Patent Publication Number: US-7219462-B2

Title: Receiver assembly for firearm

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to firearms, more particularly to a receiver assembly for a firearm. 
   2. Description of Related Art 
   The use of a receiver on a military style firearm is known. Typically, the receiver is configured to receive a magazine. Differences exist, however, in how the receiver functions and the type of magazine that the receiver can accept. 
   A major factor affecting the design of the receiver is the type of magazine. High capacity magazines were and are typically manufactured in one of two styles. One style relates to a magazine having a retaining feature and a locking feature. Thus, the first type of magazine can be referred to as a dual feature magazine. Examples of the first type include a tabbed magazine such as might be used on an AK-47 rifle. The other style relates to a magazine that does not use both a retaining and locking feature (i.e. a non-dual featured magazine). Due to differences in the geometry of the two different styles of magazine, two general methods of inserting the magazine into the receiver exist, depending on the style of magazine being used. 
   A first method of magazine insertion is to insert one end of a tabbed magazine into the receiver. The tab on the tabbed magazine catches on a tab engaging feature in the receiver and the tab is used as a pivot point for rotating the tabbed magazine into the receiver until a magazine catch engages a locking feature of the tabbed magazine. Thus, in the first method the tabbed magazine is held in the receiver well by the tab engaging feature engaging the tab (i.e., the retaining feature), by the magazine catch engaging the locking feature, and by the two walls of the receiver well. 
   A second method of magazine insertion is to insert a non-tabbed magazine into the receiver by sliding the non-tabbed magazine straight into the receiver well and using a magazine catch to engage a cutout in a wall of the non-tabbed magazine. Unlike the first method, in the second method there is no need to rotate or rock the magazine into the receiver well. Thus, the second method provides a simpler motion for inserting the magazine that can be beneficial when attempting to quickly insert the magazine in the firearm. 
   Once the magazine is inserted, the firearm can be discharged repeatedly until all the cartridges contained within the magazine are fired. After the last cartridge is fired, a bolt stop is pushed into a blocking position by a cartridge follower and the bolt stop prevents the bolt assembly from moving forward into the battery position. Once a new magazine has been inserted into the receiver, a bolt stop button can be activated. The bolt stop button retracts the bolt stop and allows the bolt assembly to move forward into the battery position, the bolt assembly stripping off a cartridge from the new magazine in the process. It would be preferable to allow ambidextrous operation of the bolt stop button. 
   Before the new magazine can be inserted, however, the old magazine must be removed. Two general methods exist for removing the magazine from the receiver, depending on whether the magazine is a dual featured magazine such as a tabbed magazine, or is a non-dual featured magazine. With a dual-featured magazine, a magazine release button is activated with the one hand and the dual-featured magazine is rotated out of the receiver with the other hand. Thus, the method of removing a dual-featured magazine requires two hands. 
   With a non-dual featured magazine, the magazine release button is activated with one hand and the non-dual featured magazine drops free of the receiver. Thus, with a non-dual featured magazine the removal of the empty magazine is a one hand operation. While the release is a one hand operation, the magazine release button is designed to be operated by either the right or left hand, thus limiting certain ergonomic aspects of a firearm, including the ability for the particular firearm to be readily used in either hand. As can be appreciated, however, the method of removing a non-dual featured magazine by simply pressing a button does have certain advantages. For example, the one handed release of a magazine is useful to individuals, whom for medical reasons, have trouble grasping the magazine with the off hand. In addition, the ability to quickly remove an empty magazine can decrease the overall time it takes to go from an empty magazine to a full magazine. Decreasing this transition time can be valuable to members of the armed forces engaged in hostile combat. 
   As previously mentioned, both tabbed and other style magazines were produced for use in appropriately designed receivers. Due to historical factors, the quantity of high capacity tabbed magazines currently in existence is greater than the quantity of high capacity magazines of other styles. Thus, the cost of high capacity magazines made in styles other then the tabbed style has risen because of the limited supply and the desirability of the magazine quick release feature. The cost of high capacity tabbed magazines, on the other hand, has remained relatively inexpensive. A receiver that accepts the high capacity tabbed magazine could provide the user of the firearm with a decreased operating cost. 
   BRIEF SUMMARY OF THE INVENTION 
   In an aspect of the present invention, a receiver well is configured to receive a tabbed magazine, the tabbed magazine having a locking feature. In an exemplary embodiment, the receiver well has a slot for receiving the tab on the tabbed magazine so that the tabbed magazine may be slid directly into the receiver well without the need to rotate the magazine about the tab. In an exemplary embodiment, the internal walls of the receiver well along with the magazine catch are configured to support the magazine when the magazine is in the inserted position. Thus, a tabbed magazine may be inserted into the receiver well without the need to rotate the tabbed magazine about the tab during the insertion. 
   In an aspect of the present invention, the receiver is equipped with a magazine release button that can be operated from either side of the firearm. Thus, the firearm can be used by someone in either the left or right hand while preserving the ergonomic aspects that allow for ease of activating the magazine release button. 
   In an aspect of the present invention, a receiver is equipped with a bolt stop release button. In an exemplary embodiment, the bolt stop button can be activated from either side of the firearm by pressing the bolt stop button downward. Thus, the firearm can be used by someone in either the left or right hand while preserving the ergonomic aspects that allow for ease of releasing the bolt stop. 
   In an aspect of the present invention, a receiver is configured so as to allow one-handed release of a dual-featured magazine. In an exemplary embodiment, a receiver well includes a slot and is configured so that when a magazine catch disengages a locking feature on a tabbed magazine, the magazine drops out of the receiver well. Thus, a dual-featured magazine can be removed from the receiver well with one hand and without the need to rotate the magazine out of the receiver well. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention is illustrated by way of example and not limited in the accompanying figures in which like reference numerals indicate similar elements and in which: 
       FIG. 1  illustrates an elevation view of an exemplary firearm for use with the teachings of the invention. 
       FIG. 2  illustrates an isometric partial view of an exemplary firearm, including the receiver, a portion of the buttstock, a portion of a magazine, and a pistol grip. 
       FIG. 3   a  illustrates a partial side view of an exemplary embodiment of a tabbed magazine. 
       FIG. 3   b  illustrates a partial plan view of the tabbed magazine depicted in  FIG. 3   a.    
       FIG. 4   a  illustrates a partial plan view of an embodiment of the receiver. 
       FIG. 4   b  illustrates a partial plan view of the receiver depicted in  FIG. 3   a  with the tabbed magazine inserted into the receiver. 
       FIG. 5  illustrates a cutaway side view the magazine catch engaging the tabbed receiver. 
       FIG. 6   a  illustrates a partial left isometric view of an exemplary embodiment of the receiver. 
       FIG. 6   b  illustrates a partial right isometric view of the receiver depicted in  FIG. 6   a.    
       FIG. 7  illustrates an isometric view of an exemplary magazine catch and associate components. 
       FIG. 8   a  illustrates a side view of an exemplary embodiment the magazine release system, with the magazine release button not activated. 
       FIG. 8   b  illustrates a side view of the magazine release system depicted in  FIG. 8   a  with the magazine release button activated. 
       FIG. 9   a  illustrates a front view of an exemplary bolt stop system. 
       FIG. 9   b  illustrates a side view of the bolt system depicted in  FIG. 10   a.    
       FIG. 10   a  illustrates a partial isometric view of an exemplary embodiment of the receiver after the last cartridge has been removed from the magazine but the bolt assembly is still in the battery position. 
       FIG. 10   b  illustrates a partial isometric view of an exemplary embodiment of the receiver with the bolt assembly moving toward the recoiled position. 
       FIG. 10   c  illustrates a partial isometric view of an exemplary embodiment of the receiver with the bolt assembly up against the bolt stop. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1  illustrates a side view of an embodiment of a firearm  5 . The firearm, in a known configuration, includes a buttstock  10 , a grip  12 , a receiver  14 , a bolt assembly  16  (shown in broken line), and a barrel  18 . 
   In operation, the user can hold the grip  12  in one hand while pressing the buttstock  10  against the users&#39; shoulder. The buttstock  10  and the grip  12  are mounted to the receiver  14 . Generally, the receiver  14  is configured to receive the bolt assembly  16  and the barrel  18 . In operation, the bolt assembly  16  strips a cartridge from the magazine  20  and moves the cartridge forward into the barrel  18  as the bolt assembly  16  moves toward a battery position. Once the bolt assembly  16  is in the battery position, the user can activate a trigger  22 , which can be mounted to the receiver  14 . The trigger  22  releases a cocked hammer and the hammer strikes a firing pin. The firing pin moves forward and makes contact with the cartridge. The contact between the firing pin and the cartridge causes the cartridge to fire and the resultant explosion forces a bullet out the end of the barrel  18  along a forward path dependent on the direction the barrel  18  is pointing. The resultant explosion also causes the bolt assembly  16  to recoil in a backward direction opposite of the direction of bullet travel. The movement of the bolt assembly  16  allows the spent cartridge to be ejected. An operation spring (not shown) opposes the backward travel of the bolt assembly  16  and after the operation spring is sufficiently compressed, i.e., the bolt assembly  16  is in a recoiled position, the compressed operation spring moves the bolt assembly  16  forward so that another cartridge can be stripped from the magazine  20  and the bolt assembly  16  can be returned to the battery position. 
   As previously described, the receiver as depicted in  FIG. 1  can be designed to receive one of two types of magazines.  FIG. 2  depicts an isometric partial view of an exemplary embodiment of the firearm  5  illustrated in  FIG. 1 . The partial firearm, as depicted, comprises a buttstock  10 , a grip  12 , and a receiver  50  and a tabbed magazine  100 . Other components of the firearm  6 , including a barrel  18  and a bolt assembly  16 , are not shown. A forward direction can be defined as the direction from the buttstock  10  towards the barrel (i.e., the direction the bullet travels in operation). A backwards direction can be defined as the opposite of the forward direction. Right and left directions can be defined with reference to the forward direction. 
   As depicted in  FIG. 2 , the receiver  50  includes a trigger  51  and a hammer  52 . As depicted, the receiver  50  also includes a magazine release button  61 , a bolt stop  71  and a bolt stop release button  73 . The tabbed magazine  100  rests inside of the receiver well  81 . The magazine release button  61 , when depressed, allows the tabbed magazine  100  to be removed from receiver well  81 . As depicted, the receiver has a chamfer near the bottom for ease of inserting a magazine into the receiver well. 
     FIG. 3   a  depicts a partial side view of a tabbed magazine  100 , which includes a tab  120  located on a first wall  111  of the tabbed magazine  100 . Two general patterns of tabbed magazines exist, the English pattern and the Metric pattern. Dimensionally, the two patterns are basically the same except for the size of the tab  120 . The English pattern tabbed magazine uses a brazed-on tab  120  where the tab  120  extends about 0.06 inches outwardly from the first wall  111 . The metric pattern tabbed magazines uses a formed tab  120  that extends about 0.02 inches outwardly from the first wall  111 . Thus, the brazed-on tab  120  extends further from the magazine wall  111  then the formed tab  120 . As illustrated in  FIG. 3   a , the tab  120  on the tabbed magazine  100  is brazed-on rather then being formed out of the first wall  111  of the tabbed magazine  100 . On a third wall  113 , the third wall  113  being opposite the first wall  111  and tab  120 , a rib  115  extends along the third wall  113 . A locking feature  116  is cut into the rib  115 . Locking feature  116  is depicted as a cutout in the rib  115  but could also be designed as a welded on or machined piece fastened to the tabbed magazine  100 . In an alternative embodiment, not shown, a dual-featured magazine could have a retaining feature such as a tab, a detent or some other known feature. The magazine would also have a locking feature. Preferably, the retaining feature and the locking feature would be on opposite sides of the magazine so as to provide additional stability. 
     FIG. 3   b  depicts a plan view of the tabbed magazine  100  depicted in  FIG. 3   a . As depicted, the tabbed magazine  100  includes the first wall  111 , a second wall  112 , the third wall  113 , and a fourth wall  114 . The tabbed magazine  100  also includes the rib  115 . A magazine profile  110  can be defined by the combination of the outer surfaces of the first wall  111 , the second wall  112 , the third wall  113 , the fourth wall  114 , and the rib  115 . As can be appreciated, the tab  120  extends outwardly from the first wall  111  beyond the magazine profile  110 . 
     FIG. 4   a  illustrates a partial plan view of an exemplary embodiment of receiver  50 . The receiver well  81  can be configured to be slightly larger but closely match the physical dimension of the magazine profile  110 . The receiver well  81  can include a receiver stop  83 . The receiver stop  83  is preferably configured to extend into the receiver well  81  past the outer boundary of the magazine profile  110 . In operation, the receiver stop  83  prevents the tabbed magazine  100  from being inserted too far into the receiver well  81 . The receiver well  81  further includes a receiver slot  82 , the receiver slot  82  configured to allow the tabbed magazine  100 , which includes the tab  120 , to be inserted straight into the receiver well  81  without the need to rotate the tabbed magazine  100  about the tab  120 . 
     FIG. 4   b  illustrates a partial plan view of an exemplary embodiment of the receiver  50  with the tabbed magazine  100  inserted into the receiver well  81 . As depicted, the magazine profile  110  interfaces with the receiver well  81 , the receiver well  81  being configured to provide surfaces that can support the magazine profile  110 . Preferably, the clearance between the receiver well  81  and the tabbed magazine  100  is small so as to minimize movement of the tabbed magazine  100  once it is inserted into the receiver well  81 . The close fit between the internal surfaces of the receiver well  81  and the tabbed magazine  100  can control forward, backward, and right/left movement of the tabbed magazine  100 . The receiver slot  82  can be configured to allow the tabbed magazine  100  equipped with tab  120  to be inserted into the receiver well  81  while avoiding contact between the tab  120  and the receiver well  81 . Thus, as depicted, the tabbed magazine  100 , which includes the tab  120 , could be slid directly into the receiver well  81  without the need to rotate tabbed magazine  100  about the tab  120 . As can be readily appreciated, if the receiver slot  82  is configured to receive the brazed-on tab, the receiver slot  82  will also receive the formed tab, which does not extend outwardly from the magazine  100  as far as the brazed-on tab. It is also preferable to have a chamfer  99  ( FIG. 6   a ) on the bottom of the receiver well  81  so as to allow the tabbed magazine  100  to be easily inserted into the receiver well  81 . 
   In an alternative exemplary embodiment, the receiver well  81  could include a rib that could be used, in operation, to control movement of the tabbed magazine  100 . In such an example, the rib could be in close proximity or contact with the tabbed magazine  100  once the tabbed magazine  100  was inserted into the receiver well  81 . Numerous other geometries of the receiver well  81  exist for supporting the magazine, thus, the described geometries are illustrative. 
     FIG. 5  illustrates a cutaway side view of the tabbed magazine  100 , a magazine catch  63  and and associated components. As depicted, the tabbed magazine  100  is in the inserted position and magazine catch  63  is engaged in the locking feature  116 . Thus, the magazine catch  63 , when engaged in the locking feature  116 , can prevent downward movement of the tabbed magazine  100 . Thus, movement of the tabbed magazine  100  can be controlled once the tabbed magazine  100  is inserted into the receiver well  81  by the geometry of the receiver well  81 , the receiver stop  83  and the magazine catch  63 . 
   After a loaded tabbed magazine  100  is inserted into the receiver well, the firearm  5  can be fired. As is readily apparent, even high capacity magazines have a limited supply of cartridges. Once all the cartridges are fired and the tabbed magazine  100  is empty, the empty tabbed magazine  100  must be removed before a loaded tabbed magazine  100  can be inserted. 
     FIG. 6   a  illustrates a right isometric view of an exemplary embodiment of the receiver  50 . As depicted, magazine release button  61  is located above and forward of trigger  51 . Pushing the magazine release button  61  inward would cause the magazine catch  63  to release. 
     FIG. 6   b  illustrates a left isometric view of the embodiment depicted in  FIG. 6   a . As depicted, the magazine release button  61  on the left side is located opposite the magazine release button  61  on the right side. Pushing the magazine release button  61  on the left side inward would also cause the magazine catch  63  to release. 
   Thus, as depicted in  FIGS. 6   a  and  6   b , the magazine release button  61  can be pushed inward on either side of the receiver  50  so as to release the magazine catch  63  and therefore provide an ambidextrous release feature. Regardless of whether the magazine release button  61  is pressed on the left or the right side of the receiver, pushing the magazine release button  61  allows a dual-featured magazine, such as the tabbed magazine  100  to be removed from the receiver  50 . In an exemplary embodiment, pushing the magazine release button  61  causes the tabbed magazine  100  to drop out of the receiver. Thus, in an exemplary embodiment, the dual-featured magazine can be removed with one hand. As can be appreciated, the magazine release button  61  can be depressed with the trigger finger of the user. Thus, as depicted, the ambidextrous nature of the magazine release button  61  can allow the user of the firearm to hold the firearm in either hand. 
     FIGS. 6   a  and  6   b  also depict an exemplary embodiment of a bolt stop button  73  (discuss below) located on the right side and the left side of the receiver  50 . Thus, in an exemplary embodiment of the present invention, the magazine release button  61  and the bolt stop button  73  are located on both the left side and the right side of the receiver  50  and thus the firearm. As depicted, the inclusion of the bolt stop button  73  and the magazine release button  61  on both the left and the right side provides a receiver  50  suited for use in either hand, enhancing the ergonomics of the firearm. 
     FIG. 7  illustrates an isometric view of the magazine catch  63  and associated components. Magazine catch  63  is mounted to the receiver  50  via a magazine catch pin  65 . Magazine catch spring  64  is mounted so as to bias the magazine catch  63  to rotate about the magazine catch pin  65  toward a magazine release pin  62  and into the receiver well  81 . As depicted, magazine release button  61  is mounted to magazine release pin  62 . Depressing the magazine release button  61  causes the magazine release pin  62  to translate. The magazine catch pin  62  has a release pin v-notch  66  that interfaces with the magazine catch  63 . The release pin v-notch  66  has a first smaller diameter  68  and a second larger diameter  69  on both the left and right side of the first smaller diameter. The magazine catch  63  is biased toward the release pin v-notch  66  by a magazine spring  64  so that the magazine catch  63  exerts a force on the magazine release pin  62 . During translation of the magazine release pin  62 , the magazine catch  63  moves from the first smaller diameter to the second larger diameter. Thus, translation of the magazine release pin  62  causes the magazine catch  63  to rotate about the magazine catch pin  65 , the rotation opposed by the magazine catch spring  64 . The rotation of the magazine catch  63  causes the magazine catch  63  to disengage from the locking feature  116  on the tabbed magazine  100 . Once the user releases the magazine release button  61 , the force exerted on magazine release pin  62  by the magazine catch  63 , the magazine catch  63  being biased by the magazine catch spring  64 , causes the magazine release pin  62  to translate so that the magazine catch  63  can return from the second larger diameter  69  to the first smaller diameter  68  of the v-notch pin  66 . 
   As depicted, the release pin v-notch  66  interfaces with a corresponding surface  67  on the magazine catch  63 . When the surface  67  engages the first smaller diameter  68  the magazine catch  63  is in the engaged position. When the surface  67  engages the second larger diameter  69  this position corresponds to the magazine catch  63  being in the disengaged position. 
   Also depicted in  FIG. 7  is a bolt stop  71 , a bolt stop pin  74 , a bolt stop member  72 , and the bolt stop button  73 . These components will be discussed in greater detail below. 
   The insertion of a magazine can cause the magazine catch  63  to rotate about the magazine catch pin  65  away from the magazine release pin  62  until the magazine is inserted far enough into the receiver well  81  so that the magazine catch  63  can engage the locking feature  116 . Thus, upon full insertion of the tabbed magazine  100 , the magazine catch spring  64  will force the magazine catch  63  back to the engaged position. 
     FIG. 8   a  illustrates a side view of an exemplary embodiment of the magazine release system, including the magazine release button  61 , the magazine catch  63  and the magazine catch pin  65 . As depicted in  FIG. 8   a , the magazine release button  61  is not depressed and magazine catch  63  is in the engaged position. In operation, the magazine catch  63  supports a magazine by engaging with the locking feature  116  when the magazine is inserted. 
     FIG. 8   b  illustrates a side view of the embodiment depicted in  FIG. 8   a . As depicted, the magazine release button  61  is depressed. Depressing the magazine release button  61  causes the magazine catch  63  to rotate about the magazine catch pin  65  away from the engaged position. In operation, this rotation can disengage the magazine catch  63  from the locking feature  116  so as to allow the dual-featured magazine to drop free of the receiver  50 . 
     FIG. 9   a  illustrates a front view of the bolt stop  71  and associated components. In operation, bolt stop member  72  can be translatably mounted to the receiver  50  so that bolt stop member  72  can move along its longitudinal axis. As depicted, bolt stop button  73  is mounted on both sides of bolt stop member  72 . Bolt stop member  72  is connected to bolt stop  71 . In an exemplary embodiment, bolt stop button  73  is located on both sides of the receiver so as to provide an improvement over existing firearms that could not provide such an ergonomic feature. As can be readily appreciated, having the bolt stop button  73  on both sides of the receiver allows the same firearm to be more readily operated in both the left hand and the right hand. 
     FIG. 9   b  illustrates a side view of the embodiment depicted in  FIG. 9   a . As depicted, bolt stop pin  74  is mounted to bolt stop member  72 . Thus, as depicted, upward vertical movement of the bolt stop pin  74  causes the bolt stop member  72  to translate in an upward vertical direction, where the upward vertical movement of bolt stop member  72  causes the bolt stop  71  to move from a non-blocking to a blocking position. Likewise, downward translation of the bolt stop member  72 , by pressing down on the bolt stop button  73  causes the bolt stop  71  to move toward a non-blocking position. In operation, a spring can be used to bias the bolt stop  71  towards the non-blocking position. 
     FIG. 10   a  illustrates a partial isometric view of an exemplary embodiment of receiver  50  after the last cartridge has been removed from the tabbed magazine  100  with a bolt assembly  150  in a battery position. In operation, a cartridge follower presses upward against the bolt stop pin  74  (not shown) when the last cartridge is removed from the magazine. As described in  FIGS. 9   a  and  9   b , the bolt stop pin  74  is mounted to the bolt stop member  72 . Bolt stop member  72  connects bolt stop  71  to bolt stop button  73 . Therefore, by pushing upward on bolt stop pin  74 , the cartridge follower exerts an upward force on the bolt stop  71 . Movement of the bolt stop  71  is inhibited by the presence of a bolt assembly  150  in a battery position. Thus, when the bolt assembly  150  is in the battery position, as shown in  FIG. 10   a , the bolt assembly  150  is in the way of upward movement by the bolt stop  71 . Once the last cartridge is fired, the bolt assembly moves from the battery position toward a recoiled position. 
     FIG. 10   b  illustrates a partial isometric view of the embodiment shown in  FIG. 10   a , with the bolt assembly  150  moving towards the recoiled position. As is readily apparent, once the bolt assembly  150  moves far enough toward the recoiled position, the bolt stop  71  can move in an upward direction. The force exerted on the bolt stop pin  74  by the cartridge follower will direct the bolt stop member  72 , the bolt stop button  73 , and the bolt stop  71  upward. Thus, the bolt stop  71  can travel upward from a non-blocking position to a blocking position. As previously discussed, the operation spring biasing the bolt assembly  150  toward the battery position compresses as the bolt assembly  150  moves toward the recoiled position. Once the bolt assembly  150  reaches the recoiled position, the compressed operation spring directs the bolt assembly  150  back towards the battery position. 
     FIG. 10   c  illustrates an isometric view of the embodiment depicted in  FIG. 10   b , with the bolt assembly  150  in contact with the bolt stop  71 . Thus, the forward movement of the bolt assembly  150  is interrupted by contact with the bolt stop  71  so that the bolt assembly  150  is between the recoiled position and the battery position. The cartridge follower still exerts an upward force upon the bolt stop pin  74  and the compressed operation spring still exerts a forward force on the bolt assembly  150 . 
   As discussed above, after the last cartridge has been fired, the empty tabbed magazine  100  must be removed before the loaded tabbed magazine  100  can be inserted. As discussed above, depressing the magazine release button  61  disengages the magazine catch  63  so that the tabbed magazine  100  can be removed. In an exemplary embodiment, the pressing of the magazine release button  61  causes the tabbed magazine  100  to drop out of the receiver well  81 . The tabbed magazine can drop free because the tab is not used to retain the magazine. Thus, the tabbed magazine  100  will be directed out of the receiver well by the force of gravity and the force exerted on the bolt stop pin  74  by the cartridge follower. Thus, in an exemplary embodiment, depressing the magazine release button  61  will cause the empty tabbed magazine  100  to be ejected from the receiver well  81 . In an alternative embodiment, a dual-featured magazine can be ejected from the receiver well  81  in a similar manner. 
   Once the empty tabbed magazine  100  has been removed from the receiver well  81 , the loaded tabbed magazine  100  can be inserted. After inserting the loaded tabbed magazine  100 , the bolt assembly  150 , which presses against the bolt stop  71 , can be moved toward the battery position. 
   To allow the bolt assembly  150  to move to the battery position, the bolt stop  71  can be moved downward out of the blocking position.  FIG. 10   c  illustrates an exemplary embodiment of the bolt stop button  73  connected to the bolt stop  71  via the bolt stop member  72 , with the bolt stop  71  in the blocking position. As depicted, the bolt stop  71  can be moved downward by exerting a downward force on the bolt stop button  73 . The downward movement of the bolt stop button  73  will cause a resultant downward movement of the bolt stop  71  because the bolt stop member  72  connects the bolt stop button  73  to the bolt stop  71 . Thus, the bolt stop button  73  can release the bolt assembly  150  so that the bolt assembly  150  can move to the battery position and in the process the bolt assembly  150  can strip a cartridge from the tabbed magazine  100 . 
   In an exemplary embodiment, a firearm  5  includes a receiver  50  with a receiver well  81  having a receiver slot  82 , an ambidextrous magazine release button  61 , and an ambidextrous bolt stop button  73 . In such a receiver, a tabbed magazine  100  can be inserted directly into the receiver well  81  without the need to rotate the tabbed magazine  100 . Additionally, after firing the last cartridge in the tabbed magazine  100 , the empty tabbed magazine  100  can be ejected from the receiver well  81  by pressing on the ambidextrous magazine release button  61  without the need to rock the tabbed magazine out of the receiver well  81 . After ejecting the empty tabbed magazine  100  and inserting a loaded tabbed magazine  100 , the ambidextrous bolt stop button  73  can be actuated so as to allow the bolt assembly  150  to return to the battery position, stripping a cartridge from the tabbed magazine  100  in the process. Thus, in an exemplary embodiment, the firearm  5  is suited for rapid tabbed magazine exchange and is further suited for use in either hand (i.e. is suited for ambidextrous use while preserving the ability to rapidly exchange a empty tabbed magazine  100  for a loaded tabbed magazine  100 ). 
   The present invention has been described in terms of preferred and exemplary embodiments thereof. Numerous other embodiments, modifications and variations within the scope and spirit of the appended claims will occur to persons of ordinary skill in the art from a review of this disclosure.