafts  1202 ,  1208  to which they are affixed), the pin on each drive shaft force transmission lever  1209  can rotate around the axis of the corresponding drive shaft  1202 ,  1208  while engaging the magazine lift mechanism  1213  through the slot therein, thereby lifting or lowering the magazine lift mechanism  1213 , depending on the direction and amount of rotation. 
     The exemplary magazine lift mechanism  1213  as illustrated in  FIG. 13  includes two lift protrusions  1304  that project into the central region of the magazine track  200  near the active magazine well  141 . These lift protrusions  1304  may be configured to engage the magazine adapter slots  216  of a reserve magazine adapter  212  (shown in  FIG. 3 ) on both sides when the magazine lift mechanism  1213  is in a downward position, e.g., lowered from the active magazine well  141 . After the reserve magazine  210  with the magazine adapter  212  is released and pushed from the magazine track  200  toward the active magazine well  141  (e.g., in a manner similar to that described herein for the exemplary firearm shown in  FIGS. 1, 7, 9A, 9B, and 10A -D), it may then slide onto the lift protrusions  1304  which position the reserve magazine  210  beneath the active magazine well  141  (not shown in  FIG. 13 ). 
     As shown in  FIG. 14 , the magazine lift mechanism  1213  may then be pushed upward toward the active magazine well  141  (by the rotation of the drive shaft force transmission levers  1209 ) such that the reserve magazine  210  will engage the active magazine catch-and-release  144 . (Reserve magazine  210  is not shown in  FIG. 14 ) The upper portions of the active magazine well wall track grooves  1216  provided in the active magazine well wall  1215  can diverge outward (e.g. away from the central axis of the firearm  1200 ), as shown in  FIGS. 12 and 13  such that the lift protrusions  1304  will move sideways and retract outwardly when the magazine lift mechanism  1213  is raised high enough in the active magazine well wall track grooves  1216 . In this manner, the lift protrusions  1304  can disengage from the magazine adapter  212  after the reserve magazine  210  has been inserted into the active magazine well  141 , engaged by the active magazine catch-and-release  144 , and is ready to dispense cartridges into the firing chamber. 
     As shown in  FIG. 15 , the drive shaft force transmission levers  1209  may be coupled to the drive shafts  1202  and  1208  via clutch arrangements, for example ball bearing clutches  1507  or the like. The clutch arrangements  1507  can be directional, for example, such that they prevent the drive shaft force transmission levers  1209  from rotating when the drive shafts  1202 ,  1208  rotate in the direction that charges or winds the constant torque spring  1203 , e.g., during the initial movement direction of the charging handle  1207 . This configuration can restrict the drive shaft force transmission levers  1209  to rotate only when the constant torque spring  1203  is releasing energy, e.g., when the charging handle is released. This rotation can result in the pins at the end of the drive shaft force transmission levers  1209  turning in a full circle around a horizontal axis as they slide along the slots provided in the magazine lift mechanism  1213 , thereby translating the rotation of the drive shafts into a vertical movement that may be transferred to the magazine lift mechanism  1213 . 
     One or more reserve magazines  210  can be stored in the magazine track  200  of the firearm  1200  in a manner similar to that described herein with respect to the exemplary AR-15 style firearm  101 . For example, the firearm  1200  can also include a compression spring  202 , a follower  201 , and a reserve magazine catch  502  that can hold the reserve magazines  210  in the magazine track  200 . Energy can be stored in the constant torque spring  1203  by moving the charging handle  1207  in a first direction, as described above. To reload a reserve magazine  210  that may contain additional cartridges to fire, the active magazine catch-and-release  144  can be activated (e.g., by pressing a button or moving a mechanical switch) to empty the active magazine well  141 . The reloading of a reserve magazine  210  into the now-empty active magazine well  141  can then be performed as follows. 
     A first locking mechanism (not shown) holding the magazine lift mechanism  1213  in a raised position can be released, allowing the magazine lift mechanism  1213  to lower under the force provided by the constant torque spring  1203  via the drive shafts  1202 ,  1208  and drive shaft force transmission levers  1209  as described herein. When the magazine lift mechanism  1213  reaches a lowermost position, it may be held in place by a second locking mechanism (not shown). A mechanical coupling between the magazine lift mechanism  1213  and the reserve magazine catch  502  can release the reserve magazine catch  502  (e.g., as described with respect to the AR-15 style firearm  101  herein), thereby releasing a reserve magazine  210  that is then pushed under the active magazine well  141  by the compression spring  202  and follower  201 , at which point it is held by the lift protrusions  1304 . 
     When the magazine adapter  212  on the reserve magazine  210  is pushed against the active magazine well wall  1215 , it can be configured to release the second locking mechanism (not shown). This allows the magazine lift mechanism  1213  to rise based on the spring-driven rotation of the drive shaft force transmission levers  1209 , which raises the reserve magazine  210  into the active magazine well  141  where it can be secured in place by the active magazine catch-and-release  144  before the lift protrusions  1304  retract and release their hold on the magazine adapter  212 . This reserve magazine  210  is now the active magazine  140 , and it is in position to dispense cartridges into the firing chamber of the firearm  1200 . 
     The exemplary firearm  1200  may include alternate configurations and/or specific components that may perform substantially the same actions. For example, the constant torque spring  1203  that rotates the drive shafts  1202 ,  1208  may be replaced with different types of energy storage devices, e.g., an electric motor (with associated power source), a pre-loaded spring arrangement that can retain sufficient potential energy to reload all reserve magazines  210  stored in the magazine track  200 , or the like. Similarly, alternate components or configurations may be used to wind or otherwise store energy in the constant torque spring  1203  or motor instead of the exemplary helical gear  1211  and charging handle  1207  described herein. 
     In a further embodiment, the firearm  1200  may be configured such that the entire magazine reloading procedure may be automated and activated by a single button or lever. For example, conventional levers, catches, ratcheting mechanisms, or the like that are known in the mechanical arts can be used such that sequential motion of the various components described herein can mechanically initiate subsequent processes, including the various locking or releasing steps. 
     Still further embodiments of the present disclosure may include additional features, gadgets and/or accessories or different configurations of the magazine track  200 . For example, the AR-15 style firearm  101 ,  1200  may be provided with a plurality of magazine tracks  200 . Individual reserve magazine  210  may be joined to other accessories such as conventional coupled magazines, or other weapons or equipment. 
     In yet another exemplary embodiment, a circular magazine track  200  can be provided that can retain spent magazines in the magazine track  200 . Such circular magazines that cannot leave the magazine track may be capable of being reloaded while still connected to the magazine track  200 . The circular magazine track may be constructed to store fixed magazines. 
     The foregoing merely illustrates the principles of the present invention. Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention from a study of the drawings, the disclosure, and the appended claims. In the claims, the word “comprising” does not exclude other elements or steps and the indefinite article “a” or “an” does not exclude a plurality. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used advantageously. Any reference signs in the claims should not be construed as limiting the scope of the claims. Various modifications and alterations to the described embodiments will be apparent to those skilled in the art in view of the teachings herein. It will thus be appreciated that those skilled in the art will be able to devise numerous techniques which, although not explicitly described herein, embody the principles of the present invention and are thus within the spirit and scope of the present invention. All references cited herein are incorporated herein by reference in their entireties.