Patent Publication Number: US-11029104-B2

Title: Firearm system

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a divisional of U.S. patent application Ser. No. 16/017,819 filed Jun. 25, 2018, which is a continuation of U.S. patent application Ser. No. 14/823,110 filed Aug. 11, 2015 (now U.S. Pat. No. 10,006,727), which claims the benefit of priority to U.S. Provisional Patent Application No. 62/062,143 filed Oct. 9, 2014, U.S. Provisional Patent Application No. 62/062,141 filed Oct. 9, 2014, and U.S. Provisional Patent Application No. 62/036,096 filed Aug. 11, 2014, the disclosures of all of which are hereby incorporated by reference in their entireties. 
     A portion of the disclosure of this patent document contains material that is subject to copyright protection. The copyright owner has no objection to the reproduction of the patent document or the patent disclosure, as it appears in the U.S. Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever. 
    
    
     BACKGROUND 
     The present invention relates to firearms, specifically the M240 machine gun and variants thereof. More particularly, the invention pertains to an adapter for the M240 machine gun so as to increase the mobility and usability of the firearm. Optionally, an adapter may be utilized on the bottom side of the receiver to move both the trigger and grip forward, closer to the muzzle of the firearm, so that a shorter overall length can be achieved. In some optional embodiments, the M240 machine gun may include an adapter that replaces the floor of the receiver or alternatively, in further optional embodiments, the M240 machine gun may include a trigger assembly with a proximal leg that engages the traditional trigger housing assembly engagement of the receiver of the M240 machine gun. 
     The M240 machine gun has generally been used by the United States military since at least about the late 1970s. Currently, the firearm has multiple applications being used by both infantry as well as with vehicles, both on land and on water. In use, the M240 machine gun is often fired from an integrated bipod or from a mount that may be attached to a vehicle or a fixed location. While not the lightest machine gun in use, the firearm is very reliable and relatively standardized among the NATO countries. 
     Historically, the M240 machine gun was modeled after features of the Browning machine gun of 1919 and the Browning automatic rifle of 1918. Through this thinking, the M240 developed with a box-type receiver with the shoulder stock placed on the rear of the receiver. As such, the trigger location is very near the end of the stock of the firearm. Otherwise stated, the M240 machine gun provides its grip at about the rearmost portion of the bottom of the receiver near where the stock connects to the receiver of the firearm. The stock must extend from the rear of the receiver of the M240 machine gun a significant length so as to provide an appropriate length of pull. Generally, the length of pull is based on about the average person&#39;s length of pull measured from their bent trigger finger to the person&#39;s bend in their arm. With the design of the M240 machine gun, the stock must provide the great majority of the length of pull as the grip and trigger are so near the rear of the receiver of the firearm. 
     Unfortunately, this design of the M240 machine gun provides unnecessary length and weight to the firearm making it more cumbersome than necessary. Thus, existing M240 machine guns can be difficult to transport by an individual, especially as it must often be carried into combat situations. What is desired therefore is an M240 machine gun having a more ergonomic shape and possibly decreased weight, wherein the trigger and grip are moved distally toward the muzzle of the firearm so that a shorter stock may be used with the M240 machine gun. 
     SUMMARY 
     As used herein, “proximal” refers to a longitudinal direction closer to the butt stock of the firearm, and “distal” refers to a longitudinal direction closer to the muzzle of the firearm. When “proximally” is used herein to describe the relationship between parts, the term denotes that the part located proximally is closer to the butt stock than the other part. When “distally” is used herein to describe the relationship between parts, the term denotes that the part located distally is closer to the muzzle than the other part. 
     Also as used herein, M240 refers to the family of belt-fed, gas operated machine guns which generally fire the 7.62×51 mm NATO cartridge. Further as used herein, the term “M240” is generally synonymous with the Belgian FN MAG58 machine gun and is used to include variants. Variants of the M240 machine gun may include but are not limited to the M240B, M240C, M240D, M240G, M24011, M240L, M240E1 and E5, M240L, and M240LW. While discussions of various optional embodiments may describe specific variants of the M240 machine gun, the use of “M240” is intended to include all variants so long as feasible, including when also present in the claims Also, to the extent semi-automatic versions and/or single shot variants of the M240 machine gun exist, the use of “M240” is intended to include these variants so long as feasible. 
     As additionally used herein, the term “adapter” and “interface” may be used interchangeably and refer to optional embodiments of the invention which allow for the trigger housing assembly to be moved distally forward to provide for a more ergonomic and shorter M240 machine gun. In optional embodiments, the adapter may be used with an existing receiver for an M240 machine gun, replacing the bottom plate of the receiver. 
     In accordance with one optional aspect, an adapter for an M240 machine gun has a proximal end and a distal end and is connectable to an M240 machine gun receiver to replace the receiver floor of the M240 machine gun receiver; the adapter also having an ejection port, trigger housing assembly engagement, trigger opening, and receiver floor wall. The ejection port may be located at about the distal end of the adapter and the trigger opening located near the ejection port and positioned proximally. The trigger housing assembly engagement may be positioned proximally to the trigger opening with the adapter floor wall positioned proximally to the trigger opening wherein the adapter locates an attachable trigger housing assembly from a proximal receiver position to a forward receiver position. 
     In accordance with another optional aspect, the adapter may further include a mounting hole positioned distal to both the adapter floor wall and trigger opening and positioned proximal to the ejection port. 
     In accordance with other optional aspects, the trigger housing assembly may include a removable grip wherein the removable grip may be compatible with AR15/M16 firearm types. 
     In accordance with another optional aspect, the trigger housing assembly engagement of the adapter is at least about two inches from the proximal end of the adapter. 
     In accordance with yet another optional aspect, the adapter further includes a cheek weld to optionally replace a rear sight of the machine gun. 
     In accordance with another optional aspect, an extended trigger housing assembly for an M240 machine gun is provided which has a proximal end and a distal end and is connectable to an M240 machine gun receiver. The trigger housing assembly may also have a proximal leg to connect to a trigger housing assembly engagement of the M240 machine gun receiver wherein the extended trigger housing assembly positions the trigger housing assembly to a forward receiver position. 
     In accordance with another optional aspect, the trigger housing assembly may comprise a removable grip. 
     In accordance with still another optional aspect, the trigger of the trigger housing assembly is located distally to a mounting hole on the M240 machine gun receiver when attached. 
     In accordance with another optional aspect, a new M240 machine gun is provided which includes an M240 machine gun having a receiver with a floor, top, proximal end, and distal end; a butt stock connected to a proximal end of the receiver; a barrel connected to a distal end of the receiver; and a trigger housing assembly with a grip, the trigger housing assembly attached to the floor of the receiver and positioned in a forward position with the grip spaced distally from the proximal end of the receiver. 
     In accordance with another optional aspect, a new M240 machine gun may have a receiver with a floor that includes an ejection port, trigger opening, and receiver floor wall, wherein the trigger opening is positioned between the receiver floor wall and the ejection port. 
     In accordance with another optional aspect, a new M240 machine gun may include a receiver with a mounting hole positioned distal to both the receiver floor wall and trigger opening and positioned proximal to the ejection port. 
     In accordance with another optional aspect, a new M240 machine gun may include a trigger housing assembly with a proximal leg for engaging a trigger housing assembly engagement on the receiver with the trigger housing assembly engagement located at about the proximal end of the receiver. 
     In accordance with another optional aspect, a new M240 machine gun may include an operating rod with a sear engagement located distally from the operating rod&#39;s rear body portion. 
     In accordance with other optional aspects, a new M240 machine gun may include a shortened butt stock. Also, the butt stock may have a top surface that is about even with the top surface of the receiver. 
     In accordance with another optional aspect, a new M240 machine gun may have a cheek surface on the top of the receiver. 
     In accordance with other optional aspects, a new M240 machine gun may include a receiver formed from a unitary first shell and a unitary second shell. Furthermore, the union of the unitary first shell and the unitary second shell may form the ejection port and trigger opening with the trigger housing assembly of the new M240 machine gun attached in a forward position. 
     In accordance with another optional aspect, a new M240 machinegun may position a proximal end of the grip of the trigger housing assembly at least about two inches from proximal end of the receiver. 
     In accordance with one optional aspect, a handguard for a machine gun has a first side, a second side, a bottom side as well as an exterior surface and an interior surface with the interior surface of the handguard having one or more bosses to engage one or more slots on a receiver of the machine gun. 
     In accordance with another optional aspect, the handguard may further include an interface system on at least one side for accessory components. The interface system may include a variety of interface systems that may be used for firearms which includes both KeyMod as well as Picatinny rails. 
     In accordance with other optional aspects, the handguard may include a bipod attachment and in some optional embodiments the bipod attachment may be a pintle mount. 
     In accordance with another optional aspect, the interior surface of the handguard may include two bosses to engage two slots on the receiver of the machine gun. 
     In accordance with yet another optional aspect, the handguard may further include one or more attachment points on one or more sides of the handguard to correspond to one or more mounting points on the receiver of the machine gun. 
     In accordance with another optional aspect, attachment hardware may be included that engages the one or more attachment points on the one or more sides of the handguard and the one or more mounting points on the receiver of the machine gun. Such attachment hardware may include screws, such screws optionally being #10-32 screws. 
     In accordance with another optional aspect, three or more attachment points on the first side of the handguard may correspond to three or more mounting points on the first side of the receiver and three or more attachment points on the second side of the handguard may correspond to three or more attachment points on the second side of the receiver. 
     In accordance with another optional aspect, a handguard for an M240LW machine gun is provided with a first side, a second side, and a bottom side, an exterior surface and an interior surface. The interior surface of the handguard having one or more bosses to engage one or more slots on a receiver of the M240LW machine gun; the first side having one or more attachment points to correspond to one or more mounting points on a first side of the receiver of the M240LW machine gun; the second side having one or more attachment points to correspond to one or more mounting points on a second side of the receiver of the M240LW machine gun; and one or more of the sides having an interface system for accessory components. 
     In accordance with yet another optional aspect, the handguard may include one or more bosses on the interior surface of the first side of the handguard and one or more bosses on the interior surface of the second side of the handguard. 
     In accordance with still another optional aspect, each side of the handguard may include an interface system for accessory components. 
     In accordance with another optional aspect, a method of installing a handguard on a machine gun is provided which includes the steps of having a machine gun with a receiver; providing a handguard comprising a first side, a second side and a bottom side, an exterior surface and an interior surface, the interior surface of the handguard having one or more bosses to engage one or more slots on a receiver of the machine gun, and the one or more sides including attachment points to correspond to mounting points on the receiver; fitting the handguard onto the receiver of the machine gun with the bosses of the interior surface of the handguard engaging the slots on the receiver of the machine gun; aligning the attachment points of the handguard with the mounting points of the receiver of the machine gun; and engaging aligned attachment points and mounting points with attachment hardware. 
     In accordance with yet another optional aspect, the steps of installing a handguard on a machine gun may further include three aligned attachment points and mounting points engaged with attachment hardware on the first side of the handguard and three aligned attachment points and mounting points engaged with attachment hardware on the second side of the handguard. The attachment hardware may comprise screws which may be #10-32 screws. 
     In still another optional aspect, a bipod assembly for mounting to a handguard may include a main bipod body; a first leg and a second leg attached to the main bipod body, each leg being rotatably attached; a pintle on the main bipod body for attaching to a pintle mount of the handguard; and one or more bosses adjacent to the pintle for limiting rotational travel of the bipod assembly when it is engaged to the handguard. 
     In accordance with other optional aspects, the bipod assembly may include two bosses adjacent to the pintle on the main bipod body. 
     In accordance with another optional aspect, the bipod assembly may be removably attachable to the handguard. 
     Further optional aspects include an adapter for an M240 machine gun for connecting to a receiver of an M240 machine gun. The adapter may have an ejection port located at about the distal end of the adapter and a trigger opening near the ejection port and positioned proximally. In such optional aspects, the adapter moves an attached trigger assembly distally forward compared to a conventional M240 machine gun. 
     As used herein, the term “engage” means to interact with, interlock with, associate with or communicate with. 
     The term “providing,” and forms thereof, are used in a broad sense, and are referred to, but are not limited to making available for use, enabling usage, giving, supplying, obtaining, getting hold of, acquiring, making ready for use, and/or placing into position ready for use. 
     Aside from the structural and procedural arrangements set forth above, the invention could include a number of other arrangements, such as those explained hereinafter. It is to be understood, that both the foregoing description and the following description are exemplary. 
     The accompanying drawings are incorporated in and constitute a part of the specification. The drawings illustrate optional embodiments of the invention and together with the description serve to explain some principles of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an illustration of a prior art M240 machine gun. 
         FIG. 2  is an illustration of a prior art bottom portion of a receiver of an M240 machine gun. 
         FIG. 3  is an illustration of an optional embodiment of an M240 machine gun with adapter to move a trigger housing assembly distally forward. 
         FIG. 4  is an illustration of an optional embodiment of the adapter for an M240 machine gun. 
         FIG. 5  is an illustration of an optional embodiment of an M240 machine gun having a trigger assembly with proximal leg. 
         FIG. 6  is an illustration of an optional embodiment of a trigger assembly with proximal leg for an M240 machine gun. 
         FIG. 7  is an illustration comparing the M240 machine gun of  FIG. 1  to the M240 machine gun of  FIG. 5  to the M240 machine gun of  FIG. 3 . 
         FIG. 8  is an illustration of a prior art M240LW machine gun. 
         FIG. 9  is an illustration of an M240LW machine gun with the trigger housing assembly located distally forward. 
         FIG. 10  is an illustration of an M240LW machine gun with a trigger housing assembly with proximal leg. 
         FIG. 11  is an illustration comparing the M240LW machine gun of  FIG. 8  to the M240LW machine gun of  FIG. 10  to the M240 machine gun of  FIG. 9 . 
         FIGS. 12 a  and 12 b    are illustrations of an operating rod assembly for an M240 machine gun. 
         FIGS. 13 a  and 13 b    are illustrations of an operating rod assembly with the sear engagement located distally forward. 
         FIGS. 14 a  and 14 b    are illustrations of a sight for an M240 machine gun. 
         FIGS. 15 a  and 15 b    are illustrations of a cheek surface for an M240 machine gun. 
         FIG. 16  is an illustration of a cutaway view of an optional embodiment of the operating rod. 
         FIG. 17  is an illustration of an optional embodiment of a top rail. 
         FIG. 18  is an illustration of an optional embodiment of a top rail with a raised rear sight. 
         FIG. 19  is an illustration of an optional embodiment of a top rail mounted on an optional embodiment of a machine gun. 
         FIG. 20  is an illustration of an optional embodiment of a handguard attached to a machine gun. 
         FIG. 21  is an illustration of an optional embodiment of the handguard attached to a machine gun. 
         FIG. 22  is an illustration of an optional embodiment of the handguard with an optional embodiment of the bipod assembly attached. 
         FIG. 23  is an illustration of an optional embodiment of the handguard with an optional embodiment of the bipod assembly attached. 
         FIG. 24  is an illustration of a side perspective view of an optional embodiment of the handguard. 
         FIG. 25  is an illustration of a front view of an optional embodiment of the handguard. 
         FIG. 26  is an illustration of the receiver of a machine gun where the receiver communicates with an optional embodiment of the handguard. 
         FIG. 27  is an illustration of a close up view of an optional embodiment of the handguard attached to a machine gun. 
         FIG. 28  is an illustration of a close up view of an optional embodiment of the handguard attached to a machine gun. 
         FIG. 29  is an illustration of an exploded view of the machine gun without barrel with an optional embodiment of the handguard and an optional embodiment of a bipod assembly. 
         FIG. 30  is an illustration of an optional embodiment of the handguard with the receiver of a machine gun. 
         FIG. 31  is an illustration of a cross-sectional view of an optional embodiment of the handguard attached to a machine gun. 
         FIG. 32  is an illustration of an optional embodiment of a bipod assembly. 
     
    
    
     Reference will now be made in detail to optional embodiments of the invention, examples of which are illustrated in accompanying drawings. Whenever possible, the same reference numbers are used in the drawings and in the description referring to the same or like parts. 
     DETAILED DESCRIPTION 
     While the making and using of various embodiments are discussed in detail below, it should be appreciated that the present invention provides many applicable inventive concepts that can be embodied in a wide variety of specific contexts. The specific embodiments discussed herein are merely illustrative of specific ways to make and use the invention and do not delimit the scope of the invention. 
     Where the various figures may describe embodiments sharing various common elements and features with other embodiments, similar elements and features are given the same reference numerals and redundant description thereof may be omitted below. Generally, different, but similar reference numbers (e.g.  42  and  142 ) will be used to show that some parts are replaced. Numerals that indicate proximal and distal will generally stay the same even though they might be for different locations on different elements. 
     Conditional language used herein, such as, among others, “can,” “might,” “may,” “e.g.,” and the like, unless specifically stated otherwise, or otherwise understood within the context as used, is generally intended to convey that certain embodiments include, while other embodiments do not include, certain features, elements and/or states. Thus, such conditional language is not generally intended to imply that features, elements and/or states are in any way required for one or more embodiments or that one or more embodiments necessarily include logic for deciding, with or without author input or prompting, whether these features, elements and/or states are included or are to be performed in any particular embodiment. 
     To the extent that the term “includes” or “including” is used in the specification or the claims, it is intended to be inclusive in a manner similar to the term “comprising” as that term is interpreted when employed as a transitional word in a claim. Furthermore, to the extent that the term “or” is employed (e.g., A or B) it is intended to mean “A or B or both.” Furthermore, to the extent the term “connect” is used in the specification or claims, it is intended to mean not only “directly connected to,” but also “indirectly connected to” such as connected through another component or multiple components. 
     To facilitate the understanding of the embodiments described herein, a number of terms are defined below. The terms defined herein have meanings as commonly understood by a person of ordinary skill in the areas relevant to the embodiments described herein. Terms such as “a,” “an,” and “the” are not intended to refer to only a singular entity, but rather include the general class of which a specific example may be used for illustration. The terminology herein is used to describe specific embodiments of the invention, but their usage does not delimit the invention, except as set forth in the claims. 
     Referring to  FIG. 1 , there is an illustration of a prior art M240 machine gun designated by numeral  10 . Generally, such firearm is manufactured by Fabrique Nationale. The M240 machine gun  10  includes butt stock  12 , barrel  14 , muzzle  16  and receiver  18 . Generally, distal end of receiver  18  is designated by numeral  20  and proximal end of receiver  18  is designated by numeral  22 . Trigger housing assembly  24  includes grip  25  and trigger  32 . Receiver  18  of machine gun  10  includes receiver floor  42 . Alternatively, the term “bottom” may be used interchangeably with “floor” and mean the same. Receiver floor  42  of receiver  18  includes trigger assembly engagement  26  and mounting point  28 . Generally, the prior art M240 machine gun  10  is understood to have a conventional box-like receiver assembled from separate parts, with overlapping plate edges that are riveted together. 
     Receiver floor  42  further includes ejection port  30  for fired brass to be expended from the firearm. Generally, the M240 machine gun  10  has a butt stock length designated by numeral  36 . Butt stock length  36  is a length of distance from the proximal end of the butt stock to the distal end of the butt stock where it connects to the proximal end of receiver  18 . The length of pull of the M240 machine gun  10  is designated by numeral  38  and is generally understood to be the distance from trigger  32  to the proximal end of butt stock  12 . The overall length of the firearm is indicated by numeral  40 . 
     Referring now to  FIG. 2 , there is an illustration of a M240 machine gun&#39;s receiver floor, previously designated by numeral  42 . This is generally riveted to receiver  18  of the FN variety prior art M240 machine gun designated by numeral  10  and illustrated in  FIG. 1 . Receiver floor  42  includes distal end  44  and proximal end  46 . As previously described, receiver floor  42  also includes first trigger assembly engagement  26  and mount point  28 . Between first trigger assembly engagement  26  and mount point  28 , trigger opening  48  is positioned so that trigger  32  of trigger housing assembly  24  may pass there between in connecting with the fire control components within the receiver (not shown). Between trigger opening  48  and ejection port  30 , there is receiver floor wall  34 . In embodiments of the prior art FN M240 machine gun as illustrated in  FIG. 1 , receiver floor  42  positions the trigger housing assembly  24  so that the end of grip  25  is about even with proximal end  22  of receiver  18 . Generally, trigger opening  48  is located toward the proximal end of receiver floor  42  and ejection port  30  is located toward the distal end of receiver floor  42  with receiver floor wall  34  positioned there between. 
     Referring to  FIG. 3 , there is an optional embodiment of applicant&#39;s invention designated by numeral  110 . More specifically,  FIG. 3  illustrates an M240 machine gun having adapter  142  in place of receiver floor  42 . M240 machine gun  110  includes butt stock  112 , barrel  14 , muzzle  16  and receiver  18  (since the receiver includes many of the same features as in  FIG. 1 , absent the receiver floor, the receiver in  FIG. 3  is still indicated by the numeral  18 ). Receiver  18  includes distal end  20  and proximal end  22 . In having bottom adapter  142 , new M240 machine gun  110  with receiver  18  includes adapter  142  with adapter floor wall  134  between the proximal end  22  of receiver  18  and trigger housing assembly engagement  126 . Furthermore, adapter  142  includes trigger housing assembly engagement  126  so that trigger housing assembly  24  can be attached to new M240 machine gun  110  via the engagement in conjunction with trigger opening  148 . Trigger assembly  24  further includes grip  25  and trigger  32 . In front of trigger assembly  24  is ejection port  130 . Otherwise stated, ejection port  130 , through which spent brass is sent, is located between distal end  20  and trigger housing assembly  24  of receiver  18 . The use of adapter  142  does not require the relocation of the ejection port. Furthermore, the mounting point is indicated by numeral  128 . 
     Advantageously, trigger housing assembly  24  is moved distally forward when compared to the prior art M240 machine gun as appears in  FIG. 1 . In some optional embodiments, trigger housing assembly is moved inches forward, some optional embodiments have the trigger housing assembly moved greater than two inches distally. In some further optional embodiments, the trigger housing assembly may be moved greater than three inches distally. In yet more optional embodiments, the trigger housing assembly may be moved about 3.3 inches distally. Otherwise stated, trigger housing assembly  24  can be considered to be roughly in about the middle of adapter  142 . Further advantageous is that a conventional trigger housing assembly can be utilized in this new location. In some optional embodiments, the overall length  140  of the new M240 machine gun designated by numeral  110  may be shorter than the overall length  40  of the traditional M240 machine gun designated by numeral  10  and illustrated in  FIG. 1 . 
     By having trigger assembly  24  moved forward, butt stock length  136  of butt stock  112  may be shorter than butt stock length  36  of butt stock  12  of the prior art M240 machine gun  10  while achieving a sufficient length of pull. This is illustrated by comparing butt stock length  36  of  FIG. 1  to that of butt stock length  136  of  FIG. 3 . However, length of pull  138  of the new M240 machine gun of  FIG. 3  may be substantially similar to that of length of pull  38  of the prior art M240 machine gun of  FIG. 1  as trigger assembly  24  of M240 machine gun  110  has moved forward with the firearm having a shorter butt stock  112 . The overall length  140  of the M240 machine gun as embodied in  FIG. 3  may also be shorter than that of overall length  40  of  FIG. 1 . 
     Additionally, the M240 machine gun as designated by numeral  110  in  FIG. 3  may have an improved balance as trigger assembly  24  with grip  25  is moved forward thus helping further distribute the weight of the firearm. Optionally, in further optional embodiments, butt stock  112  may be of an adjustable design so that a customizable length of pull may be realized. In some optional embodiments, buttstock  112  may include an internal piston or hydraulic design that assists in the function of M240 machine gun  110 . 
     Referring now to  FIG. 4  there is an illustration of adapter  142  which is utilized to move trigger assembly  24  forward as seen in  FIG. 3 . Generally, adapter  142  is understood to replace receiver floor plate  42  of a traditional M240 machine gun. Most conventional M240 machine guns have a riveted box receiver design and thus the existing receiver floor plate  42  can be removed and adapter  142  riveted in place instead. In other optional embodiments, adapter  142  may be attached in different manners to the receiver. 
     Generally, adapter  142  includes distal end  44  and proximal end  46 . Adapter floor wall  134  is proximally located to trigger opening  148  and thus also adjacent to about proximal end  46  of adapter  142 . Trigger opening  148  is understood as being between adapter floor wall  134  and ejection port  130  of adapter  142 . As previously mentioned, bottom plate adapter  142  can also include trigger assembly engagement  126  and mounting point  128 . Trigger opening  148  is thus positioned between trigger assembly engagement  126  and mounting point  128  if included, with ejection port  130  distal to trigger opening  148 . 
     In yet further optional embodiments, the adapter may be formed of a variety of different metals including various forms of steel and the like. In yet further optional embodiments it is possible that adapter  142  could be formed of various other alloys and metals including aluminum and further could also possibly be formed of different composite materials. Further possibilities include the formation of adapter from plastic materials. 
     Referring now to  FIG. 5 , there is an additional optional embodiment of M240 machine gun  110 . In comparing and contrasting the new M240 machine gun  110  of  FIG. 5  with the FN M240 machine gun as illustrated in  FIG. 1 , the butt stocks and trigger housing assemblies are different (as well as some internals). Here, as detailed in the illustration of  FIG. 5 , trigger  132  is also moved distally, similarly to the M240 machine gun as illustrated in  FIG. 3 , however, adapter  142  is not utilized. Rather, extended trigger housing assembly  124  is used to facilitate the distal relocation of trigger  132 . Notably, in such embodiments, the receiver floor plate  42  may remain as it is in  FIG. 1  (as well as receiver  18 ), as extended trigger housing  124  may fit to the original receiver floor of an M240 machine gun. 
     Extended trigger housing assembly  124  includes proximal leg  150 . With proximal leg  150  of extended trigger housing assembly  124 , extended trigger housing assembly  124  can engage trigger housing assembly engagement  26  to be secured to receiver  18  of new M240 machine gun  110 . Proximal leg  150  provides the necessary length and linkage so that grip  125  and trigger  132  can be moved distally forward so that butt stock  112  has a shorter butt stock length  136 . Thus, overall length  140  of M240 machine gun  110  as depicted in  FIG. 5  may be shorter than the prior art as depicted in  FIG. 1 . Advantageously, length of pull  138  may be generally maintained due to extended trigger housing assembly  124  positioning grip  125  and trigger  132  distally forward. In optional embodiments, trigger  132  connects to fire components of the M-240 machine gun through a linkage or the like so that the original opening for the trigger for the machine gun could be used. However, in further optional embodiments, a new trigger opening may be formed in the existing receiver so that the trigger assembly could engage with the fire components in that manner. Furthermore, such extended trigger housing assemblies  124  may facilitate a removable grip  125  that may also be compatible with AR15/M16 style grips. 
     In yet further optional embodiments, another slightly different extended trigger housing assembly  124  is illustrated in  FIG. 6  which may be formed of a variety of materials including a variety of metals, alloys and the like as well as composites and/or plastics. In optional embodiments, extended trigger housing assembly  124  with proximal leg  150  may be generally formed or milled of one entire piece of material. In yet further optional embodiments, extended trigger housing assembly  124  may be extruded, milled, cast or formed in a variety of other different manners. Additionally, extended trigger housing assembly  124  may be of a unitary piece or alternatively may be formed of a variety of different pieces combined together. As previously discussed, extended trigger housing assembly  124  may include grip  125 , trigger  132 , with proximal leg  150  engaging trigger housing assembly engagement  26 . 
     Referring now to  FIG. 7 , there is a comparison of the original prior art FN M240 machine gun as designated by numeral  10  with the two previously described embodiments of the new M240 machine gun designated by numeral  110 . This comparison illustration shows the shorter overall length using either the adapter or extended trigger assembly housing which further advantageously provides greater balance to the firearm. 
     Referring now to  FIG. 8 , there is an illustration of a M240LW machine gun as designed by Barrett Firearms Manufacturing. Generally the M240LW is a M240 variant which uses a unitary first shell and a unitary second shell to create the receiver for the firearm. Such firearm is described in U.S. Pat. No. 7,937,877, issued to Christopher Gene Barrett and entitled “Light Weight Firearm and Method of Manufacturing.” U.S. Pat. No. 7,937,877 is incorporated by reference in its entirety with respect to  FIGS. 8-11  to the extent that language from the reference does not conflict with the present disclosure. Generally, the M240LW is designated by numeral  210  and can incorporate conventional trigger housing assembly  24  having grip  25  and trigger  32 , the trigger housing assembly attaching to receiver  218  via trigger assembly engagement  226 . The ejection port is indicated by numeral  230 . Generally, conventional butt stock  12  can also be used with the M240LW. Such M240LW machine gun also has butt stock length  236 , length of pull  238  and overall length  240 . As with the other embodiments, the proximal end is indicated by numeral  22  and the distal end is indicated by numeral  20 . 
     Referring now to  FIG. 9 , there is a new embodiment which incorporates trigger housing assembly  24 , with grip  25  and trigger  32 , in a forward position. However, rather than using adapter  142  and incorporating it into an existing receiver as done with the embodiment in  FIG. 2 , the new machine gun designated by the numeral  310  may include the necessary arrangement for the forward position of trigger housing assembly  24  as part of the shells that form receiver  318 . 
     Generally, the trigger housing assembly engagement  326  of receiver  318  is positioned more distally than that of receiver  218 . The trigger opening (not shown) may be located between trigger housing assembly engagement  326  and mounting point  328 , with receiver floor wall  334  proximal to trigger housing assembly engagement  326 . Otherwise stated, in order from proximal end  22  of receiver  318  are receiver floor wall  334 , trigger housing assembly engagement  326 , trigger opening (not visible), and ejection port  330 , then the distal end  20 . Optionally butt stock  112  may be used with such an embodiment of the machine gun. 
     Generally, the benefits of machine gun  310  of  FIG. 9  are similar to those as previously described for M240 machine gun  110  of  FIG. 2 , but with additional improvements. As the M240LW machine gun variant is already lighter than the traditional M240 machine gun, the additional decrease in length of machine gun  310  with a clamshell design provides for even greater maneuverability than the M240 machine gun  110  of  FIG. 2 . 
     Referring now to  FIG. 10 , there is an embodiment of variant of the M240LW machine gun  310  with extended trigger assembly  124 . In this optional embodiment of machine gun  310 , the receiver is identified by numeral  218  and is generally the same as that of M240LW machine gun  210  as provided in  FIG. 8 . Here, extended trigger housing assembly  124  includes proximal leg  150  and attaches to trigger housing engagement  226  via the proximal leg  150 . Furthermore, as provided previously, extended trigger housing assembly  124  includes grip  125  and trigger  132 . Similar to the M240LW as indicated in  FIG. 8 , the receiver is about the same as indicated by numeral  218 . In further optional embodiments, grip  125  may be removable from extended trigger housing assembly  124 . In some other optional embodiments, extended trigger housing assembly  124  may be compatible with grips that will fit a standard AR15/M16 type firearm. Ultimately, grip  125  and trigger  132  are positioned distally forward toward distal end  20  and away from proximal end  22  as occurred with conventional M240 machine guns. 
     Referring now to  FIG. 11 , there is a comparison of the original Barrett M240LW machine gun as designated by numeral  210  with the two previously described embodiments of the new machine guns designated by numeral  310 . This comparison illustration shows the shorter overall length using either the adapter or extended trigger assembly housing which further advantageously provides greater balance to the firearm. 
     Referring now to  FIGS. 12 a  and 12 b   , there is an embodiment of an operating rod assembly for a M240 machine gun as illustrated in  FIG. 1 , the operating rod assembly designated by numeral  52 . Generally, operating rod assembly  52  includes sear engagement  54  on the underside of rear section  56  of operating rod assembly  52 . As trigger housing assembly  24  is located near the proximal end of receiver  18  of the conventional M240 machine gun, trigger housing assembly  24  is appropriately positioned so as to properly position the sear (not shown) to communicate with sear engagement  54  on the underside of rear section  56  of operating rod assembly  52 . 
     Referring now to  FIGS. 13 a  and 13 b   , there is an embodiment of a new operating rod assembly for a new M240 machine gun as described in the present disclosure. For example, for embodiments such as but not limited to those disclosed within  FIG. 2  and  FIG. 9 , operating rod assembly  152  may be utilized. Specifically, operating rod assembly  152  may include forward sear engagement  154  rather than the traditional sear engagement  54  as located on the underside of rear section  56 . As such, forward sear engagement  154  is positioned to interact with the sear per the forward position of trigger housing assembly  24 .  FIG. 16  provides a cross-sectional view illustrating operating rod assembly  152  with sear engagement  154  engaging the sear of the M240 machine gun. More specifically, in optional embodiments, sear  155  can engage sear engagement  154  in a more distal location on operating rod assembly  152  in comparison to prior art M240 machine guns. Generally, with the new operating rod assembly  152 , the sear surface and ramp surface is located greater than two inches distally toward the muzzle when compared to the prior art operating rod assembly as depicted in  FIGS. 12 a  and 12 b   . In some optional embodiments, the sear engagement is moved about 3.3 inches closer distally toward the muzzle in comparison. 
     Referring now to  FIGS. 14 a  and 14 b   , there is an embodiment of a rear sight that may be used with a M240 machine gun, the rear sight designated by the numeral  58 . In optional embodiments, rear sight  58  may be attached to the upper receiver of M240 machine gun  10  as illustrated in  FIG. 1 . Additionally, other various embodiments of a rear sight may be used such as those for the M240LW as illustrated in  FIG. 8 . However, in some optional embodiments, a user may find it useful to have an area for a check rest on the receiver wherein the butt stock is shortened, for example in  FIGS. 3, 5, 9, and 10 . One embodiment of such receiver cheek rest is illustrated in  FIGS. 15 a  and 15 b    and indicated by numeral  60 . Such embodiment may provide a comfortable position for a user especially where the trigger housing assembly is in the forward position thereby causing the receiver of the firearm to be in a more rearward position toward the user&#39;s shoulder and face. In embodiments of the M240LW wherein unitary shells are utilized, optional embodiments of the cheek rest can be added to the shells upon formation of the receiver, or optionally, the cheek rest may be formed from the union of the shells. 
     Referring now to  FIGS. 17-19 , there are illustrations of top cover  362 . Top cover  362 , in optional embodiments may be understood to be a top cover with an auxiliary Picatinny rail with an embedded rear sight. Generally, top cover  362  relocates the rear sight and incorporates it toward the rear of Picatinny section  364  so that the rear sight is ergonomically in a favorable position. In comparison to the prior art, the rear sigh is moved distally forward so it will not disturb the cheek weld of the user.  FIG. 17  illustrates the rear sight in the lower position while  FIG. 18  depicts the rear sight in a raised position to illustrate how it may be used and adjusted for distance elevation.  FIG. 19  illustrates top cover  362  in place on an optional embodiment of a 240LW machine gun. As one can see, the rear sight of top cover  362  is moved distally forward thus providing space for a cheek weld for a user. 
     Furthermore as used herein, shortened butt stock  112  is often shown with various embodiments of the invention. Such is not mean to be limiting, but rather illustrate one possible embodiment of a shortened butt stock. In some optional embodiments, the shortened butt stock is shortened to a length just to contain the hydraulic buffer system. In yet other optional embodiments, a collapsible stock may be used with the firearm. Even with differing types of stocks being used with optional embodiments of the M240 machine gun, the trigger housing assembly may still be positioned in a forward position to provide for greater ease in using such firearm. 
     As such, the adapters or extended trigger assemblies in various embodiments allow for the use of a shorter butt stock on an M240 machine gun, including the M240LW machine gun, as the grip and trigger are moved distally forward. Additionally, new M240 machine guns may be manufactured per the embodiments described herein. Thus, significant weight savings may be realized as well as better balance and usability of the weapon platform. As a shorter butt stock can be used with the grip placed distally forward, a user may be able to maneuver the machine gun in an improved fashion. 
     As used herein, “forward position” refers to a position located more distally than the prior art M240 machine gun as illustrated in  FIG. 1 , for example. Some may understand this to mean the trigger housing assembly is located about adjacent to the ejection port or alternatively at about the central area of the main portion of the receiver. In some further optional embodiments, the trigger housing assembly may be moved distally on the receiver so that it is at least about two inches from the proximal end of the receiver. 
     Various accessories may also is be used with embodiments of the machine gun as described herein, including both a handguard and a mount. As disclosed in  FIGS. 20 through 32 , handguard  250  and/or bipod  262  can be used with either of the previously disclosed receivers manufactured by Barrett Firearms Manufacturing, such receivers being previously designated with the numerals  218  and  318 . For purposes of clarity of this disclosure, handguard  250  is describe in relation to receiver  218  and machine gun  210  though may be used with receiver  318  and machine gun  310  or other variants. Furthermore, it is understood that other receiver designs may work similarly with optional embodiments of handguard  250 . Thus, as used herein, handguard  250  has distal end  252  and proximal end  254  and may attach to attaches to receiver  218  of machine gun  210 . Optionally, bipod  262  may attach to handguard  250  so as to provide support to a user. 
     Generally bipod  262  may include first leg  264  and second leg  266  attached to main bipod body  268  as illustrated in  FIG. 21 , the bipod legs  264  and  266  being rotatably connected to bipod body  268  so that the user may orient the bipod legs into the orientation the user may such desire. Thus, as illustrated in  FIG. 20 , bipod legs  264  and  266  may be oriented in a downward position to provide support when firing the machine gun  210  or alternatively may be folded or rotated in a variety of orientations to suit the user&#39;s desires. 
     Referring now to  FIG. 22 , there is an illustration of handguard  250  and bipod  262  separate from machine gun  210  with first leg  264  and second leg  266  folded back along the sides of handguard  250 . As used throughout this disclosure, handguard  250  has first handguard side  256 , second handguard side  258  and bottom handguard side  260 . Generally first side  256  is understood to be the left side of the firearm from the point of view of the user when firing the firearm whereas second side  258  is understood to be the right side of the handguard as understood from point of view of the user firing the firearm. Bottom side  260  is generally understood to go about the bottom area of the firearm and thus connect first side  256  and second side  258 . In optional embodiments where handguard  250  includes a design in which the handguard is more circular or oval in shape, generally the left side of the handguard would be understood to be first side  256  whereas the right side of the handguard would be understood to be second side  258  despite the handguard having a generally round design. When bipod  262  is attached to handguard  250 , bipod  262  generally attaches to the distal end  252  of handguard  250 . 
     Referring now to  FIG. 23 , there is a cross-sectional view of handguard  250  with bipod  262  attached. The cross-sectional view is taken through about the middle of bottom side  260  of handguard  250 . Here in  FIG. 23  one can also see interior surface  270  of handguard  250 .  FIG. 23  also includes first side  256  of handguard  250  and illustrates first leg  264  of bipod  262  while providing a view of pintle  274  of bipod body  268  of bipod  262  engaged within pintle mount  276  at distal end  252  of handguard  250 . Through use of pintle  274  on bipod body  268  of bipod  262  that engages pintle mount  276  of handguard  250 , bipod  262  may be removably attachable to handguard  250 . Advantageously, through such engagement, pressure that may be exerted by bipod  262  upon machine gun  210  with handguard  250  is exerted upon handguard  250  rather than the pressure being applied to the gas block of the machine gun. Thus, the use of handguard  250  with bipod  262  may result in less deviation in the direction of fire when using a bipod as handguard  250  engages receiver  218  of machine gun  210  rather than the gas assembly. 
     Referring now to  FIG. 24 , there is an illustration of handguard  250  without bipod  262  and also additionally without machine gun  210 . This illustration provides a view of interior surface  270 , exterior surface  272  as well as pintle mount  276 , proximal handguard end  254 , distal handguard end  252  and second side  258  of handguard  250 . Additionally, interface system  278  is visible and can be seen on both first handguard side  256  and second handguard side  258 . Generally, interface system  278  and optional embodiments may be included on either first side  256 , second side  258  and/or bottom side  260  and may be used to affix accessories to the handguard. Such accessories may vary from lights to grips to laser indicators and the like among other various firearm accessory components. In optional embodiments, interface system  278  may embody a KeyMod style of interface as is illustrated throughout this application. Other interface systems may also be used including the Picatinny style rail style interface, also known as MIL-STD-1913 rail, and other style of mounting systems that are used within the firearm industry. In optional embodiments, interface system  278  may be present on multiple sides of handguard  250  as is illustrated throughout the various figures of this disclosure. Yet in further optional embodiments, interface system  278  may be absent from handguard  250 . Despite having no interface system, handguard  250  could still in optional embodiments provide for connection to a bipod as pintle mount  276  could still be present. In yet further optional embodiments, pintle mount  276  may or may not be present as some uses of machine gun  210  may not require or be designed for use with bipod  262 . 
     Referring now to  FIG. 25 , there is a view of handguard  250  from distal end  252  of handguard  250 . Here one can see pintle mount  276  as well as first handguard side  256 , second handguard side  258  and bottom handguard side  260  as well as exterior surface  272  and interior surface  270 . Additionally from such viewpoint one can also see bosses  280  on interior surface  270  of handguard  250 . Bosses  280  may optionally be present to engage slots  282  on receiver  218  of machine gun  210 . As used herein, boss refers to a raised portion that may generally fit to a corresponding slot or recess. Furthermore as used herein, slot generally refers to a recessed opening, valley, or indentation for which a boss may fit there within. The use of one or more bosses  280  on handguard  250  to correspond to one or more slots  282  on receiver  218  of machine gun  210  provides for a mechanically strong joint. 
     In optional embodiments, two bosses may be included, one on first side  256  of handguard  250  and another boss  280  on the second side  258  of handguard  250 , which both correspond to slots  282  on receiver  218  of handguard  250 . While the general optional embodiments describe two bosses  280 , further embodiments may include a greater or lesser amount of bosses depending upon the specific design of the receiver. In some optional embodiments bosses  280  may be absent with the handguard  250  attaching with other means. 
       FIG. 26  illustrates receiver  218  with a slot  282  that can engage boss  280  on the interior surface  270  of second side  258  of handguard  250 . Additionally visible on  FIG. 26  are mounting points  284  which correspond to attachment point  286  on handguard  250 . As illustrated in some of the subsequent drawings, mounting points  284  of receiver  218  generally align with attachment points  286  of handguard  250  so that handguard  250  may be secured to receiver  218  of machine gun  210 . In yet further optional embodiments, attachment hardware  288  may be used to engage both mounting point  284  and attachment point  286  and thus attach handguard  250  to machine gun  210 . In optional embodiments, attachment hardware  288  may be a variety of different screws including screws having a size of #10-32. In some optional embodiments, attachment hardware may include a variety of different screws including torque screws as well as screws that may be engaged by Allen wrenches, various screwdrivers or the like. 
     As illustrated throughout various figures of the optional embodiment of handguard  250 , three attachment points  286  may be positioned at about proximal end  254  of handguard  250  on both first side  256  of handguard  250  and second side  258  of handguard  250 . In such optional embodiments, receiver  218  may have at least about six mounting points  284  that can correspond to six attachment points  286  of handguard  250 .  FIG. 27  illustrates an optional embodiment of handguard  250  installed on receiver  218  of machine gun  210  with attachment hardware  288  in place. 
       FIGS. 29 and 30  illustrate exploded views to further indicate how one or more bosses  280  of handguard  250  align with one or more slots  282  of receiver  218  as well as how mounting points  284  can correspond with attachment points  286  for attachment hardware  288 . Such illustrations are provided with the barrel removed from machine gun  210  to provide greater clarity in explaining the engagement of handguard  250  to receiver  18 .  FIG. 15  is a cutaway view through a mounting point  284  and attachment point  286  with attachment hardware  288  in place in this optional embodiment. Additionally, through this illustration one can see how bosses  280  of handguard  250  engage slots  282  of receiver  218 . In further optional embodiments lesser or greater numbers of attachment points, mounting points, and/or attachment hardware may be utilized. 
     Now referring to  FIG. 32 , there is an illustration of bipod  262  as discussed earlier. Pintle  274  is positioned on bipod body  268  with first leg  264  and second leg  266  also affixed to bipod body  268 . With bipod  262  removed from handguard  250 , one can see bipod bosses  290  adjacent to pintle  274 . In use, bipod bosses  290  may be used to limit the rotation of bipod  262  relative to handguard  250  when attached to handguard  250 . This may provide for greater stability in operation of machine gun  210 . In yet further optional embodiments, bipod  262  may not include bipod bosses  290  so as to provide for greater rotational freedom if such is desired. Yet in further optional embodiments, lesser or more bosses  290  may be present depending upon the corresponding structure of distal end  252  of handguard  250 . 
     As such, the handguard as described in various optional embodiments provides for greater usability and improvement upon the M240 variant machine guns. As handguard  250  affixes to the receiver of a machine gun, force upon handguard  250  advantageously delivers such force to the receiver as opposed to delivering it to the barrel assembly or gas assembly. Generally, this results in less deviation in the actual impact of shots fired from the machine gun relative to the intended point of aim. Furthermore, the use of interface systems allows for a variety of useful accessories to be used with such a firearm. 
     Further advantages that may be realized are that the barrel may be changed in some optional embodiments without requiring the removal of the handguard. In further optional embodiments not illustrated, the handguard may span across the top of the barrel in addition to spanning below the gas assembly and barrel. 
     Generally, the handguard may be constructed of a variety of different materials. One such option includes the handguard being formed or extruded from various different types of aluminum including 5000, 6000, or 7,000 series aluminum which may optionally include, without limitation, tempered aluminum alloys, examples of which may be 6061-T6, 7075-T651, or 7050-T7651. In further optional embodiments, other materials may be utilized which can include different types of heat treatable alloys or stainless steels such as 17-4PH. In other embodiments, the handguard could be formed from a weldment or cast or alternatively from various alloys ranging from magnesium to titanium alloy or possibly even composite materials. 
     This written description uses examples to disclose the invention and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims. 
     It will be understood that the particular embodiments described herein are shown by way of illustration and not as limitations of the invention. The principal features of this invention may be employed in various embodiments without departing from the scope of the invention. Those of ordinary skill in the art will recognize numerous equivalents to the specific procedures described herein. Such equivalents are considered to be within the scope of this invention and are covered by the claims. 
     All of the products and/or methods disclosed and claimed herein may be made and/or executed without undue experimentation in light of the present disclosure. While the products and methods of this invention have been described in terms of the embodiments included herein, it will be apparent to those of ordinary skill in the art that variations may be applied to the products and/or methods and in the steps or in the sequence of steps of the method described herein without departing from the concept, spirit, and scope of the invention. All such similar substitutes and modifications apparent to those skilled in the art are deemed to be within the spirit, scope, and concept of the invention as defined by the appended claims. Thus, although there have been described particular embodiments of the present invention of a new and useful Firearm System, it is not intended that such references be construed as limitations upon the scope of this invention except as set forth in the following claims.