Patent Publication Number: US-10788278-B2

Title: Latched charging handle with mechanical advantage separator

Description:
BACKGROUND 
     The present disclosure pertains generally to firearms. In particular, the present disclosure pertains to charging handles for firearms. 
     Firearms occasionally experience malfunctions. There are numerous types and causes of malfunctions. One particular type of malfunction is a stuck case malfunction. In a stuck case malfunction, the firearm fails to extract a cartridge-case that has become lodged in the chamber. The cartridge-case can become lodged due to a number of reasons. For example, the cartridge case may be lodged due to over-expansion of the cartridge-case upon firing of the firearm. 
     As a stuck case malfunction prevents further loading of cartridges into the chamber, the firearm cannot be fired until the stuck case is extracted. The consequences for failing to successfully extract a stuck case can range from the inconvenient, to the catastrophic. In a combat situation, failing to clear a stuck case malfunction can be life threatening. Accordingly, there is a desire to be able to clear such malfunctions quickly and easily when they occur. 
     When a stuck case malfunction is encountered in an AR style firearm (e.g., AR-15 or M-16), a common method currently employed to clear it is to force the charging handle rearward while simultaneously slamming the butt of the rifle on the ground. In some instances, an operator may need to perform this maneuver repeatedly before the bolt successfully opens and/or extracts the cartridge-case from the chamber of the firearm. Unfortunately, this method of clearing a stuck case malfunction can be dangerous and potentially damaging to the rifle. Additionally, in some instances, this method is unsuccessful in clearing a stuck case malfunction. Accordingly, there is a desire for new devices and methods for clearing such a malfunction. 
     SUMMARY OF THE PRESENT INVENTION 
     The present disclosure pertains generally to firearms. In particular, the present disclosure pertains to charging handles for firearms. More specifically, the present disclosure provides charging handles having structure, such as a simple machine, for providing a mechanical advantage when opening a bolt of a firearm, especially firearms experiencing a stuck case malfunction. 
     For simplicity, the present disclosure has been described with reference to clearing a stuck case malfunction in a firearm. However, the present disclosure should not be limited as such. The present disclosure is envisioned as being useful for clearing other malfunctions as well. 
     Additionally while not limited to such, the present invention is particularly advantageous for AR style firearms (e.g., AR-15 and M-16 rifles). Unfortunately, the location of the charging handle of the AR family of rifles is poorly suited for allowing an operator to apply a large amount of rearward force to the charging handle. Unlike charging handles which protrude from the sides of the rifles, the charging handle on AR style firearms is relatively small and centered above and in close proximity to the buttstock. Side-projecting charging handles can, in many instances, allow the operator to, in an emergency, stomp on them with their foot. However, due to the location of the charging handle, operators of AR style firearms, in many instances, are limited to using their fingers to grip the charging handle. Accordingly, the operator&#39;s finger strength is a limiting factor in the amount of force they can apply to move the charging handle of an AR style firearm rearward. 
     Clearing a stuck cartridge-case malfunction can require significant force. Accordingly, firearms with small, low-profile, or otherwise difficult to reach/grasp charging handles can be very difficult, or even impossible, to clear because the operator is unable to apply the needed force. Notably, AR style firearms are not equipped with opening-cams, unlike bolt action rifles or bolt lugs of semi/full-auto rifles that cam directly against the receiver or barrel extension. 
     The charging handles disclosed here provide a force-multiplying structure wherein even very tightly stuck cartridge cases can be cleared from firearms. The charging handles disclosed herein include a simple machine (e.g., a lever, a pulley, a wedge, and/or a screw) to provide a mechanical advantage (e.g., leverage) to force the charging handle rearward and open the bolt. For example, the charging handle can use a lever to multiply the force applied by an operator to facilitate the extraction of jammed cartridges. As used in this disclosure, the term “mechanical advantage” includes mechanisms that achieve greater force for retracting the charging handle than is manually applied to the device. 
     Advantageously, in embodiments having a lever, the lever can provide a greater surface area for an operator to contact than a traditional M-16 charging handle. 
     Additionally, charging handle designs disclosed herein can be operated ambidextrously while still disengaging a charging handle latch of the charging handle from the firearm. For example, a charging handle removal lever can be positioned on an opposing side of a charging handle base than the charging handle latch and be arranged to actuate the charging handle latch to disengage the charging handle latch from the firearm. In this way, the charging handle can be unlatched from either side of the firearm. 
     Briefly stated immediately below, and then elaborated upon further below, advantages of the present disclosure can include:
         Simplicity/ease of use   Compact/light weight   Configurable into/from a stowable configuration   Drop-in compatible with existing rifles   Does not interfere with normal operation of the rifle   Provides ambidextrous operation of the charging handle   Provides mechanical advantage for extracting a stuck cartridge-case       

     The charging handles disclosed here can be simple, and in many instances include only a few parts. In fact, in its simplest form, the charging handle may consist of two pieces. 
     The charging handle is compact and light weight. The charging handle may only add about one ounce of weight. Advantageously, charging handles disclosed herein can be configured into a stowed configuration that reduces the overall size of the charging handle when not in use. 
     The charging handles disclosed herein are easy to use. Levers of charging handles disclosed herein can be easily deployed, and stowed. Further, operation of a mechanical advantage separator of the present disclosure may operate the charging handle latch so as to disengage the charging handle latch from a slot in a receiver of the firearm. 
     The charging handles disclosed herein are suitable as a drop-in system. The charging handle can be employed in existing rifle platforms without any other modification to the rifle. 
     The charging handles disclosed herein do not interfere with the normal operation of the rifle. When the lever is stowed, the charging handle base and the charging handle latch function in exactly the same way as a standard charging handle and charging handle latch. When deployed, the lever does not prevent the operator from using the charging handle in the usual manner. Nor do the charging handles disclosed herein interfere with the use of the forward-assist. 
     Where the terms “comprise”, “comprises”, “comprised” or “comprising” are used in this specification (including the claims) they are to be interpreted as specifying the presence of the stated features, integers, steps or components, but not precluding the presence of one or more other features, integers, steps or components, or group thereof. 
     The present disclosure provides a charging handle for a firearm comprising: a charging handle base having a first end and a second end; the first end arranged for positioning within a housing of the firearm; the second end having a charging handle latch pivotably attached thereto, the charging handle latch arranged to engage the firearm to retain the second end in fixed position relative to the housing; and a rearward-assist member arranged to provide a mechanical advantage upon application of a force to move the second end of the charging handle base away from the housing when the charging handle latch is disengaged from the firearm. The rearward-assist member can be a simple machine. The simple machine can be a lever. 
     The present disclosure provides a charging handle for a firearm comprising: a charging handle base having a first end and a second end; the first end arranged for positioning within the firearm; the second end having a charging handle latch pivotably attached thereto, the charging handle latch arranged to engage another part of the firearm to retain the second end in position; and a pivoting charging handle removal lever coupled to the charging handle base, the pivoting charging handle removal lever having three separate locations to achieve a mechanical advantage: (a) a first location which engages the charging handle base or the charging handle latch, (b) a second location which engages a different part of the firearm than the charging handle base or the charging handle latch, and (c) a third location exposed for application of manual force and positioned to achieve a mechanical advantage for releasing the charging handle when stuck in the firearm. 
     The first location can be positioned in an area between the second location and the third location. The second location can be positioned in an area between the first location and the third location. 
     The lever can disengage the charging handle latch from the firearm when actuated. For example, the lever can include a cam-lug that rotates the charging handle latch away from the charging handle base and/or the receiver during rotation of the pivoting charging handle removal lever. 
     The lever can include a handle portion extending from the first location to the third location and a load portion extending from the first location to the second location and the handle portion can be selectively pivotable relative to the load portion so as to configure the pivoting charging handle removal lever from stored configuration to a deployed configuration. For example, the handle portion can be coupled to the load portion (e.g., a cam) by a spline shaft having splines and the handle portion and load portion can each have spline openings having one or more teeth and gaps sized to engage the spline shaft. The spline shaft, the handle portion, and the load portion can be arranged such that the spline shaft rotationally couples the handle portion and the load portion in one or two or more configurations. The spline shaft can have a first circumferential portion that, when positioned within the spline opening of the handle portion, rotationally locks the spline shaft relative to the handle portion and the spline shaft can have a second circumferential portion that, when positioned within the spline opening of the handle portion, allows at least 50 degrees of rotation of the handle portion relative to the spline shaft. 
     The charging handles herein can be for an AR style firearm. The first end of the charging handle base can define an opening arranged to receive a portion of a bolt carrier group of the firearm. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a firearm with a charging handle in a forward position. 
         FIGS. 2 and 3  are perspective views of the firearm of  FIG. 1  with the charging handle in a rearward position. 
         FIG. 4A  is a top view of an M16 type charging handle. 
         FIG. 4B  is a right side view of the charging handle of  FIG. 4A . 
         FIG. 4C  is a left side view of the charging handle of  FIG. 4A . 
         FIG. 4D  is an end view of the charging handle of  FIG. 4A . 
         FIG. 5A  is a top view of an M16 type upper receiver. 
         FIG. 5B  is a right side view of the upper receiver of  FIG. 5A . 
         FIG. 5C  is an end view of the upper receiver of  FIG. 5A . 
         FIG. 6A  is a partial cutaway top view of the charging handle of  FIG. 4A  inserted in the forward position in the upper receiver of  FIG. 5A . 
         FIG. 6B  is a side view of the assembly of  FIG. 6A . 
         FIG. 6C  is an end view of the assembly of  FIG. 6A . 
         FIG. 7  is a top view of a novel charging handle in a forward position in an upper receiver. 
         FIG. 8  is an exploded view of a charging handle of the present disclosure. 
         FIG. 9  is a top view of the charging handle of  FIG. 8 . 
         FIG. 10  is a top view of the charging handle of  FIG. 9  in a forward position in an upper receiver. 
         FIG. 11  is a top view close-up of the end of the assembly of  FIG. 10 . 
         FIGS. 12, 13, 14, 15, and 16  illustrate operation of the charging handle of  FIG. 10 . 
         FIG. 17  is a perspective view of a charging handle in a stowed configuration with a spline shaft in an upper position. 
         FIG. 18  is a perspective view of the charging handle of  FIG. 17  with the spline shaft in a lower position. 
         FIG. 19  is a perspective view of the charging handle of  FIG. 18  in a deployed configuration. 
         FIG. 20  is a perspective view of the charging handle of  FIG. 19  with the spline shaft in an upper position. 
         FIG. 21  is a top view of the charging handle of  FIG. 17 . 
         FIG. 22  is a perspective view of the charging handle of  FIG. 17 . 
         FIG. 23  is a top view of the charging handle of  FIG. 20 . 
         FIG. 24  is a perspective view of the charging handle of  FIG. 20 . 
         FIG. 25  is a top view during operation of the charging handle of  FIG. 20 . 
         FIGS. 26, 27, 28, and 29  illustrate top views of a charging handle configurable from a deployed configuration to a stowed configuration. 
         FIG. 30  is a top view of a load portion and a spline shaft assembled together. 
         FIG. 31  is a top view of the load portion and spline shaft of  FIG. 30  assembled with a handle portion in a deployed configuration. 
         FIG. 32  is a top view of the assembly of  FIG. 31  in a stowed configuration. 
         FIG. 33A  is a top view of a charging handle base. 
         FIG. 33B  is a left side view of the charging handle base of  FIG. 33A . 
         FIG. 33C  is an end view of the charging handle base of  FIG. 33A . 
         FIG. 33D  is a right side view of the charging handle base of  FIG. 33A . 
         FIG. 33E  is a bottom view of the charging handle base of  FIG. 33A . 
         FIG. 34A  is a top view of a charging handle base with the latch-spring pocket and latch-slot shown in phantom. 
         FIG. 34B  is an end view of the charging handle base of  FIG. 34A . 
         FIGS. 34C and 34D  are side views of the charging handle base of  FIG. 34A . 
         FIG. 34E  is a bottom view of the charging handle base of  FIG. 34A . 
         FIG. 35  is an end view of a charging handle base. 
         FIG. 36  is a cross-sectional view along line  36 - 36  of  FIG. 35 . 
         FIG. 37A  is a top view of a handle portion of a lever. 
         FIG. 37B  is a side view of the handle portion of  FIG. 37A . 
         FIG. 37C  is an end view of the handle portion of  FIG. 37A . 
         FIG. 37D  is a bottom view of the handle portion of  FIG. 37A . 
         FIG. 38  is a cross-sectional view along line  38 - 38  of  FIG. 37B . 
         FIG. 39  is a cross-sectional view along line  39 - 39  of  FIG. 37B . 
         FIG. 40  is a close-up of the handle spline hole of  FIG. 37D . 
         FIG. 41A  is a top view of a load portion (e.g., a cam) of a lever. 
         FIG. 41B  is a back side view of the load portion of  FIG. 41A . 
         FIG. 41C  is an end view of the load portion of  FIG. 41A . 
         FIG. 41D  is a front side view of the load portion of  FIG. 41A . 
         FIG. 41E  is a bottom view of the load portion of  FIG. 41A . 
         FIG. 42A  is a top view of a spline shaft. 
         FIG. 42B  is a side view of the spline shaft of  FIG. 42A . 
         FIG. 42C  is a bottom view of the spline shaft of  FIG. 42A . 
         FIG. 43  is a cross-sectional view along line  43 - 43  of  FIG. 42B . 
         FIG. 44  is a cross-sectional view along line  44 - 44  of  FIG. 42A . 
         FIG. 45A  is a top view of a charging handle latch. 
         FIG. 45B  is an end view of the charging handle latch of  FIG. 45A . 
         FIG. 45C  is a side view of the charging handle latch of  FIG. 45A . 
         FIG. 46A  is a top view of a spline-spring guide. 
         FIG. 46B  is a side view of the spline-spring guide of  FIG. 46A . 
         FIG. 47A  is a top view of a charging handle, load portion and spline shaft assembled together, with the load portion rotated into its rearward most position. 
         FIG. 47B  is a side view of the assembled charging handle, load portion and spline shaft of  FIG. 47A . 
         FIG. 47C  is an end view of the assembled charging handle, load portion and spline shaft of  FIG. 47A . 
         FIG. 48A  is top view of a charging handle, load portion and spline shaft assembled together, with the load portion rotated into its forward most position. 
         FIG. 48B  is a side view of the assembled charging handle, load portion and spline shaft of  FIG. 48A . 
         FIG. 48C  is an end view of the assembled charging handle, load portion and spline shaft of  FIG. 48A . 
         FIG. 49A  is a top view of a charging handle, load portion, spline shaft and handle portion assembled together and shown in the stowed position. 
         FIG. 49B  is an end view of the assembled charging handle, load portion, spline shaft and handle portion of  FIG. 49A . 
         FIG. 49C  is a bottom view of the assembled charging handle, load portion, spline shaft and handle portion of  FIG. 49A . 
         FIG. 50  is a close-up view of the spline shaft area of  FIG. 49C . 
         FIG. 51  is a partial cross-sectional side view of the assembly of  FIG. 49A . 
         FIG. 52  is a partial cross-sectional view of the assembly of  FIG. 49A  with the spline shaft in an upper position and spline lands of the spline shaft engaged with the spline teeth of the handle portion. 
         FIG. 53  is a partial cross-sectional view of the assembly of  FIG. 49A  with the spline shaft in a lower position and spline lands of the spline shaft not engaged with the spline teeth of the handle portion. 
         FIG. 54  is a top view of a charging handle with spline lands of a spline shaft in engagement with the spline teeth of the handle portion and the handle portion in the deployed position. 
         FIG. 55  is a partial cross-sectional side view of the spline shaft of  FIG. 54 . 
         FIG. 56  is a top view illustrating a cam-lug passage of a charging handle base, a cam-lug, and an interface prong limiting counterclockwise rotation of the lever portions. 
         FIG. 57A  is a top view of the load portion, handle portion, and interface prong of  FIG. 56 . 
         FIG. 57B  is a side view of the load portion, handle portion, and interface prong of  FIG. 56 . 
         FIG. 58  illustrates a configuration resisted by the structure of  FIGS. 56, 57A, and 57B . 
         FIG. 59  is a top, partial sectional view of a charging handle-latch assembled into the charging handle. 
         FIG. 60A  is a top view of the assembly of  FIG. 59 . 
         FIG. 60B  is an end view of the assembly of  FIG. 60A . 
         FIG. 61  is a partial sectional plan view of the charging handle-latch and spring assembled into the charging handle. 
         FIG. 62A  is a partial sectional plan view of the charging handle-latch and spring assembled into the charging handle, with an outline of the load portion (e.g., cam) for reference. 
         FIG. 62B  is an end view of the assembly of  FIG. 62A . 
         FIG. 63  is a partial sectional plan view of the charging handle-latch and spring assembled into the charging handle, with the load portion partially cut-away for a clearer view of the cam-lug and latch. 
         FIG. 64  is a partial sectional plan view of the charging handle assembled into a receiver, with the latch hook engaged with the receiver notch. 
         FIG. 65  is a partial sectional plan view of the charging handle assembled into a receiver, with the latch hook actuated out of engagement from the receiver notch and with the charging handle before rearward movement of the charging handle base. 
         FIG. 66  is a partial sectional plan view of the charging handle assembled into a receiver, with the latch hook actuated out of engagement from the receiver notch and with the charging handle. 
         FIG. 67  is a partial sectional plan view of the charging handle assembled into a receiver, with the charging handle and latch hook moved rearward away from the receiver notch. 
         FIG. 68  is a partial sectional plan view of the charging handle assembled into a receiver, with the load portion having rotated fully forward, and the charging handle having moved rearward away from the receiver. 
         FIG. 69  is a partial sectional plan view of the charging handle with the cam-lug resetting. 
         FIG. 70  is a partial sectional plan view of the charging handle with the latch being actuated manually. 
         FIG. 71A  is a top view of another embodiment of a charging handle. 
         FIG. 71B  is an end view of the embodiment of  FIG. 71A . 
         FIG. 71C  is a side view of the embodiment of  FIG. 71A . 
         FIG. 72A  is a top view of another embodiment of a charging handle. 
         FIG. 72B  is an end view of the embodiment of  FIG. 72A . 
         FIG. 72C  is an exploded side view of the embodiment of  FIG. 72A . 
         FIG. 73A  is a top view of another embodiment of a lever. 
         FIG. 73B  is an end view of the lever of  FIG. 73A . 
         FIG. 73C  is a side view of the lever of  FIG. 73A . 
         FIG. 73D  is an end view of the lever of  FIG. 73A . 
         FIG. 74A  is a top view of the lever of  FIG. 73A  assembled on a charging handle base. 
         FIG. 74B  is an end view of the assembly of  FIG. 74A . 
         FIG. 74C  is a side view of the assembly of  FIG. 74A . 
         FIG. 75  is a top view of a lever actuating a charging handle latch. 
     
    
    
     DESCRIPTION OF THE SELECTED EMBODIMENTS 
     For the purpose of promoting an understanding of the principles of the present disclosure, reference will now be made to the embodiments illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the present disclosure is thereby intended. Any alterations and further modifications in the described embodiments, and any further applications of the principles of the present disclosure as described herein are contemplated as would normally occur to one skilled in the art to which the invention relates. One embodiment of the invention is shown in detail, although it will be apparent to those skilled in the relevant art that some features that are not relevant to the present invention may not be shown for the sake of clarity. 
     With respect to the specification and claims, it should be noted that the singular forms “a”, “an”, “the”, and the like include plural referents unless expressly discussed otherwise. As an illustration, references to “a device” or “the device” include one or more of such devices and equivalents thereof. It also should be noted that directional terms, such as “upper”, “lower”, “bottom”, “forward”, “rearward” and the like, are used herein solely for the convenience of the reader in order to aid in the reader&#39;s understanding of the illustrated embodiments, and it is not the intent that the use of these directional terms in any manner limit the described, illustrated, and/or claimed features to a specific direction and/or orientation. 
     The charging handle arrangements disclosed herein can be applied to any number of firearm types; however, it is envisioned the AR family of firearm (e.g., AR-15 and M16) will most readily benefit from such devices. With this in mind, the charging handles illustrated herein are described with reference to an unmodified AR-15 type upper receiver. Specifically, a flat-top AR-15 type upper receiver with a Picatinny Rail. However, this should not be considered limiting. 
     For the purposes of the Description, friction is acknowledged as a practical design factor, but is ignored (except where noted) in this document as not being required for understanding the principles of the invention. 
       FIG. 1  illustrates an AR style firearm  1  having an upper receiver  2 , a lower receiver  4 , a barrel  6 , a bolt carrier group  8 , and a charging handle  20  in a forward, latched position.  FIGS. 2 and 3  illustrate the firearm  1  with the charging handle  20  and bolt carrier group  8  of  FIG. 1  in a rearward position. The firearm includes a receiver notch  15  that receives a charging handle latch  25  when the charging handle is in the forward, latched position. When the charging handle latch  25  is engaged with the receiver notch  15 , the charging handle is retained in the forward position. 
     As shown in  FIGS. 4A-D , existing charging handles  20  include a charging handle latch  25  that resides within a latch-slot  22  of a charging handle base  24 . The charging handle  20  has a latch-retainer hole  23  and a latch-spring pocket  27  (the spring is not shown). Charging handle-latch  25  pivots about a retaining pin (not shown) fitted into latch-retainer hole  23  so that the charging handle-latch can be rotated to selectively engage and disengage from receiver notch  15 . 
     As shown in  FIGS. 5A-C , an upper receiver  10  can be equipped with a receiver-rail  35 . Receiver-rail  35  is depicted here in the 1913 Picatinny rail configuration; however, other configurations are envisioned, such as other rail systems and/or an integral carry handle, as are other types/makes/models of firearms. A rearward portion of the upper receiver (e.g., end of receiver-rail  35 ) has a rearward-facing surface  30 . As illustrated in  FIG. 5A , the rearward-facing surface can be a rounded, rearward-facing surface of receiver-rail  35 . 
       FIGS. 6A-6C  illustrate charging handle  20  received in upper receiver  10  in a forward, latched position. As can be seen, charging handle  20  fits inside receiver  10 , beneath receiver-rail  35 , with latch  25  engaged in receiver notch  15 . 
     In contrast to the charging handles shown in the previously discussed figures, novel charging handles disclosed herein advantageously provide a mechanical advantage (e.g., leverage) to force the charging handle rearward. Turning now to specific embodiments of the present disclosure, the charging handle can include a lever arranged to contact a portion of the firearm to force the charging handle rearward.  FIG. 7  illustrates an embodiment wherein the charging handle includes a lever  56  pivotably coupled to the novel charging handle base  40  through a shaft  70 . 
     In  FIG. 7 , the lever  56  functions as a first-class lever relative to the charging handle base  40 . When a force is exerted on a handle portion  50  (e.g., a handle) of lever  56 , a load portion  60  (e.g., a cam) of lever  56  applies a force to rearward-facing surface  30  (of  FIGS. 5A-5B ) of the firearm to separate the charging handle from the firearm. 
       FIG. 8  illustrates an exploded view of an embodiment of a charging handle  38  having lever comprising a handle portion  50  that is selectively pivotable relative to a load portion  60 . In  FIG. 8 , the charging handle base  40  defines a spline pivot hole  45  that rotatably and reciprocatingly receives a spline shaft  70 . Similarly, load portion  60  defines a cam spline hole  65  and handle portion  50  defines a handle spline hole  55 . Each of the cam spline hole and the handle spline hole are arranged to reciprocatingly receive the spline shaft. 
     Spline shaft  70  has splines extending longitudinally there along. For example, spline shaft  70  can have a land  75 , which can be wider than the other spline-lands. As will be appreciated by one skilled in the art, the size/shape/number/configuration/orientation/etc. of the spline lands are not limited to the configuration shown. For example, a spline shaft with a single land is envisioned. 
     Still referring to  FIG. 8 , where load portion  60  with cam spline hole  65  can be seen, cam spline hole  65  is configured to accept spline shaft  70 . Cam spline hole  65  has cam spline gap  61 . Cam spline gap  61  is configured to accept land  75  of spline shaft  70 . Land  75 , being too large to do otherwise, will only assemble with cam spline gap  61 . Advantageously, alignment provided by spline land  75  and cam spline gap  61  can aid in the proper alignment of the components during assembly of the mechanism. 
     Unlike spline shaft  70  and cam spline hole  65  that each have only one larger spline or spline gap in their spline configuration, handle spline hole  55  of handle portion  50  can have multiple. A first lever spline gap  51  and a second lever spline gap  52  of handle spline hole  55  will both accept land  75  of spline shaft  70 . For example, handle spline hole  55  can be configured to accept spline shaft  70 , with land  75 , in two orientations. These two orientations correspond to handle portion  50  being in either a stowed position or a deployed position. In some instances, handle spline hole  55  may only accept spline shaft  70  in the two orientations described above. For example, land  75 , of spline shaft  70  may be configured to prevent spline shaft  70  from engaging with spline hole  55  in any orientation other than the stowed position or the deployed position. 
     Referring now to  FIG. 9 , which is a plan view of the basic components of the charging handle  38  (of  FIG. 8 ) assembled together. In this view spline pivot hole  45 , in novel charging handle base  40 , is no longer visible. Spline shaft  70  is assembled into spline pivot hole  45 . Spline shaft  70  is free to rotate within spline pivot hole  45 . Spline shaft  70  extends down through spline pivot hole  45 . Spline shaft  70  also extends up through cam spline hole  65  of load portion  60  and through handle spline hole  55  of handle portion  50 . The spline lands of spline shaft  70  are engaged with the spline teeth of cam spline hole  65  of load portion  60 . The spline lands of spline shaft  70  are also engaged with the spline teeth of handle spline hole  55  of handle portion  50 . Engaged in this way, spline shaft  70 , load portion  60  and handle portion  50  will all rotate together. In this figure, handle portion  50  is depicted in the deployed position, with land  75 , of spline shaft  70 , engaged with first lever spline gap  51 . 
       FIG. 10  is a plan view of the basic components of the charging handle  38  assembled together and shown in the fully forward position within receiver  10 . In this view the proximity of load portion  60  to rearward-facing surface  30  can be seen. 
       FIG. 11  is a close-up view of the charging handle as depicted in  FIG. 10 , with some details of receiver  10  being omitted for clarity. In this view, handle portion  50  is shown in the fully deployed position, with angle “A” at its most acute angle. Also, the engagement of the spline lands of spline shaft  70  with the spline teeth of handle spline hole  55  can be more clearly seen. 
     In  FIG. 11 , load portion  60  is not yet in contact with rearward-facing surface  30 , having cam-gap  80  between them. Cam-gap  80  is not necessary for the functioning of the camming components of the charging handle. However, cam-gap  80  can aid by providing tolerance for proper operation and functioning of the handle-latch. 
     In  FIG. 12 , angle “A” has increased slightly, cam-gap  80  is closed, and load portion  60  is now in contact with rearward-facing surface  30  at contact point  85 . This may be the configuration upon application of a rearward force to handle portion  50 . Handle portion  50 , being engaged to spline shaft  70  via handle spline hole  55 , has transmitted the rearward force to spline shaft  70 . Spline shaft  70  being pivotally mounted within spline pivot hole  45  (of  FIG. 8 ) has converted the rearward force into a rotational force. Spline shaft  70 , also being engaged to load portion  60  via cam spline hole  65  (of  FIG. 8 ), has, in turn, also transmitted the force to load portion  60 , causing load portion  60  to rotate slightly. 
       FIGS. 13-16  illustrate a progression of charging handle displacement when the charging handle is separating from the firearm. In these figures, rearward-facing surface  30  is shown as being stationary while novel charging handle base  40  is considered as being movable. 
       FIGS. 13-15  depict the force-multiplier aspect of the charging handle as force is applied to handle portion  50 . For example, as a rearward force is applied to handle portion  50 , handle portion  50  communicates that rearward force to spline shaft  70 . Spline shaft  70  being pivotally mounted in spline pivot hole  45  (not shown), of novel charging handle base  40 , converts the rearward force into a clockwise rotational force. Because load portion  60  is also connected/splined to spline shaft  70 , load portion  60  also receives the clockwise rotational force. Load portion  60 , being rotated by the clockwise rotational force comes into contact with rearward-facing surface  30 , at contact point  85 . Contact point  85  of rearward-facing surface  30  exerts a longitudinal/rearward reaction force against load portion  60  that is applied back to spline shaft  70 . Spline shaft  70 , being mounted in spline pivot hole  45  of novel charging handle base  40 , transmits this longitudinal/rearward reaction force to novel charging handle base  40  so as to force novel charging handle base  40  in a rearward direction. 
     In  FIGS. 13-15 , it can be seen that the circumferential distance handle portion  50  rotates through angle “A” is greater than the longitudinal distance B that novel charging handle base  40  moves. This demonstrates the force applied to handle portion  50  is increased in mechanical advantage through the employment of leverage. Also, it should be noted that, under a static analysis, the rearward force applied by a user to the handle portion  50  is cumulative with the rearward force exerted on the charging handle  38  by the rearward-facing surface  30 . In other words, the rearward force applied to handle portion  50  is not just functioning the charging handle mechanism. Rather, the initial force is, itself, helping to push the charging handle rearward. 
     Referring again to  FIG. 13 , which depicts the charging handle&#39;s components in the same orientations/positions as  FIG. 12 , a rearward force is being applied to handle portion  50 , and load portion  60  has rotated into contact with rearward-facing surface  30 . Angle “A” has increased slightly from its starting location (as shown in  FIG. 11 ), but distance-B is still at its minimum value. 
     In  FIG. 14 , the rearward force being applied to handle portion  50  has caused handle portion  50 , spline shaft  70  and load portion  60  to rotate and partially extract the charging handle  38  from the firearm. As can be seen relative to  FIG. 13 , angle “A” has increased and distance B has now also increased. 
     Referring now to  FIG. 15 , the rearward force applied to handle portion  50  has caused handle portion  50 , spline shaft  70  and load portion  60  to rotate further. Relative to  FIG. 14 , angle “A” is shown as having increased and distance B has once again increased. 
     The profile of load portion  60  (e.g., the cam) of lever  56  can be configured for specific contact between load portion  60  and rearward-facing surface  30 . For example, load portion  60  may have a cam profile. In some instances, the cam profile is curved so that the point of contact with rearward-facing surface is approximately orthogonal (±20 degrees) to the longitudinal axis of the charging handle base throughout the movement of the pivot axis of the load portion (e.g., the spline shaft) away from the rearward-facing surface. For example, the cam profile may resemble a Fibonacci spiral. Advantageously, such arrangements can reduce the total force required to be applied to the charging handle and upper receiver to achieve a desired force in the rearward direction. 
     The location of contact point  85  may move throughout the charging handle&#39;s function. For example, as shown in  FIGS. 13-15 , the location of contact point  85  varies during operation of the charging handle. Such an arrangement can be achieved by configuring the shape of load portion  60 . For example, load portion  60  can have an arcuate surface so that as the load portion rotates around spline shaft  70 , which moves away from rearward-facing surface  30 , the load portion slides across a portion of rearward-facing surface  30 . 
     It is envisioned that load portion  60  may have a cam profile that would result in load portion  60  contacting rearward-facing surface  30  at the same point throughout charging handle operation. For example, the cam profile can be arranged so that the point of contact with the rearward-facing surface is vertically aligned with a central longitudinal axis of the charging handle substantially throughout the movement of the charging handle rearward. Advantageously, such arrangements can reduce the torque experienced by the charging handle when the charging handle is applying a particular force to the rearward facing surface. 
     Conversely, it is also envisioned that load portion  60  may have a cam profile that would result in load portion  60  continually rolling over rearward-facing surface  30  in a 1:1 ratio. In this way all sliding friction would be eliminated. This would have the advantage of spreading out any damage suffered by the surfaces during operation, while greatly reducing friction. 
     Additionally or alternatively, some form of roller-bearing could be employed between load portion  60  and rearward-facing surface  30 . Also, low friction materials (such as Nylon, Teflon, etc.) could be employed to further reduce friction. 
     In  FIG. 16 , the charging handle has completed the improved mechanical-advantage phase, and now novel charging handle base  40  continues rearward in the conventional fashion, completing the bolt opening process. 
       FIGS. 17-20  illustrate a process of configuring handle portion  50  from a stowed configuration to a deployed configuration that is usable for leveraging. In  FIG. 17 , handle portion  50  extends along a rearward end of charging handle base  40 . In  FIG. 18 , spline shaft  70  is depressed so as to disengage the splines of spline shaft  70  from spline teeth and gaps of handle spline hole  55 . When spline shaft  70  is disengaged from the spline teeth and the gaps of th\e handle spline hole  55 , handle portion  50  may be rotated to the deployed configuration, as shown in  FIG. 19 . When in the deployed configuration, spline shaft  70  can be allowed to return to an upper position, such as under the force of spring bias, to engage one or more splines of spline shaft  70  with the spline teeth and the gaps of handle spline hole  55 , as shown in  FIG. 20 . When the one or more splines of the spline shaft  70  are engaged with the spline teeth and gaps of handle spline hole  55  and cam spline hole  65 , actuation of handle portion  50  rotates spline shaft  70  which, in turn, rotates load portion  60 . To configure the charging handle from the deployed configuration to the stowed configuration, the process can be reversed (i.e., depressing spline shaft  70  in the configuration illustrated in  FIG. 20 , rotating the lever to the stowed configuration, and allowing spline shaft  70  to return to the upper position). 
       FIGS. 21 and 22  illustrate additional views of a charging handle with handle portion  50  in a stowed configuration.  FIGS. 23 and 24  illustrate additional view of a charging handle with handle portion  50  in a deployed configuration.  FIGS. 22 and 24  also illustrate other features of charging handle  38 , such as an opening  48  arranged to receive a gas key and/or a piston associated with a bolt carrier group of the firearm. 
       FIG. 25  illustrates that lever  56  can actuate charging handle latch  25 , in at least some embodiments, in response to actuation of handle portion  50 . In comparison to  FIG. 23 , handle portion  50 , load portion  60 , and spline shaft  70  have rotated relative to the position shown in  FIG. 25 . As can be seen, charging handle latch  25  has pivoted away from charging handle base  40  in  FIG. 25 . 
     A more detailed description of how the charging handle is configurable from the stowed configuration to the deployed configuration, and vice versa, is described in the following figures. Additionally, further description as to how the lever  56  actuates the charging handle latch is further described below. 
     Referring now to  FIGS. 26-32 , the process of stowing handle portion  50  is shown. In these figures, it is assumed that load portion  60  is being held stationary. In  FIGS. 26-32 , the spline teeth of load portion  60  have been removed for clarity. For example,  FIG. 30  shows the spline teeth of cam spline hole  65 . This has been done to more clearly show the relationship of the spline lands of spline shaft  70  to the spline teeth of handle spline hole  55 , of handle portion  50 . Additionally, in  FIGS. 30-32  novel charging handle base  40  has been removed for clarity so the details discussed in  FIG. 26-29  can be more clearly seen.  FIG. 31  is a simplified view of  FIG. 26 , and  FIG. 32  is a simplified view of  FIG. 29 . 
     In  FIGS. 26 and 31 , handle portion  50  is shown in the fully deployed position. In these figures, spline shaft  70  extends down into spline pivot hole  45  (not shown) of novel charging handle base  40 . Spline shaft  70  extends up through cam spline hole  65  of load portion  60 . Spline shaft  70  also extends up into handle spline hole  55  of handle portion  50 . The spline lands of spline shaft  70  are engaged with the spline teeth of cam spline hole  65  and handle spline hole  55 . Spline shaft  70  is free to reciprocate within spline pivot hole  45  and cam spline hole  65  and handle spline hole  55 . 
       FIG. 28  illustrates handle portion  50  in an intermediate position between deployed and stowed. Before handle portion  50  is rotated relative to load portion  60 , spline shaft  70  is disengaged from handle portion  50 . For example, spline shaft  70  being free to reciprocate can be depressed sufficiently to drop below the level of handle portion  50 . In other words, spline shaft  70  has been pushed down under handle portion  50  to disengage spline shaft  70  from handle portion  50 . Disengaging spline shaft  70  from handle portion  50  allows handle portion  50  to freely rotate relative to spline shaft  70  and, therefore, load portion  60  and novel charging handle base  40 . 
     Once handle portion  50  has begun to rotate toward the stowed position, or vice versa, spline shaft  70  is prevented from re-engaging with handle portion  50  until handle portion  50  is in the fully stowed (or fully deployed) position.  FIG. 28  shows more clearly how land  75  of spline shaft  70  interferes with the spline teeth of handle spline hole  55 . As can be seen, land  75  of spline shaft  70  is too wide to engage with any other spline gap of handle spline hole  55  except first lever spline gap  51  and second lever spline gap  52 . For example, spline shaft  70  with land  75  can be arranged to only re-engage with handle spline hole  55  once handle portion  50  is rotated sufficiently to either bring first lever spline gap  51  or second lever spline gap  52  back into alignment with land  75 . 
     Embodiments using a symmetrical spline are envisioned; however, such embodiments may require an operator to manually hold spline shaft  70  down until handle portion  50  is fully rotated into the desired position. 
     In  FIGS. 29 and 32 , handle portion  50  has rotated to the fully stowed position. In this position, spline shaft  70  with land  75  can now re-engage with handle spline hole  55  of handle portion  50  because second lever spline gap  52  is in alignment with land  75 . This can be more clearly seen in  FIG. 32 . 
     The engagement of spline shaft  70  to load portion  60  can be clearly seen in  FIG. 30  (handle portion  50  has been removed for clarity). This view clearly shows land  75  of spline shaft  70  is too wide to be positioned in any spline gap in cam spline hole  65 , other than cam spline gap  61 . It should be noted that spline shaft  70  may not disengage from load portion  60  at any point during charging handle operation. For example, unlike handle portion  50  which selectively disengages from spline shaft  70  when handle portion  50  is being either deployed or stowed, load portion  60  may maintain engagement with spline shaft  70  throughout charging handle operation, regardless of the position of handle portion  50 . However, even if the spline lands of spline shaft  70  never disengage (rotationally) from the spline teeth of load portion  60 , spline shaft  70  is free to reciprocate within cam spline hole  65  of load portion  60 . 
     As stated before,  FIG. 31  is a simplified view of  FIG. 26 , where the details of spline shaft  70  and handle spline hole  55  can be more clearly seen (the teeth of cam spline hole  65  are not shown). In this view, handle portion  50  is depicted in the fully deployed position with land  75 , of spline shaft  70 , engaged with first lever spline gap  51 . In this view it can also be seen that second lever spline gap  52  is configured to allow a different spline land(s) of spline shaft  70  to engage with second lever spline gap  52 , albeit without filling the groove between the lands. 
     As stated before,  FIG. 32  is a simplified view of  FIG. 29 , where the details of spline shaft  70  and handle spline hole  55  can be more clearly seen (the teeth of cam spline hole  65  are not shown). In this view, handle portion  50  is depicted in the fully stowed position with land  75 , of spline shaft  70 , now engaged with second lever spline gap  52 . In this view it can also be seen that first lever spline gap  51  is also configured to allow a different spline land(s) of spline shaft  70  to engage with first lever spline gap  51 , albeit without filling the groove between the lands. 
     While only select embodiments have been illustrated and described, other size/shape/number/configuration/orientation/etc. of the spline lands/teeth are envisioned where spline shaft  70  is prevented from engaging with handle spline hole  55 , in handle portion  50 , unless/until handle portion  50  is in the desired operational position(s). Additionally, while in the above-discussed figures handle portion  50  is shown as having only two extreme (fully deployed/stowed) positions, it is contemplated to have additional spline gaps that would allow handle portion  50  to be rotationally fixed, relative to the spline shaft, in other positions. 
     Additionally, spline land  75  and first lever spline gap  51  and second lever spline gap  52  could also be eliminated. For example, a symmetrical spline profile could be employed. This would allow the position(s) of handle portion  50  to be selected/customized by the operator. In this scenario the available positions of handle portion  50  would only be limited by the number of spline lands/teeth. However, in such an embodiment the operator may be required to manually hold spline shaft  70  down while handle portion  50  was being rotated into the desired position. 
       FIGS. 33A-36  illustrate views of a charging handle base  40  for any of the charging handles  38  disclosed herein.  FIGS. 33A-33E  are shown without any hidden lines. That is, all the lines shown in  FIGS. 33A-33E  are ones that would be seen from the outside of the part. Whereas  34 A- 34 E and  35  contain selected hidden lines to better show the relationship of the various features of novel charging handle base  40 . 
       FIGS. 33A-33E  illustrate a novel charging handle base  40  having a spline pivot hole  45 , a latch-slot  42 , a latch-retainer hole  43 , and a cam-lug passage  46 . Latch-slot  42  and latch-retainer hole  43  serve essentially the same functions as the corresponding features in charging handle  20 . That is, latch-slot  42  serves essentially the same function as latch-slot  22 , and latch-retainer hole  43  serves essentially the same function as latch-retainer hole  23 . 
     In this particular example, cam-lug passage  46  is configured in the shape of an arc, centered on spline pivot hole  45 . Cam-lug passage  46  communicates between the upper surface of novel charging handle base  40  into latch-slot  42 . Cam-lug passage  46  allows load portion  60  to interact with latch  90 . While in the illustrated example cam-lug passage  46  is configured in the shape of an arc whose radius originates from the center of spline pivot hole  45 , those skilled in the art will appreciate the shape/origin of cam-lug passage  46  can have other arrangements. Optionally, cam-lug passage  46  may extend through the thickness of charging handle base  40 . 
       FIGS. 34A-34E  illustrate a latch-spring pocket  41 . Latch-spring pocket  41  is arranged to retain a latch spring that biases the latch into a position to engage receiver notch  15  of the firearm. In comparison to latch-spring pocket  27  of existing charging handles, latch-spring pocket  41  has been rotated relative to charging handle base  40 . 
       FIGS. 35 and 36  illustrate the interior of latch-slot  42 . As can be seen, latch-spring pocket  41  intersects latch-slot  42 . Also, as stated before, cam-lug passage  46  can be seen intersecting latch-slot  42 . 
       FIGS. 37A-40  illustrate multiple views of a handle portion  50 . Handle portion  50  can have a lever back-strap  53  and lower lever-arm  58 . Advantageously, lever back-strap  53  and lower lever-arm  58  greatly increase the strength of handle portion  50 . Also, lever back-strap  53  and lower lever-arm  58  provide structure to maintain handle portion  50  in both assembly to, and alignment with, charging handle base  40 . 
     Handle portion  50  may include a lower-arm well  59 . Lower-arm well  59  can contains a second set of spline teeth in large diameter spline hole  57 . Advantageously, the addition of a second set of splines can increase the strength of handle portion  50 . For clarity, large diameter spline hole  57  is shown as having a similar spline tooth configuration as handle spline hole  55 ; however, large diameter spline hole  57  may have a symmetrical spline tooth arrangement for greater engagement area and/or strength. For example, large diameter spline hole  57  may have all of its teeth (i.e. not have the spline gaps that handle spline hole  55  has). 
     Still referring to  FIGS. 37A-40 , where interface prong  54  of lever back-strap  53  can be seen, interface prong  54  will interact with load portion  60 . Interface prong  54  helps to align the spline teeth of load portion  60  and spline shaft  70  to handle portion  50  when handle portion  50  is fully deployed. 
     Referring now to  FIGS. 41A-41E , load portion  60  can include a cam lug  66 . Cam lug  66  is arranged to extend through cam-lug passage  46 , of novel charging handle base  40 , to interact with latch  90 . Cam lug  66  is depicted as being cylindrical; however, other shapes/configurations are envisioned. 
     Referring now to  FIGS. 42A-42C , spline shaft  70  can have a large diameter spline  71 , a spline-button  72 , a spline-spring pocket  73  and a cylindrical portion  74 . Large diameter spline  71  is configured to selectively engage with large diameter spline hole  57  of handle portion  50 . Spline-button  72  is configured to protrude above handle portion  50  to allow the operator to actuate spline shaft  70 . Spline-button  72  is configured to fit within the inner-diameter of handle spline hole  55 . Spline-spring pocket  73  accepts/retains spline-spring  78  (not shown) that biases spline shaft  70  in an upward position. Cylindrical portion  74  fits within spline pivot hole  45 , of charging handle base  40 . Advantageously, the interruption of the spline lands at cylindrical portion  74  can provide a continuous surface for the purposes of pivoting within spline pivot hole  45  of charging handle base  40  and, when actuated, large diameter spline  71  of handle portion  50 . 
     Referring now to  FIGS. 45A-45C , charging handle latch  90  can be arranged for actuation by cam lug  66  of load portion  60 . For example, cam lug  66 , of load portion  60 , can extend into cam-lug track  92  and interacts with a first latch cam  93 , a cam dwell  96  and a second latch-cam  94  to selectively actuate latch  90 . 
     Referring now to  FIGS. 46A-46B , a spline-spring guide  79  may be included to maintain proper control of spline-spring  78  (not shown), and/or to prevent unwanted dirt/debris from entering lower-arm well  59  of handle portion  50 . 
       FIGS. 47A-48C  illustrate load portion  60  and spline shaft  70  assembled together, with spline shaft  70  assembled into spline pivot hole  45  of charging handle base  40 . As can be seen, cam lug  66  is in contact with the rearward end/surface of cam-lug passage  46  when load portion  60  is rotated counterclockwise as far as possible. Contact of cam lug  66  with the rearward end of cam-lug passage  46  of charging handle base  40  can limit the counterclockwise rotation of load portion  60 . 
     Referring now  FIGS. 48A-48C , which again illustrates load portion  60  and spline shaft  70  assembled together with spline shaft  70  assembled into spline pivot hole  45  of charging handle base  40 , cam lug  66  is in contact with the forward end/surface of cam-lug passage  46 . That is, load portion  60  is rotated clockwise as far as possible. 
     While cam lug  66  contacting the ends of cam-lug passage  46  has been described here as limiting the rotational extent of load portion  60 , other means are envisioned. For example, other materials and/or surfaces could be added to charging handle base  40  to contact load portion  60  and limit the extent of rotation thereof in at least one direction. 
     In  FIGS. 49A-51 , load portion  60  and spline shaft  70  are assembled together with spline shaft  70  assembled into spline pivot hole  45  of charging handle base  40  and load portion  60  rotated counterclockwise until cam lug  66  contacts the rearward end of cam-lug passage  46 . As can be seen in these figures, handle portion  50  with lower lever-arm  58  acting in conjunction with spline shaft  70  can hold the charging handle in assembly. For example, handle portion  50  with lower lever-arm  58  can encircle charging handle base  40  and load portion  60  to resist them from separating vertically. Spline shaft  70  can pin charging handle base  40 , load portion  60 , and handle portion  50  together, resisting them from separating laterally. 
     The charging handle can be assembled in the following order, starting with charging handle base  40 : Load portion  60  positioned on handle base  40  with cam lug  66  positioned in cam-lug passage  46 . Handle portion  50  is position on load portion  60  and handle base  40  with handle spline hole  55  aligned above cam spline hole  65  of load portion  60  and large diameter spline hole  57  of lower lever-arm  58  positioned below spline pivot hole  45  of handle base  40 . Spline shaft  70  is inserted up through large diameter spline hole  57 , spline pivot hole  45 , cam spline hole  65 , and handle spline hole  55 . Spline shaft  70  can have a large diameter spline  71  that is larger than spline pivot hole  45  so as to prohibit the large diameter spline  71  from passing through the spline pivot hole  45 . Advantageously, spline shaft  70  can maintain the assembly in the assembled configuration as long as spline shaft  70  is maintained in the spline pivot hole, cam spline hole, and handle spline hole. 
     Still referring to  FIGS. 49A-51 , where it can be seen that the spline lands of spline shaft  70  are engaged with the spline teeth of handle spline hole  55 , the spline lands of large diameter spline  71  of spline shaft  70  can be engaged with the spline teeth of large diameter spline hole  57  of handle portion  50  and/or the spline lands of spline shaft  70  can be engaged to the spline teeth of load portion  60 . When engaged to handle portion  50  and load portion  60 , spline shaft  70  can prevent the parts from rotating. That is, load portion  60  cannot rotate counterclockwise because of the engagement of cam lug  66  with cam-lug passage  46 , and handle portion  50  cannot rotate in a clockwise direction because lever back-strap  53  of handle portion  50  is in contact with charging handle base  40 . Because spline shaft  70  ties all three parts together, via the spline engagements, the three parts are held in fixed position. 
     It is envisioned that the interior of lower-arm well  59  may not contain spline teeth below large diameter spline hole  57 . Additionally or alternatively, the spline lands of spline shaft  70  may not extend down the full length of spline shaft  70 . For example, the spline lands may terminate just below load portion  60  leaving solid/cylindrical portion  74 , of spline shaft  70 , to contact charging handle base  40 , in spline pivot hole  45 . Spline-button  72  can be cylindrical and can extend well above handle portion  50 . 
     Turning now to  FIG. 52 , which illustrates spline shaft  70  in an engaged position, a spline-spring  78  can fit within spline-spring pocket  73  of spline shaft  70  and a spline-spring guide  79  can fit within spline-spring  78  and lower-arm well  59  of handle portion  50 . Spline-spring guide  79  can be configured to fit within, and support, spline-spring  78  within spline-spring pocket  73 . Additionally, spline-spring guide  79  can closely fit (radially) within lower-arm well  59  of handle portion  50 . Configured in this way, spline-spring guide  79  can support spline-spring  78  and resist dirt from entering lower-arm well  59 . The spline-spring guide  79  can be retained by spline retainer pin  105 . The spline-spring  78  urges spline shaft  70  upward. 
       FIG. 53  illustrates spline shaft  70  in a disengaged position. In the disengaged position, spline shaft  70  is lowered/depressed so that the spline lands, of spline shaft  70 , have disengaged from the spline teeth of handle portion  50 . Specifically, the spline lands of spline shaft  70  have disengaged from (e.g., dropped below) the spline teeth of handle spline hole  55 , and the spline lands of large diameter spline  71  have disengaged from (e.g., dropped below) the spline teeth of large diameter spline hole  57 . 
     Although the spline lands/teeth themselves have disengaged, the cylindrical portions of spline shaft  70  are still contacting/guiding handle portion  50 . That is, the cylindrical sides of spline-button  72  are configured to fit within, and guide upon, the internal diameter of the spline teeth of handle spline hole  55 . Also, cylindrical portion  74 , of spline shaft  70 , is configured to fit within, and guide upon, the internal diameter of the spline teeth of large diameter spline hole  57 . Guided in this way, handle portion  50  is still constrained concentrically by/with spline shaft  70 , which is itself held in spline pivot hole  45 , despite the spline lands/teeth themselves being disengaged. In other words, handle portion  50  is now free to rotate around the cylindrical portions of spline shaft  70 , into the deployed position or vice-versa. 
     As illustrated in  FIG. 53 , the spline lands of spline shaft  70  are engaged to the spline teeth of load portion  60 . Also, the downward travel of spline shaft  70  is limited by a spline retainer pin  105 . The spline retainer pin  105  is depicted here as a pin (e.g., dowel), however a large variety of other retainer options are contemplated, including but not limited to: roll/spring/taper/cotter/etc.-pins, retaining rings, spring-clips, safety-wires, etc. Also, retention options that do not require additional components could also be employed, such as: press-fitting spline-spring guide  79  into lower-arm well  59 , or swedging/forming/bending lower-arm well  59  over/shut after assembly, or gluing/welding/etc. spline-spring guide  79  into lower-arm well  59 , etc. 
     In  FIG. 54 , handle portion  50  has been rotated back into the deployed position. When handle portion  50  is rotated into the deployed position, spline shaft  70  is able to, under the influence of spline-spring  78 , reciprocate upwards so that the spline lands of spline shaft  70  engage with the spline teeth of handle portion  50 , as shown in  FIG. 55 , with land  75  of spline shaft  70  engaged with first lever spline gap  51 . In comparison, when handle portion  50  is in the retracted position, land  75  is aligned with, and can engage, second lever spline gap  52 . 
     In the deployed configuration with spline shaft  70  engaged with handle portion  50  and load portion  60 , the charging handle is ready to perform the rearward-assist camming functions described above. Notably, spline shaft  70  and load portion  60  may not rotate relative to each other when handle portion  50  is configured into the deployed configuration and/or the stowed configuration. 
       FIG. 56 , is a partial sectional plan view illustrating the interaction of interface prong  54  with interface notch  64 . Interface prong  54  limits the rotation of handle portion  50  and load portion  60  relative to one another. For example, the interface prong can limit the distance, in at least one direction, that handle portion  50  can rotate relative to load portion  60 . 
     As can be seen, while handle portion  50  is being rotated (e.g., counterclockwise) into the deployed position, interface prong  54 , of handle portion  50 , will contact interface notch  64 , of load portion  60 . In so doing, interface prong  54  may rotate load portion  60  rearward so as to align the spline lands of spline shaft  70  with the spline teeth and spline gaps of handle portion  50 . In such an arrangement, interface prong  54  may also restrict handle portion  50  from rotating beyond alignment with load portion  60  and/or spline shaft  70 . In embodiments including a cam-lug and a cam-lug passage (e.g., cam lug  66  and cam-lug passage  46 ), rotation of the load portion  60  may be limited by contact of the cam-lug with a rear surface of the cam-lug passage. Accordingly, structure for limiting rotation of both load portion  60  and handle portion  50  relative to charging handle base  40  has been disclosed. 
       FIGS. 57A and 57B  illustrate the interaction between interface prong  54  and interface notch  64 . Again, interface prong  54  is arranged to limit the distance handle portion  50  may rotate in at least one direction (e.g., counterclockwise) relative to load portion  60 . 
       FIG. 58  depicts an orientation which may occur if the charging handle does not include an interface prong. In this illustration, handle portion  50  has rotated (counterclockwise) into the fully deployed position, but load portion  60  remains in a forward (clockwise) rotational position. As can be seen, spline shaft  70 , which is engaged with load portion  60 , is misaligned with handle spline hole  55 , and therefore the spline lands of spline shaft  70  cannot engage with the spline teeth of handle portion  50 . 
       FIG. 59  depicts a partial sectional plan view of charging handle base  40  with latch  90  assembled into latch-slot  42 . A latch pivot pin  110  is assembled into latch pivot hole  95 , of latch  90  and latch-retainer hole  43 , of charging handle base  40 . Latch  90  is pivotable around latch pivot pin  110 . Latch pivot pin  110  is depicted as a roll-pin; however, other retention devices may be used. 
     In this view the orientation of latch-spring pocket  41  and latch-spring notch  98  can be clearly seen. Latch-spring pocket  41 , of charging handle base  40 , opens towards latch-spring notch  98 . Referring now to  FIGS. 60A and 60B , the relative orientation of cam-lug passage  46  to cam-lug track  92  can be seen. When latch  90  is assembled into latch-slot  42 , cam-lug track  92  is positioned beneath, and can be accessible through, cam-lug passage  46 . 
     Referring now to  FIG. 61 , a latch-spring  99  fits within latch-spring pocket  41  of charging handle base  40  and latch-spring notch  98  of latch  90 . As can be seen in this figure, latch-spring  99  urges latch  90  to rotated around latch pivot pin  110 , in a clockwise direction. In some instances, latch-spring  99  may bias latch  90  around latch pivot pin  110  until hook  91 , of latch  90 , contacts charging handle base  40 . 
       FIGS. 62A and 62B  include load portion  60  in transparent form. That is, the edges of load portion  60  are shown, but none of the other components below load portion  60  have been obscured. This has been done so that the relative location of cam lug  66  and cam-lug track  92  can be seen. Cam lug  66  extends down through cam-lug passage  46  (not shown for clarity), of charging handle base  40 , into cam-lug track  92 , of latch  90 . 
     In  FIG. 63 , first latch cam  93  of latch  90  is in contact with cam lug  66  of load portion  60 . In the illustrated embodiment, hook  91  is spaced from charging handle base  40 , creating gap C, in this configuration. Latch-spring  99 , which is compressed slightly as compared to  FIG. 61 , is still urging latch  90  to rotate in a clockwise direction but clockwise rotation of latch  90  is limited by contact with cam lug  66  of load portion  60  rather than contact of hook  91  of latch  90  with charging handle base  40  as shown in  FIG. 61 . Advantageously, such an arrangement maintains cam lug  66  and first latch cam  93  in close proximity so that clockwise rotation of load portion  60  during operation of the charging handle immediately begins moving the latch to an unlatched configuration. 
     Referring now to  FIG. 63 , which is identical to  FIGS. 62A and 62B , except with load portion  60  being sectioned rather than being transparent, the interaction between cam lug  66  and latch  90  can be clearly seen. Under pressure from latch-spring  99 , first latch cam  93  of latch  90  puts rearward pressure on cam lug  66 . Again, in some instances, load portion  60  may be limited from rotating farther in the counterclockwise direction because cam lug  66  is in contact with the rear of cam-lug passage  46  (not shown). 
     In  FIG. 64 , the charging handle has been assembled into a receiver  10  with hook  91  of latch  90  engaged into receiver notch  15 . Handle portion  50  is illustrated in the deployed (most acute angle “A”) position, and charging handle base  40  is illustrated in its forward position (i.e., minimum distance B). Cam-gap  80  exists between load portion  60  and rearward-facing surface  30  of receiver  10 . 
       FIG. 65  illustrates charging handle base  40 , handle portion  50 , and load portion  60  in the same position as shown in  FIGS. 12 and 13 . In  FIG. 65 , a rearward force has been applied to handle portion  50 . The rearward force has caused handle portion  50  and load portion  60  to rotate slightly (as compared to  FIG. 64 ), causing angle “A” to increase slightly. Cam-gap  80  has closed and load portion  60  is now in contact with rearward-facing surface  30  at fulcrum contact point  85 , but charging handle base  40  has not yet moved rearward (i.e. distance B has not yet increased). 
     Still referring to  FIG. 65 , the forward pressure of cam lug  66  has caused latch  90  to rotate in a counterclockwise direction. That is, cam lug  66  has pressed forward against, and slid along, first latch cam  93  causing latch  90  to pivot around latch pivot pin  110 . Accordingly, cam lug  66  has cammed first latch cam  93  downward (in the orientation shown in the figure). As can be seen latch-spring  99  has compressed slightly, and latch hook  91 , of latch  90 , has been rotated out of engagement with receiver notch  15 . 
     Latch hook  91  may be completely disengaged from receiver notch  15  before load portion  60  begins to force the charging handle rearward. For example, the space provided by cam-gap  80  may allow the camming action of cam lug  66  (acting against first latch cam  93 ) to open charging handle latch  90  before the charging handle is forced rearward. Advantageously, such an arrangement can reduce the possibility of hook  91  resisting withdrawal of the charging handle from the firearm upon actuation of the handle portion  50  and load portion  60  to extract the charging handle. 
     In  FIG. 66 , the charging handle has moved slightly rearward (i.e. distance-B has slightly increased) due at least in part to the force of load portion  60  against rearward-facing surface  30  at contact point  85 . As can be seen, cam lug  66  has rotated out of contact with first latch cam  93  and is now sliding over cam dwell  96 . Cam dwell  96  is configured to allow cam lug  66  to continue to move forward while latch  90  is held out of receiver notch  15 . Advantageously, the cam dwell  96  can allow load portion  60  to push the charging handle rearward a significant distance without significant further rotation of latch  90  and compression of latch-spring  99 . 
     Cam dwell  96  can allow the camming action of load portion  60  to accommodate manufacturing tolerances of the parts. For example, cam dwell  96  can allow load portion  60  to push the charging handle back sufficiently to ensure that when cam lug  66  begins to disengage from latch  90  that latch hook  91  is rearward of receiver notch  15 . 
       FIG. 67  illustrates the assembly after further rotation of handle portion  50  and load portion  60  and rearward movement of the charging handle. As can be seen, cam lug  66  has moved sufficiently forward as to disengage from cam dwell  96 . In fact, cam lug  66  has rotated out of engagement from latch  90 . In some instances, cam lug  66  may no longer be in contact with latch  90  due to latch hook  91  contacting a portion of the receiver rearward of the receiver notch  15  and, therefore, applying counterclockwise force to latch  90 . Preferably, load portion  60 , pressing on contact point  85 , is arranged to separate the charging handle from the receiver sufficiently that latch hook  91  cannot reengage with receiver notch  15  when cam lug  66  disengages from latch  90 . In other words, load portion  60  can be arranged such that cam lug  66  releases from latch  90  at a point in the charging handle&#39;s rearward movement where latch  90  cannot hook back into notch  15 . 
     Turning now to  FIG. 68 , handle portion  50  and load portion  60  have rotated in a clockwise direction to a position wherein cam lug  66  is in contact with the forward end of cam lug passage  46  of charging handle base  40 . The rearward force applied to handle portion  50  continues to move the charging handle rearward (increasing distance-B), separating load portion  60  from receiver  10 . As can be seen, cam lug  66  has completely disengaged from latch  90 , and latch  90 , being urged by latch-spring  99 , has rotated in a clockwise direction until hook  91  has stopped on the side of charging handle base  40 . 
     Resetting the charging handle is illustrated in  FIG. 69 . During a reset, cam lug  66  passes back through cam-lug track  92  as handle portion  50  and load portion  60  are rotated in a counterclockwise direction. During such rotation, cam lug  66  comes into contact with second latch-cam  94  of latch  90 . As cam lug  66  slides over second latch-cam  94 , latch  90  rotates in a counterclockwise direction. That is, cam lug  66  cams second latch-cam  94  down, allowing latch  90  to rotate out of the way of cam lug  66 . Continuing to rotate handle portion  50  and load portion  60  in this direction will eventually return handle portion  50  and load portion  60  to the position shown in  FIGS. 10 and 11 . 
       FIG. 70  illustrates that latch  90  can be actuated manually by depressing latch-button  97 . That is, latch  90  can be actuated in the same manner as a latch. In other words, latch  90  can be actuated separately from handle portion  50  and load portion  60 . 
       FIGS. 71A-71C  illustrate an embodiment in which handle portion  50 , load portion  60  and spline shaft  70  (of previous Figures) have been combined into lever  256 . Lever  256  operates in the same way as the handle portion  50 , load portion  60  and spline shaft  70  of the preferred embodiment. 
     Lever  256  includes a pivot shaft  270  that extends through and pivots within spline pivot hole  45  of charging handle base  40 . Lever  256  can be held assembled to charging handle base  40  by a pivot shaft retainer pin  280 , assembled into pivot shaft retainer hole  275 . Additionally or alternatively, another retention device (roll/taper/spring/etc. pins, retaining rings/clips/etc.) may be used and/or the bottom end of the pivot shaft  270  may be expanded (e.g., mushroomed) after assembly to retain lever  256  in association with charging handle base  40 . 
       FIGS. 72A-72C  illustrate an embodiment wherein the lever is removable from charging handle base  40 . In this embodiment, removable lever  356  includes handle portion  50 , load portion  60  and spline shaft  70 ; however, lever  356  can be disassembled from charging handle base  40  without requiring a tool and/or removal of a retainer pin. 
       FIGS. 73A-75  illustrate an embodiment of a lever that is backwards compatible with charging handle  20 .  FIGS. 73A-73C  show the profile of backwards compatible lever  456  is similar to that of the previous figures of handle portion  50  and load portion  60 , lever  256 , and removable lever  356 . It can also be seen that a lip  470  protrudes from the bottom of backwards compatible lever  456  in similar manner as did pivot shaft of removable lever  356  (of  FIG. 21B ). However, in this illustration, lip  470  is configured to interface with the forward surface of a charging handle. 
       FIGS. 74A-74C  illustrate the backwards compatible lever  456  interfacing with charging handle  20 , wherein lip  470  is engaged with a front face of charging handle  20 . 
     As shown in  FIG. 75 , lip  470  of backwards compatible lever  456  can automatically actuate latch  25 . 
     While the levers illustrated and described above have been first class levers, it is envisioned that a second class lever could be employed to multiply the removal force applied to the charging handle by a user. For example, the contact point  85  between the lever and the firearm could be positioned in an area between the spline shaft and the portion of lever that extends laterally away from the firearm (e.g., the handle). In such an arrangement a user would force the lever forward to try and separate the charging handle end from the firearm. 
     Additionally, while the above embodiments have illustrated and described a lever as the simple machine for multiplying force to remove the charging handle, other simple machines are envisioned as well. For example, the charging handle may include a screw that, when rotated, forces the charging handle away from the receiver of the firearm. Similarly, the charging handle may include one or more pulleys and cords that extend rearward from the charging handle to, for example, the buttstock. Accordingly, upon actuation of the cord, the charging handle may be forced rearward. 
     While the fulcrum (e.g., spline shaft) for illustrated embodiments is shown as being on the same side of the longitudinal axis of the charging handle as the handle portion  50 , the fulcrum can be positioned on the opposing side of the longitudinal axis. Alternatively, rather than being offset from the longitudinal axis of the charging handle, the fulcrum may be aligned vertically with the longitudinal axis, the contact point, and/or both. Advantageously, such an arrangement can reduce the torsional force between the charging handle base and the receiver when force is applied to the lever. 
     While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only the preferred embodiment has been shown and described and that all changes, equivalents, and modifications that come within the spirit of the inventions defined by following claims are desired to be protected. All publications, patents, and patent applications cited in this specification are herein incorporated by reference as if each individual publication, patent, or patent application were specifically and individually indicated to be incorporated by reference and set forth in its entirety herein. 
     The following numbered clauses set out specific embodiments that may be useful in understanding the present invention: 
     1. A charging handle for a firearm comprising: 
     a charging handle base having a first end and a second end; 
     the first end arranged for positioning within the firearm; 
     the second end having a charging handle latch pivotably attached thereto, the charging handle latch arranged to engage another part of the firearm to retain the second end in position; and 
     a pivoting charging handle removal lever coupled to the charging handle base, the pivoting charging handle removal lever having three separate locations to achieve a mechanical advantage:
         (a) a first location which engages the charging handle base or the charging handle latch,   (b) a second location which engages a different part of the firearm than the charging handle base or the charging handle latch, and   (c) a third location exposed for application of manual force and positioned to achieve a mechanical advantage for releasing the charging handle when stuck in the firearm.       

     2. The charging handle of clause 1, wherein the first location is positioned in an area between the second location and the third location. 
     3. The charging handle of any preceding clause, wherein the pivoting charging handle removal lever disengages the charging handle latch from the firearm when actuated. 
     4. The charging handle of any preceding clause, wherein the pivoting charging handle includes a cam-lug that rotates the charging handle latch away from the charging handle base during rotation of the pivoting charging handle removal lever. 
     5. The charging handle of any preceding clause, wherein the pivoting charging handle removal lever includes a handle portion extending from the first location to the third location and a load portion extending from the first location to the second location; and 
     wherein the handle portion is selectively pivotable relative to the load portion so as to configure the pivoting charging handle removal lever from stored configuration to a deployed configuration. 
     6. The charging handle of any preceding clause, wherein the handle portion is coupled to the load portion by a spline shaft having splines; and 
     wherein the handle portion and load portion each have spline openings having one or more teeth and gaps sized to engage the spline shaft. 
     7. The charging handle of clause 6, wherein the spline shaft, the handle portion, and the load portion are arranged such that the spline shaft rotationally couples the handle portion and the load portion in one or two configurations. 
     8. The charging handle of clause 6 or 7, wherein the spline shaft has a first circumferential portion that, when positioned within the spline opening of the load portion, rotationally locks the spline shaft relative to the load portion; and 
     wherein the spline shaft has a second circumferential portion that, when positioned within the spline opening of the load portion, allows at least 50 degrees of rotation of the load portion relative to the spline shaft. 
     9. The charging handle of any preceding clause, wherein the charging handle is for an AR style firearm. 
     10. The charging handle of any preceding clause, wherein: 
     the first end of the charging handle base defines an opening arranged to receive a portion of a bolt carrier group of the firearm. 
     11. A charging handle for a firearm comprising: 
     a charging handle base having a first end and a second end; 
     the first end arranged for positioning within a housing of the firearm; 
     the second end having a charging handle latch pivotably attached thereto, the charging handle latch arranged to engage the firearm to retain the second end in fixed position relative to the housing; and 
     a rearward-assist member arranged to provide a mechanical advantage upon application of a force to move the second end of the charging handle base away from the housing when the charging handle latch is disengaged from the firearm. 
     12. The charging handle of clause 11, wherein: 
     when the rearward-assist member disengages the charging handle latch from the housing when actuated. 
     13. The charging handle of clause 11 or 12, wherein: 
     the rearward-assist member is a simple machine. 
     14. The charging handle of any one of clauses 11-13, wherein: 
     the simple machine is a lever pivotably coupled to the charging handle base, the lever having three separate locations to achieve a mechanical advantage:
         (a) a first location pivotably coupled to the charging handle base,   (b) a second location which engages the firearm, and   (c) a third location comprising a handle for contact with a user&#39;s hand.       

     15. The charging handle of clause 14, wherein the first location is positioned in an area between the second location and the third location. 
     16. The charging handle of any one of clauses 11-15, wherein the lever includes a cam-lug that rotates the charging handle latch away from the charging handle base during rotation of the lever. 
     17. The charging handle of any one of clauses 14-16, wherein the lever includes a handle portion extending from the first location to the third location and a load portion extending from the first location to the second location; and 
     wherein the handle portion is selectively pivotable relative to the load portion so as to configure the lever from stored configuration to a deployed configuration. 
     18. The charging handle of clause 17, wherein the handle portion is coupled to the load portion by a spline shaft having splines; and 
     wherein the handle portion and load portion each have spline openings having one or more teeth and gaps sized to engage the spline shaft 
     19. The charging handle of any one of clauses 11-18, wherein the charging handle is for an AR style firearm. 
     20. The charging handle of any one of clauses 11-19, wherein: 
     the first end of the charging handle base defines an opening arranged to receive a portion of a bolt carrier group of the firearm.