Abstract:
An advanced reloading mechanism for an automatic or semi-automatic weapon includes a firing chamber, a firing bolt and an ammunition magazine-well configured to receive an ammunition magazine with an outer casing. The outer casing of the magazine has a cavity and a spring driven follower in said cavity. An automatic magazine release mechanism is cooperated with an actuator of a first ammunition magazine, so that the first ammunition magazine is automatically released and expelled from the magazine well when the actuator reaches a predetermined position with respect to said magazine well. Further; a bolt catch mechanism is included to hold the firing bolt and chamber in an open position when a last bullet of the first ammunition magazine is fired. The bolt catch mechanism includes an extension pivotably attached to the weapon, being spring-loaded and extending into the magazine well of said weapon to operably cause said bolt catch mechanism to release said bolt and close said chamber when a second ammunition magazine is fully inserted into the ammunition magazine well.

Description:
RELATED APPLICATIONS 
       [0001]    The present patent application claims priority as a continuation-in-part application to parent U.S. patent application Ser. No. 14/725,051, filed on May 29, 2015, the description and drawings of which are incorporated herein in the entirety. 
     
    
     FIELD OF INVENTION 
       [0002]    The present invention is generally related to ammunition magazines and related weapon parts for automatic and semi-automatic weapons. In particular, the present invention is directed to a modification in ammunition magazines and weapons to facilitate automatic ejection of an empty ammunition magazine and expedited reloading for firing rounds from a subsequent, loaded ammunition magazine. 
       BACKGROUND ART 
       [0003]    The purpose of modern automatic weapons, whether used in semi-automatic or full automatic modes, is to provide fast, accurate placement of rounds downrange at a desired target or targets. Speed and precision are the objectives when using such arms as the M4 (described in an operations manual cited in an attached Information Disclosure Statement) or one of its many variations and embodiments. A number of these embodiments are listed in the subject cited operations manual. However, there are many types of magazine-fed weapons with similar characteristics, and the discussion of conventional art is not limited to the M4 family. 
         [0004]    The major difficulty hindering the rapid fire of such weapons on a designated downrange target is the reloading cycle. The pauses or “downtime” occurring during the reloading cycle not only hinders the effective application of fire on a given target but also exposes the weapon operator to increased danger. Moreover, operators cannot easily protect themselves during those pauses. It is common for the weapon operator to lose sight of the target during the reloading cycle. If the weapon operator is engaged in competitive target shooting, the extra steps and the time expended for the reloading operations may put the weapon is operator at a competitive disadvantage. 
         [0005]    There have been many techniques for dealing with this drawback. These solutions have included larger magazines (such as large “banana” magazines) and physically connecting magazines together so that it is easier to lay hands on the new magazine once the old one is expended. In other cases, infantry tactics mandate staggered firing and reloading cycles, so that teamed weapon operators might protect themselves and each other more effectively during the pauses caused by the reloading cycle. While some of these techniques have been moderately effective, they are in general complicated, and do not substantially decrease time lost during the reloading cycle. In particular, none of these techniques encompass the automatic ejection of the spent magazine and automatic weapon preparation to chamber a round from a new magazine, for a weapon such as the M4 (and its many variations and derivations from the original AR15/M16). 
         [0006]    When using an automatic or semi-automatic weapon (such as an M4 or one s of its many variations, for example), it is conventionally necessary for the final round to be fired, and for the weapon operator to press a release button with one hand while pulling the spent ammunition magazine out with the other. Then, the weapon operator must drop the spent ammunition magazine, grab a new (i.e., loaded) ammunition magazine and slide it into the magazine-well or magazine-receiver of the weapon. The operator would then have to take the added step of pulling back on the bolt to put a new round in the firing chamber or, in the case of most automatic weapons, press a bolt release to automatically load the next round, before firing again. 
         [0007]    Further, the ejection of an ammunition magazine (even if it can be performed automatically as described in Applicant&#39;s parent application), leads to certain difficulties which slow the reloading process. In particular with the M4, as soon as the empty magazine is automatically ejected from the weapon magazine-well, the bolt normally closes. This means that it is necessary to manually operate the bolt once a new (i.e., loaded) magazine is inserted to chamber the first round of the reloading ammunition magazine. The result is that the weapon operator is required to use one hand to operate the bolt and the other hand to operate the bolt catch release. As a result, the weapon operator&#39;s eyes are often taken away from the target, and the operator must move at least one hand away from the firing position. This complicates and lengthens the reloading cycle, often leading to error and/or undesirable results. 
         [0008]    Automatic ejection of a spent ammunition magazine (as described in Applicant&#39;s parent application) helps to shorten the reloading cycle by reducing the necessary manual steps for the reloading process. However, this is not completely sufficient to provide a smooth, virtually automatic arrangement where an operator need only grab a new ammunition magazine and push it home into the weapon ammunition magazine-well. Rather, additional steps are still required in the reloading cycle. These steps create undesirable results in competition shooting and can lead to disastrous results in law enforcement and combat situations. 
         [0009]    Under the pressures of combat and/or law enforcement use, “anything that can go wrong will go wrong” applies to reloading cycles. Accordingly, it is extremely important to make each cycle as short and efficient as possible, by reducing the number of physical steps and movements that the operator of the weapon must perform to effect the reloading process. This is extremely important for the security of the weapon operator. Also, while competitive rapid-fire shooting does not entail the stresses of combat, the desire for rapid, accurate fire is still present. Because of this, competitive shooters prefer to limit the number of operations needed for reloading to limit the time that the weapon is off target. 
         [0010]    Accordingly, a fast and efficient simplification of the reloading cycle is needed to reduce the number of steps that the weapon operator must take during the reloading process and ultimately reduce the time necessary for the process. Moreover, automation of this process will benefit the weapon operator, especially if in combat or tense law enforcement situations and/or time-sensitive shooting completion. 
       SUMMARY OF THE INVENTION 
       [0011]    It is a principal goal of the present invention to facilitate the rapid and efficient reloading operation of an automatic or semi-automatic rifle, such as an M4 or one of its many variations. Therefore, the present invention reduces the number of physical operations or steps that a weapons operator must carry out when undergoing the reloading operation. 
         [0012]    It is another object of the present invention to make minimal physical changes to an existing weapon to accommodate the present invention. 
         [0013]    It is a further object of the present invention to facilitate the operation of the present invention with minimum alterations to standard weapons ammunition magazines. 
         [0014]    It is still another object of the present invention to provide an automatic release for the ammunition magazine once the last round from the ammunition magazine enters the weapon&#39;s firing chamber. Moreover, the present invention is includes an ammunition magazine release system that provides for easy, automatic removal of the ammunition magazine from the weapon. 
         [0015]    It is again an additional object of the present invention to provide an automatic ammunition magazine release system that can be accommodated, for example, by including modifications to an otherwise standard ammunition magazine follower. The present invention may also include an innovative modification to an otherwise standard ammunition magazine housing. 
         [0016]    It is still another object of the present invention to provide an automatic ammunition magazine release system that can be adapted to a wide range of magazine-fed automatic and semi-automatic weapons. 
         [0017]    It is yet a further object of the present invention to provide a system for removing ammunition magazines, by requiring fewer steps and movements of the weapon operator. 
         [0018]    It is again another object of the present invention to provide an ammunition magazine release system that automatically controls the weapon bolt, so that the weapon operator may avoid manually operating the weapon bolt during the reloading cycle. 
         [0019]    It is yet another object of the present invention to provide an ammunition magazine release system that automatically chambers the first round when a newly reloaded ammunition magazine is placed in the ammunition magazine-well of a weapon. 
         [0020]    It is again a further object of the present invention to provide a system for reloading in which the weapon operator is required to use only one hand in the process. 
         [0021]    It is still an additional object of the present invention to provide an ammunition magazine release system that allows the weapon operator to more easily keep sight on the target, without complication, interruption and/or distraction. 
         [0022]    These and other goals and objects of the present invention are achieved by an automatic bolt control system for an ammunition magazine-fed automatic or semi-automatic weapon. In a typical situation, the weapon has an ammunition magazine-well and a manual bolt catch mechanism configured to hold and release the weapon bolt. Moreover, the control system in this case includes a spring position to hold the bolt catch mechanism in an open position when a last bullet of a first ammunition magazine is fired and a corresponding empty shell is automatically ejected from the weapon. Included is an extension of the bolt catch mechanism pivotally attached to the weapon, spring loaded, and extending into the magazine-well. In operation, the extension is used to automatically close the bolt when a second (i.e., reloaded) ammunition magazine is fully inserted into the magazine-well of the weapon. 
         [0023]    Another embodiment of the present invention includes a method for controlling the bolt of the automatic or semi-automatic weapon when replacing a first (i.e., spent) ammunition magazine from an ammunition magazine-well on the weapon. The process includes the step of automatically holding the bolt catch mechanism open by a catch mechanism being pivotally attached and spring-loaded to the weapon such that an arm of the catch mechanism extends into the magazine-well thereby catching and holding the bolt in an open position when a last bullet of the first ammunition magazine is fired and the corresponding shell automatically ejected from the weapon. The subsequent step includes closing the bolt catch mechanism when inserting a second (i.e., loaded) ammunition magazine into the ammunition magazine-well of the weapon, by contacting the arm extending into the magazine-well to pivot the catch mechanism, thereby releasing the bolt. 
         [0024]    A further embodiment of the present invention is to provide an expedited reloading sequence for an automatic or semi-automatic weapon that is fast and easy, such that the firing chamber, in direct communication with a magazine-well, automatically receives a round from an external ammunition magazine when placed in the magazine-well. Specifically, the ammunition magazine in this case includes an outer casing having at least one aperture and a spring driven follower with a spring driven perpendicular prong or plunger extending through said aperture. The weapon further includes a magazine catch configured to hold an external ammunition magazine in the magazine-well and a bolt catch mechanism operable to hold the firing chamber open when an empty (i.e., spent) external magazine is removed from the magazine-well. In operation, the sequence typically includes moving rounds in the first ammunition magazine upwards through the magazine by means of a spring driven follower. When the last round of the magazine is placed in the firing chamber, the empty magazine is automatically is released from the magazine-well via the engagement prong or plunger. Then, when the last round is expended, the firing chamber is automatically held open. Subsequently, a new (i.e., loaded) ammunition magazine is placed in the magazine-well and the firing chamber automatically closes on a first round in a new magazine and the operator remains in a position to continue firing. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0025]    The drawings included herewith are for the purpose of illustration only and not as a definition of the limits of the instant invention, for which reference should be made to the claims appended hereto. Other features, objects and advantages of this invention will become clear from the following more detailed description made with reference to the drawings in which: 
           [0026]      FIG. 1  is a left, side view of the type of conventional automatic or semi-automatic weapon (M4) in which the present invention can operate. 
           [0027]      FIG. 2  is an exploded view of a portion of the weapon depicted in  Figure 1 , identifying those parts of the conventional weapon that interact with both the present invention and that of the invention described in the parent application. 
           [0028]      FIG. 3A  is a perspective view of a conventional outer casing of an ammunition magazine. 
           [0029]      FIG. 3B  is a perspective depiction of the interior parts of the conventional is ammunition magazine of  FIG. 3A . 
           [0030]      FIG. 4  is a perspective view of a conventional loaded ammunition magazine, depicting multiple rounds contained within the casing, and a mechanism on the outer casing for interfacing with the weapon of  FIG. 1  for holding the magazine in the magazine-well of the weapon. 
           [0031]      FIG. 5  is a partial side view of the weapon of  FIG. 1 , depicting a line for a cutaway for a sectional view for  FIG. 6  to show the improvement described in this instant application which works with the otherwise conventional mechanism used for holding the magazine in the magazine-well of the weapon depicted by line  7 A (for cutaway  FIG. 7A ) and line  8 A (for cutaway  FIG. 8A ) to show an arrangement by which the weapon bolt can be interactively triggered or moved in response to a new loaded ammunition magazine being placed into the magazine-well. 
           [0032]      FIG. 6  is a sectional view taken along line- 6  depicted in  FIG. 5 , illustrating a partially full ammunition magazine held in operating position within a magazine-well of the weapon, and depicting the position and spacial relationship of an inventive prong or plunger used to release the magazine by subsequent contact with the magazine catch or holding extension. 
           [0033]      FIG. 7A  is a top sectional view along line- 7 A shown in  FIG. 5 , depicting the same partially full ammunition magazine caught in the magazine-well by a holding extension. 
           [0034]      FIG. 7B  is an enlarged view of  FIG. 7A , better depicting the relationship between the magazine catch mechanism and the holding extension. 
           [0035]      FIG. 8A  is the top sectional view along line- 8 A shown in  FIG. 5  (just above line- 7 A) with the structure of the present invention, including the interacting and spacial relationship between a modified bolt catch mechanism and the partially full ammunition magazine shown in  FIG. 6 . 
           [0036]      FIG. 8B  is an enlarged view of  FIG. 8A  to better depict the relationship and alignment between the modified bolt catch mechanism and the ammunition magazine. 
           [0037]      FIG. 9A  is an enlarged perspective view of a conventional bolt catch mechanism. 
           [0038]      FIG. 9B  is another enlarged perspective view of the conventional bolt catch mechanism shown in  FIG. 9A  viewed from a slightly rotated direction to that of  FIG. 9A . 
           [0039]      FIG. 10A  is an enlarged perspective view of the bolt catch mechanism modified in accordance with the instant invention to include an extension arm. 
           [0040]      FIG. 10B  is an enlarged perspective view of the modified bolt catch mechanism viewed from a slightly rotated direction to that of  FIG. 10A . 
           [0041]      FIG. 11  is an exploded perspective view of the conventional bolt catch of  FIGS. 9A and 9B , depicting its pivotal mount location on the casing of the weapon and showing a spring biased from below the pivot point. 
           [0042]      FIG. 12  is an exploded perspective view of the modified bolt catch mechanism of  FIGS. 10A and 10B , depicting its pivotal mount location on the is casing of the weapon and showing a relatively stronger spring biased from above the pivotal point (i.e., opposite the spring biasing of the conventional bolt catch shown in  FIG. 11 ). 
           [0043]      FIG. 13  is a partially cut away view of a fully assembled weapon of  FIG. 12 , depicting the special relationship between the bolt catch mechanism and an ammunition magazine in the process of being inserted into the magazine-well. 
           [0044]      FIG. 14  illustrates the same perspective view as  FIG. 13 , but altered by the ammunition magazine being in a full engaged position within the weapon, thereby pivoting the catch mechanism (via contact between a detent of the newly loaded ammunition magazine and the extension arm of  FIG. 10A ) to release the bolt from the catch mechanism and close the firing chamber on a first round of the new magazine. 
           [0045]      FIG. 15A  is a perspective view of an ammunition magazine containing rounds, and modified in accordance with the present invention (including the invention of the parent application) for use as a single system for rapid reloading. 
           [0046]      FIG. 15B  illustrates the same ammunition magazine as  FIG. 15A  but with all the rounds expended. 
           [0047]      FIG. 16  is an enlarged sectional view identified within line- 16  depicted in  FIG. 6 , showing the internal mechanism and relationship between the modified magazine follower moving rounds into the firing chamber, the magazine release described in the parent application, and the inventive bolt catch mechanism of the instant application. 
           [0048]      FIG. 17A  is a sectional view taken in  FIG. 5  along the lines- 17 A (similar to  FIG. 6 ), but with this view depicting a last round of the ammunition magazine being moved to the firing chamber which, in turn, puts in motion the magazine release mechanism to engage the magazine holding extension so that the magazine automatically falls from the magazine-well, thereby putting in motion the bolt catch mechanism to prevent closure of the firing chamber upon firing the last round of the expended magazine. 
           [0049]      FIG. 17B  is an enlarged portion of  FIG. 17A  identified within line- 17 B, depicting details of the relationship between the ammunition magazine, the magazine release mechanism, and the bolt catch mechanism of the instant invention. 
           [0050]      FIG. 17C  is a depiction of  FIG. 17B , but in which the ammunition magazine (released from the weapon magazine-well) has moved downwards, thereby activating the inventive bolt catch mechanism to hold the weapon bolt and firing chamber open upon firing the last round of the now expended magazine. 
           [0051]      FIG. 18  is a perspective view of the ammunition magazine follower configured in accordance with the invention of the parent application for use in connection with the present invention. 
           [0052]      FIG. 19  is an exploded view of the inventive ammunition magazine follower shown in  FIG. 18 . 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0053]    The present invention is directed to automatic and semi-automatic weapons such as the M4, and its many variations, dating from the AR15/M16 to the present embodiments. More specifically, the present invention is directed to modifications of ammunition magazines and weapon parts that interface with the magazines for such weapons. Submitted as conventional art for this application is the instruction manual for the Bushmaster family of weapons. For illustrative purposes, parts of the Bushmaster manual dated 2005 have been incorporated into drawings of the present application as background for the application to better describe the invention with such firearms, although the instant invention may be used with other automatic and semi-automatic weapons. 
         [0054]    The invention of the present application is related to that of the parent application, although a separately operative, inventive development. Moreover, the invention of the present application addresses a condition resulting from the invention of the parent application. Accordingly, for purposes of clarity, parts of the parent application will be discussed and summarized below. 
         [0055]    In both the parent and the instant applications, the inventions are directed to interactive systems between a weapon and ammunition magazines. The ammunition magazine is modified from a standard conventional ammunition magazine. While the modifications to the ammunition magazine depicted in the drawings have been made to specifically fit the M4 family of weapons, other magazine-fed weapons (including both semi-automatic and automatic) can be adapted by incorporating the same modifications to the weapons and ammunition magazines as would be obvious to a person skilled in the art knowledgeable of the instant disclosures. This is true for the inventions of both the parent and the present application. 
         [0056]    For a weapon to benefit from the inventions of both applications, that weapon should have a standard manual ammunition magazine release mechanism and a bolt catch mechanism. In the preferred embodiment, alterations in the ammunition magazines can be made to correspond to the exact location of the magazine catch and release mechanism on the particular weapon. The M4 Bushmaster, as depicted in the cited instruction manual, is used as a representative weapon with both the inventions of the present application and the parent application because of the adaptability of both inventions to this particular weapon. However, either of the two inventions can be adapted to other automatic/semi-automatic weapons having appropriate ammunition magazine catch and bolt catch configurations. 
         [0057]    For clarity, in both the present and the parent applications, only those parts of the weapon that interact as part of a particular invention are designated in certain drawings. The other parts of the weapon are depicted in the drawings, but are not designated with numerals since they do not interact as part of a particular inventive system. For example, in conventional art  FIG. 1 , illustrative weapon  100  has only a limited number of parts designated with numerals. These are the parts most closely associated with the inventive alterations and/or additions. 
         [0058]    Conventional art  FIG. 2  is an exploded perspective view of a portion of a weapon lock that is most relevant to the present invention. The parts depicted therein are found in a conventional M4 rifle. Those parts that relate to the inventive interactive system of the parent application include magazine release button  101  and magazine catch spring  102 . Magazine release catch  104  is connected to the magazine release button  101  through an aperture  121  in the weapon casing or housing  120 . The magazine catch  104  includes a holding extension  105  which interfaces with the external magazine  10  (shown in  FIG. 4 ). It is noted that the invention of the parent eliminates the need to manually operate magazine release button  101 . 
         [0059]    Also identified in conventional art  FIG. 2  are the parts of the bolt catch mechanism  160 , which are associated with the new invention presented in the instant application. Bolt catch mechanism  160  includes an operating button  161 , a plunger  162 , a plunger spring  163 , and an internal bolt catch engagement interface  164 . It is noted that the spring and plunger bring the operating button  161  back to its normal position after it has been depressed to operate the weapon bolt  108 , using mechanisms configured to interact with the bolt controls internal to casing/housing  120 , in a conventional manner. A detailed depiction of the bolt catch mechanism  160  is shown in  FIGS. 9A and 9B . Operation of the standard bolt catch mechanism  160  in the M4 rifle is already documented and well-known. Consequently, no further discussion is necessary to appreciate the conventional operation of this mechanism. 
         [0060]    In normal operation, the weapon operator must manually press magazine release button  101  to operate the magazine catch  104  and thus the holding extension  105  that holds the magazine to the weapon. Once the magazine release button is pressed, it is possible to pull ammunition magazine  10  from the magazine-well  110 . This conventional operation requires extra movement on the part of the weapon operator, and as a result, the weapon is not easily held on target. Further, an often unacceptable amount of time is needed before the weapon can be put back in use and on target, due to the fact that both of the weapon operator&#39;s hands are needed to carry out the removal of the spent ammunition magazine  10 . 
         [0061]    In addition, a weapon operator must move his hand to operate bolt catch mechanism  160 . This is necessary in order to close the bolt  108  when the normal operation of the weapon leaves the bolt open. However it should be understood that the release of an ammunition magazine  10  from the magazine-well  110  will cause the bolt  108  to normally close in an M4. To open the bolt to receive a new round from a new (i.e., loaded) ammunition magazine, the operator must manually pull the bolt  108  back once a new ammunition magazine is inserted into magazine-well  110 . This creates substantial difficulty for the weapon operator who wants to continue to fire rapidly downrange without major pause and disruption. The key to addressing both of these time-consuming tasks lies in part with the ammunition magazine  10 . 
         [0062]    A conventional ammunition magazine is depicted in  FIGS. 3A, 3B and 4 . The magazine  10  illustrated in these Figures is adapted specifically for the M4 weapon. Accordingly, the inventive modifications for the interactive system in this case are depicted for this particular type of ammunition magazine, but the same design and concept can be applied to other weapon types with similarly configured magazines using modest changes and equivalencies. Moreover, the conventional ammunition magazine of  FIGS. 3A, 3B and 4  includes a casing  11  and a follower  14 . A base plate  12  is provided to support a spring  13  which drives follower  14 . At the top of follower  14  is an upper support  15  to hold rounds, and a spacer  151  so that a double row of off-set rounds can be placed in the magazine  10 . This is best seen in  FIG. 4 , where the double row of rounds  300  is vertically off-set from each other. This off-set configuration is shown more clearly with description of the instant invention in  FIGS. 6 and 16 . Upper curl  111  of casing  11  keeps the rounds  300  in place and positioned to enter the firing chamber  107  of the weapon  100 . 
         [0063]    The conventional casing  11  of ammunition magazine  10  also includes an aperture  16  and a catch lip  17 . Both of these structures are sized and located to interact with holding extension  105  of magazine catch  104 . This is the structure that conventionally holds the magazine within the magazine-well  110  of weapon  100 . When the operator pushes the magazine release button  101 , the entire magazine catch is moved outward away from the magazine-well  110  (i.e., the magazine holding extension  105  is pushed away from catch lip  17  on the magazine). This action allows the operator to then pull out the magazine  10  from the magazine-well  110 . 
         [0064]    Regarding the instant invention,  FIG. 5  illustrates an enlarged left side view of weapon  100 . The purpose of this figure is to best illustrate the preferred embodiment of the instant invention using lines  6 - 6 ,  7 A- 7 A and  8 A- 8 A for corresponding sectional views of  FIGS. 6, 7A, and 8A . 
         [0065]      FIG. 17A  is also taken along line  6 - 6 , with respective enlarged views at  FIGS. 16, 7B and 8B . Further,  FIGS. 17A-17C , along with the exploded view in  FIG. 19 , depicts the preferred inventive structure added to a conventional follower  14  (shown in  FIG. 3B ), in accordance with the embodiment of the invention described in the parent application. 
         [0066]    Conventional followers typically have spacing arms  147 ,  148 ,  149  (depicted in  FIGS. 18 and 19 ) to properly maintain the follower  14  in proper position within the magazine casing  11 . These spacer arms are necessary in conventional weapons to prevent the upper support  15  from being pushed too far into magazine casing  11  and ensure that the follower  14  is guided properly in its upward movement as the rounds  300  are expended. Even if a conventional follower is not provided with spacing arms  147 ,  148 ,  149 , these could be added to facilitate installation of the structure preferred in the instant invention. 
         [0067]    Inset body  141  illustrated in  FIGS. 18 and 19 , is set between spacer arms  147  and  148 . Inset body  141  contains a concavity  142  in which a drive spring  144  and release prong  143  are placed. Release prong  143  extends through face plate  145 , which is attached to the inset body  141  by means of any securing fastener (in this case screws  146 A,  146 B,  146 C and  146 D are shown). 
         [0068]    Moreover, with the invention described in the parent application, it will be appreciated that the weapon operator does not have to press magazine release button  101  or pull ammunition magazine  10  from the magazine-well  110 . Rather, the entire operation is made automatic by the invention as described. Once the last round  300  leaves ammunition magazine  10 , whether this last round  300  has been fired or not, the automatic release and drop of the ammunition magazine  10  will occur without any effort on the part of the weapon operator. Moreover, the weapon operator can keep both hands in firing position and maintain the sighting of the weapon on the target downrange as the empty (i.e., spent) magazine is automatically released from the magazine-well. 
         [0069]    To reload, the weapon operator need only grab a new (i.e., loaded) ammunition magazine  10  and “slam it home” into the magazine-well or receiver  110 . This can be done while the weapon operator maintains the sighting of the weapon downrange on the target. 
         [0070]    It should be noted that there is one drawback with the invention of the parent application (i.e, when ammunition magazine  10  automatically drops from magazine-well  110  and the last round from the empty magazine is fired, the weapon bolt  108  will automatically close). Under many circumstances, this is a desirable operation in order to protect the firing chamber. However, when the speed of the reload cycle is important, this automatic operation is a drawback. More specifically, when the weapon operator is replacing the spent ammunition magazine, it is necessary for the weapon operator to replace the spent magazine with a loaded magazine before firing the last round or (if the last round is fired) to manually operate the bolt  108  to allow the first round in the new ammunition magazine to be chambered. Therefore, in the second case (i.e., the last round is accidently fired), the weapon must be taken from the downrange aiming position and the operator must use both hands to operate the bolt  108  to chamber the first round of the new ammunition magazine. Again, this is a drawback in those situations that require maintaining sight on a downrange target and adds time between firings. 
         [0071]    In order to address the drawback caused by the automatically closing bolt of the weapon  100 , when the spent ammunition magazine  10  automatically drops from magazine-well  110  and the last round is fired before loading a new magazine, the invention of the present application is used. In particular, the present invention keeps the weapon bolt back and the chamber open to receive a new round from a new ammunition magazine. Once the new ammunition magazine is engaged in the magazine-well and first round in position, the bolt will automatically close, chambering the round for firing. This is done without need to manually operate the bolt catch mechanism  160 , using operating button  161  as is required in the conventional art. To be clear, with the present invention, the bolt  108  does not have to be manually operated (with all of its undesirable consequences) by the weapon operator in order to chamber a new round from the newly loaded magazine. 
         [0072]    The goal of the present invention, which is further improvement from the operation of the invention of the parent application, is to keep the bolt open so that a round from the new ammunition magazine can be chambered without manually operating the weapon bolt. This is accomplished by a modification of the bolt catch mechanism  160  (conventionally depicted in  FIGS. 9A, 9B  and shown as preferably modified in  FIGS. 10A, 10B ), and located with respect to weapon casing/housing  120  depicted in  FIG. 12 . 
         [0073]    At the expense of being repetitive, the conventional bolt catch mechanism  160  of  FIGS. 9A, 9B  is operated using operating button  161  to move the internal bolt catch engagement interface  164  within the weapon to trigger the closing of the weapon bolt. The operation of the internal engagement interface  164  is already well-known, and does not change with the present invention. Likewise, the operating button  161  and pivot pin  165  (through pivot aperture  166 ) are used in the conventional manner, and are unchanged by the present invention. It is noted that plunger  162  (in  FIG. 11 ) and its associated spring  163  mounted below the pivot pin  165  are conventionally necessary for the return operation of the bolt catch mechanism  160  when its operating button  161  is pressed inward towards the weapon. 
         [0074]    As modified by the present invention, plunger spring  163  is not necessary due to pressure spring  175  (seen in  FIG. 12 ) which serves to keep bolt catch mechanism  160  from being easily operated, by adding pressure in the opposite rotational direction (i.e., above the pivot pin  165 ) behind the operating button  161  (positioned in depression  176  shown in  FIG. 10B ), for the bolt catch mechanism  160  to be moved in a manner whereby the internal engagement interface  164  releases the weapon bolt for closing. Moreover, pressure spring  175  and consequently the internal engagement interface  164 , hold the weapon bolt to keep it from closing. As a result, the bolt catch assembly  160  operating button  161  must be forcefully operated to manually overcome the pressure of spring  175 , thereby depressing it so that the weapon bolt will close. 
         [0075]    The present invention further includes a mechanism by which the weapon bolt is automatically closed in response to the new ammunition magazine  10  being placed and secured in position in the magazine-well  110 . This structure includes the extension arm  170  shown in  FIGS. 10A and 10B . The extension arm  170  has a U-shaped portion  172  with a beveled end  173  and an opposite connection portion  171  extending below the pivot pin  165  of the bolt catch assembly  160 . In operation, the beveled end  173  interacts with a detent structure  181  on the modified ammunition magazine  10 . More specifically, the extension arm  170  passes into the magazine-well  110  by means of aperture  180  as shown in  FIGS. 8A, 8B, 16, 17A, 17B and 17C . There is contact interaction between the beveled end  173  of extension arm  170  and the detent  181  of the ammunition magazine  10  as the magazine is pushed and secured into magazine-well  110 . This is crucial to the operation of the present invention. 
         [0076]    Specifically, the extension arm  170  facilitates the key operation of the present invention, in that beveled edge  173  interfaces with detent  181  on case  11  of the ammunition magazine  10 . The detent is positioned so that it is aligned opposite aperture  180  in the ammunition magazine-well  110 . The beveled end  173  with extension arm  170 , therefore, extends through aperture  180  to interface with detent  181 . Therefore, as the ammunition magazine  10  is moved upwards and into magazine-well  110 , the ramped profile of detent  181  contacts and forces the beveled end  173  (and thus extension arm  170 ) to rotate outwards through aperture  180  about pivot pin  165 , as best seen with reference to  FIGS. 17B and 17C . As a result, inserting the new ammunition magazine  10  into the magazine-well  110  automatically operates the bolt catch mechanism  160  (and thus releases the contact is interaction between internal engagement interface  164  with the weapon bolt  108  to close the firing chamber  107 ) without any further action on the part of the weapon operator. Notably, the automatic removal of the spent magazine as described above causes rotation in the opposite direction (i.e., inwards through aperture  180  about pivot pin  165 ) for contact engagement between the internal engagement interface  164  and the weapon bolt  108 , to hold the firing chamber  107  open. 
         [0077]    The placement and dimensions of extension arm  170  are adaptable, and can vary from weapon to weapon. The inventive adaptations described above are not difficult to apply to the M4 family of weapons.  FIGS. 6 and 16 , along with  FIGS. 17A-17C , depict the placement of extension arm  170  with regard to the height and spaced relationship of the weapon  100  and ammunition magazine  10 . These figures also depict the point at which aperture  180  permits the interface between the beveled end  173  of the extension arm  170  and the casing  11  of ammunition magazine  10 . Also depicted is the relationship between the magazine follower  14  and the magazine holding extension  105  that interfaces with casing  11 . Thus, the vertical relationships between the weapon  100 , the ammunition magazine  10 , and all of the inventive features of both the present application and the parent application are fully depicted. Further,  FIGS. 8A and 8B  illustrate the horizontal placement of the inventive extension arm  170  with respect to weapon  100  and ammunition magazine  10 . It should be understood that with different variations of the M4, as well as other types of automatic and semi-automatic weapons, the size of extension arm  170  can vary to accommodate each situation. 
         [0078]    The modifications to the instant bolt catch mechanism  160  are further depicted in the exploded view shown in  FIG. 12 . The addition of pressure spring  175  and extension arm  170  are modifications that do not drastically alter the conventional bolt catch mechanism  160 , and are thus implemented without much difficulty. However, these inventive additions provide a profound change in the operation of weapon  100 . 
         [0079]    To be clear, in operation, as the magazine  10  is forced upward in the magazine-well  110 , the detent  181  in the magazine casing  11  ramps outward and pushes against the beveled end  173  of extension arm  170  passing through aperture  180 . More specifically, the depth of the detent  181  is much greater near the top of the magazine where it first makes contact with beveled end  173 .  FIG. 13  depicts this initial contact when the ammunition magazine  10  is being inserted into magazine-well  110 . As also depicted in  FIG. 13 , pressure spring  175  keeps operating button  161  of bolt catch mechanism  160  from being easily pushed towards the casing/housing  120  of the weapon  100 . The beveled end  173  of extension arm  170  is on the beginning of detent  181 , and so very little force is being exerted on beveled end  173  by detent  181  against the spring  175 . 
         [0080]    Since the detent  181  ramps outward (extending down the magazine casing  11 ), the detent  181  forces extension arm  170  outward by pushing beveled end  173  further out of aperture  180 , as the ammunition magazine  10  is pushed upward into the magazine-well  110 . The force created by the movement of the ammunition magazine  10  into the magazine-well  110  is sufficient to overcome the force of pressure spring  175 , moving the operating button  161  towards the weapon housing  120 , thereby operating the bolt catch mechanism to close the firing chamber  107 . This does not occur, however, until the ammunition magazine  10  is all the way into the magazine-well  110  (i.e., in the seated position such that the first round  300  in the ammunition magazine simultaneously enters the firing chamber  107  as it closes). 
         [0081]      FIG. 14  best depicts the point in the operation in which the ammunition magazine  10  has been fully inserted into the magazine-well  110 . As indicated by the arrows, the force exerted by the outwardly ramped detent  181  forces extension arm  170  outward, driving operating button  161  against the pressure of pressure spring  175 . The result is that the bolt closes on round  300  as soon as the ammunition magazine  10  is fully engaged in the magazine-well  110 . This operation is automatic upon seating the new ammunition magazine  10  fully into the magazine-well  110 , without the weapon operator having to manually conduct any other action. This means that with one hand, the weapon operator can replace an ammunition magazine and automatically operated the bolt  108 . Moreover, the weapon operator does not have to divert attention from sighting downrange. 
         [0082]    The advantage of the instant invention is clear. When combined with the automatic magazine release mechanism of the parent application (wherein the ammunition magazine automatically releases and falls from the magazine-well  110  without manual effort on the part of the weapon operator), the present automatic bolt release mechanism described herein allows the weapon operator to fire the last round of the spent ammunition magazine, insert the new (i.e., loaded) magazine, and continue operation. The weapon bolt, which would normally close upon firing the last round, is automatically held open, and the weapon operator does no more than slip and seat another ammunition magazine  10  into the magazine-well. Placement of the loaded magazine  10  fully within the magazine-well  110  automatically operates the weapon bolt  108  to chamber the first round  300  of said magazine. 
         [0083]      FIG. 16  depicts an enlarged sectional view of  FIG. 6  (based upon the lines in  FIG. 5 ) and illustrates the top of the ammunition magazine  10  seated in magazine-well  110 . The relationship between magazine release mechanism (holding extension  105 ) and the ammunition magazine casing  11  is clearly shown. Also depicted is the location of extension arm  170  passing through aperture  180  and the ramped shape of detent  181  in magazine casing  11 . Further illustrated is follower  14  pushing rounds  300  upward and into the firing chamber  107 . 
         [0084]    In operating sequence,  FIG. 17A  shows an empty chamber (i.e., the last round  300  shown in  FIG. 16  has been pushed into the firing chamber by follower  14  and fired). At the point that last round  300  is pushed into the firing chamber  107 , the follower  14  has reached a position where plunger or prong  143  pushes against holding extension  105 , so as to release the empty ammunition magazine  10  from magazine-well  110 . The spent magazine  10  will begin to fall from the magazine well  110 . Notably, a slot or depression  18  is preferably included in the magazine casing  11  (as seen in  FIGS. 15A, 15B , after catch lip  17  and aperture  16 —separated by stop  19 ) to eliminate frictional contact by holding extension  105  (i.e., to provide free-fall of the spent magazine as extension  105  returns to its extended position as the magazine begins its descent from the magazine-well  110 ). 
         [0085]    With further reference to  FIGS. 17A  (as well as the enlarged illustrations at  FIGS. 17B, 17C ), as the spent magazine  110  begins its descent from the magazine-well  110 , the extension arm  170  (which starts from the position depicted in  FIG. 17A, 17B ) begins to rotate bolt catch mechanism  160  inward about pivot pin  165 . Now, viewing  FIG. 17C , the release and descent of the spent magazine  10  from the magazine-well has already occurred (i.e., the ammunition magazine  10  is moving downward by gravity out of the magazine-well  110 ). It should be noted that extension arm  170  continues to press against casing  11  of the descending magazine  10 . Moreover, the force of pressure spring  175  against the back of operating button  161  rotates the extension arm  170  and its beveled end  173  further into aperture  180  until the end of the descending magazine passes. Then, upon firing the last round of the empty magazine  10 , the bolt catch mechanism  160  will have pivoted into position to hold the bolt  108  and, consequently, the firing chamber  107  open. 
         [0086]    As a result, the weapon operator need use only one hand for reloading, and does not have to deviate from sighting downrange from a fully operational firing position. The result is a much faster reloading cycle that does not interfere with the weapon operator&#39;s ability to maintain focus downrange. The combination of the invention of the parent application with that of the present application creates a streamlined system for expedited reloading that reduces the effort required by the weapon operator. Importantly, the weapon operator need not lose focus on downrange targets. 
         [0087]    All documents cited in the Detailed Description of the Preferred Embodiment are, in relevant part, incorporated herein by reference; the citation of any document is not to be construed as an admission that it is prior art with respect to the present invention. To the extent that any meaning or definition of a term in this document conflicts with any meaning or definition of the same term in the document incorporated by reference, the meaning or definition assigned to that term in this document shall govern. 
         [0088]    While the preferred embodiments have been described by way of example, the present invention is not limited thereto. Rather, the present invention should be understood to include any and all limitations, modifications, variations, embodiments, derivations, and adaptations that would occur to one skilled in this technology after understanding the present invention. Accordingly, the present invention should be limited only by the breadth of the following claims. All changes that come within the meaning and range of equivalency of the claims are to be embraced within their scope.