Rifle Conversion Devices and Method

This application is a continuation of and claims benefits of priority under 35 U.S.C. § 120 to U.S. application Ser. No. 17/061,481, filed on Oct. 1, 2020, the complete contents of which application is incorporated herein by reference.

The present invention relates to the field of firearms, and more particularly to methods and devices for converting an automatic style of rifle to achieve the form and benefits of a bolt-action style rifle but with auto-loading rates of fire and common automatic rifle parts.

It is common for high-power automatic rifles to be utilized by law-enforcement, military and competitive shooters. An example of a high-power tactical rifle is the AR-15 platform. There are a number of different tactical rifles on the market, including those that are modified. One difference between a tactical rifle and other sport rifles is that the tactical rifle utilizes a pistol style grip in addition to a forward hand grip and buttstock. The AR-15 rifle system or style system, includes a number of derivatives, examples of which include the AR-10 which is provided in 0.308 caliber, the M-4, as well as other variants. An AR-15 rifle platform typically comprises a lower receiver, a trigger group located in the lower receiver, an upper receiver, a handguard, a pistol grip and a buttstock. The main structural components are the upper and lower receiver elements. The external components include the handguard, pistol grip and the buttstock which attach to the lower receiver and upper receiver, with the pistol grip and buttstock attaching to the lower receiver and the handguard attaching to the upper receiver. The handguard typically encircles the barrel of the rifle. The trigger group or trigger assembly is housed within the lower receiver. There are a number of aftermarket triggers that may be placed within the trigger housing of the lower receiver. Because of the typical design of the automatic rifles, most rifle users consider the rifles to have a handguard, pistol grip and buttstock. In many instances one of the most widely used accessories for attachment to a rifle is a sight or other form of an optic or sighting system. In some instances the sight may include a laser. A laser sight is used which projects a narrowly focused beam of light that is visible on an intended target. Some sights utilize magnifying objectives to maximize performance of the rifle. There are some optical sights that utilize telescopic finders, such as advanced optical combat gunsights (acog's) which attach to an upper receiver.

The AR-15 rifle is different than its predecessor breech-loading rifles, which typically had a single receiver housing both the trigger and reloading mechanism. The AR-15 provides a distinguishing feature of modular construction in order to facilitate the substitution of parts making repairs easier for military rifles. In an AR rifle arrangement, the lower receiver typically includes the trigger guard that is situated ahead of a detachable pistol grip, and behind the magazine well that is designed to receive and hold detachable ammunition magazines. The typical AR rifle lower receiver provides an attachment point for the buttstock and holds the trigger assembly. The trigger assembly includes the hammer. The lower receiver is attached to an upper receiver and may be removably decoupled for cleaning or repair of malfunctions. The AR style rifle upper receiver contains the bolt carrier assembly and is attached to the barrel assembly. Sights are attached to the upper receiver or the barrel assembly. A handguard usually is attached to the upper receiver, and, in some instances, may be attached to the barrel. The handguard functions to enclose the barrel and a gas-operated reloading device. Burnt powder gas is vented from an opening in the barrel near the forward end of the handguard.

There are a couple of styles of AR-15 type rifles. Some AR-15 rifles have been constructed using a direct gas impingement system (DGI), while others are configured using a short-stroke gas piston design. With the DGI style, a tube vents burnt powder gas back into the bolt carrier assembly. The gas expands within the variable volume chamber to force the bolt open. That action ejects the spent cartridge case. The bolt is then closed by the action of a buffer spring, typically located within the buttstock, which pushes the bolt closed and picks up a new cartridge from the magazine. The DGI system is designed to release the unburned smokeless powder residue to minimize the tendency for malfunctions. The other style, which employs a short-stroke gas piston, involves a metal rod that pushes against the bolt carrier. The metal rod is driven by a piston, which typically is situated behind the barrel gas port.

There are a number of styles of AR rifles, which may include a detachable magazine, a pistol grip, as well as folding or collapsible stocks that reduce the overall length of the rifle. An example of a handguard mounting device for an AR style rifle is disclosed in U.S. Pat. No. 7,716,865 entitled, “Systems and Methods for Providing a Hand Guard and Accessory Mounting Device for a Firearm”. The '865 patent discloses a handguard and a mountable accessory that connects to threads provided on the barrel. The '865 patent also discloses set screws used for securing the accessory along the barrel. U.S. Pat. No. 8,931,197 discloses a “Handguard for Firearm” with a barrel that is free-floating and is supported by the receiver assembly. The forearm is connected to the barrel or receiver assembly and is provided with rails for receiving accessories thereon. A conversion for a rifle, such as an AR-15, is disclosed in US 2012/0291329 for “Rimfire Action Platform Conversion” and discloses a handguard mount provided on the main stock for attaching a handguard thereto. US 2016/0209136, entitled, “Convertible Lower Receiver”, provides a device for changing rounds, which is designed to allow a user to configure from one round to another by allowing switching from one upper receiver to another. U.S. Pat. No. 7,640,689 discloses a “Hand Guard System For Use With A Firearm” that comprises a first support or holding unit and a second support or holding unit, each of which removably couples to a firearm to support a handguard shell therebetween without having to remove or disassemble a barrel of the firearm to remove the holding units. The barrel may be used as a mounting surface to attach a base member. US 2010/0186278 discloses a “Handguard Assembly and Stanag Mount Adapter Assembly,” with a securing mechanism for attaching a handguard to the barrel nut. US patent application 2019/0178608 A1 for a “Firearm Chassis With Integrated Rail System”, discloses a chassis for a firearm that includes a lower receiver and a lower forend that are monolithically formed with one another.

US patent application 2013/0014418 A1 for a “Detachable Chassis Base For Rifle” discloses a lower chassis receiver assembly with a detachable chassis base that can be completely removable, or hingedly attached to provide access without completely removing the chassis base in order to handle different magazines and to permit removal of the chassis base for cleaning of the trigger mechanism. U.S. Pat. No. 10,443,963, discloses a “Modified Rifle Lower Receiver, Related Components, Cartridges, and Methods” that includes removing the standard lower receiver and firing pin from an upper receiver, installing a longer, modified firing pin into the upper receiver, and installing the modified lower receiver on the upper receiver.

US 2015/0184976 “Firearm Having a Removable Hand Guard” discloses a rifle having a receiver with a receiver frame, a barrel removably connected to the receiver frame, a cover coupled to the barrel and a removable handguard section extending over and surrounding the barrel. A “Firearm Accessory Mounting System” is disclosed in US2009/0056191 which has a handguard surrounding a portion of the barrel, and an upper shell and lower shell. A modular receiver system is disclosed in U.S. Pat. No. 7,313,883 comprising a barrel and receiver assembly providing a quick changeover coupling means for connecting the barrel to the receiver.

On rifles that have mating upper and lower receiver assemblies, there exists tolerance stack-up, or “slop” that will allow small movements between the two receivers when firing the rifle. These movements impact accuracy and precision, especially at extended ranges. Accuracy and precision are impacted due to angular projections of the movement between the receivers. Therefore, as the shooter attempts shots at longer ranges, the error from receiver movement is magnified.

Attempts to mitigate the tolerance slop however still have contact from the user on the upper receiver causing movement between the receivers. No matter what device is used between the receivers to mitigate tolerance stack-up, there will always be some movement allowed between the receivers due to every physical part having an associated tolerance. When the operator fires the rifle, his or her off-hand remains in contact with the handguard, grip, or other parts connected to the upper receiver that will force movement between receivers.

In addition to receiver tolerance differences, the traditional free float handguard can bend slightly based on material composition and length. If the sights or laser accessories are attached to that handguard, they will be subject to the movement from bending and decrease accuracy.

A need exists for a method and device that can provide versatility to the existing AR type rifles and improve accuracy.

Devices and methods for implementing a conversion of an automatic type rifle are provided. The devices and methods provide a chassis conversion for autoloading rifles with upper and lower receiver subassemblies.

A chassis conversion is provided for automatic type rifles, including AR-15, AR-10, and combat assault style rifles, such as special operations combat assault type rifles (also sold and/or referred to as SCAR-type rifles, and/or SCAR rifles when used by FN Herstal, S.A. for its brand of rifles), and CZ Bren rifles (CZUB). The chassis being implemented is similar to that of traditional bolt action platforms but is instead intended for AR-15 style rifles and similar variations including, but not limited to, the M16 and its sub-variations, the M4 and its sub-variations, the DPMS LR-308 and its sub-variations, the FN-SCAR, the Bushmaster ACR, the Smith & Wesson M&P 10, CZ Bren and the like. The design is also applicable to the SCAR pattern of rifles. The chassis conversion may be implemented for a variety of different caliber/chambering rifles.

The conversion device and methods provide a chassis style rifle configuration for automatic type or style rifles, including AR-15/AR-10/SCAR pattern rifles, comprising a conversion component that attaches to a standard or modified standard lower receiver while allowing the rifle to remain capable of being used as either a chassis gun or standard rifle configuration under different circumstances, as the operator desires.

The device eliminates the need for the operator to contact the upper receiver assembly during firing except to work firing controls when necessary (e.g., when the lower receiver component, such as a trigger or other firing control component, engages with an action component of the upper receiver). By eliminating the need to contact the upper receiver during the act of firing a shot, particularly for gripping with the off-hand or having a hand resting on separate shooting accessories, the rifle's accuracy and precision are enhanced. Accuracy and precision are enhanced by eliminating movement that would normally be caused by gripping the forearm of the rifle causing movement between the upper receiver and lower receiver assemblies or flexion of the handguard.

According to some embodiments, the devices may be adapted and configured to convert mostly any AR-15/AR-10/SCAR style derivation or rifle that uses separated lower and upper receiver assemblies by providing a lower receiver extension to form a rifle forearm.

The devices and methods provide the AR/SCAR styles of rifles with a configurable and deconfigurable capability of achieving a form similar to that of a bolt action rifle but with auto-loading rates of fire and common AR parts. The present method for converting the automatic type rifles involves configuring the rifle with one or more conversion parts, referred to in some embodiments herein as a mount piece. The conversion devices are fitted to the automatic rifle, such as an AR style rifle. The devices may comprise a mount piece that connects to the rifle. The mount piece may comprise a plurality of elements that enable connection of the mount piece to the rifle, and more preferably, the magazine well or other portions of the lower receiver of the rifle. The present devices and methods minimize, and more preferably eliminate the need to handle the upper receiver or components attached to the upper receiver, allowing for improved accuracy.

The seam of an AR style rifle (or other style rifle having a receiver assembly that is comprised of an upper receiver and lower receiver) where the upper and lower receivers meet generally provides an area where machining tolerance stack-up, or “slop”, is present and allows small movements between the two mating parts. When a user touches any parts connected to the upper receiver (barrel, handguard, etc.), the user is causing small movements of the upper receiver relative to the lower. In the case of rifles equipped with free float handguards, the pressure on the handguard by the user causes flexion of the handguard creating similar small movements. The small movements accentuate reduction of accuracy, especially when firing from long ranges. The present invention provides an AR chassis conversion, which according to preferred embodiments, is constructed to completely free float the entire upper receiver of an AR to the lower receiver. The embodiments eliminate the need to touch any part of the upper receiver or the upper's mating parts when firing the rifle. In other words, even when using a free-float style handguard, there is still a point of contact with the upper receiver when gripping and firing the firearm. The present configuration of the conversion design eliminates that point of contact with the upper receiver by extending the reach of the lower receiver with a forearm originating solely from the lower receiver subassembly. According to preferred embodiments, the conversion may be accomplished with a mount piece that connects to the lower receiver. The mount piece or a component attached to the mount piece, such as a forearm piece, may be integrated as part of the mount piece, or alternatively, may be connectable to the mount piece and released or disconnected therefrom. The detachment of the component, such as a forearm piece, from the mount piece enables the return to the rifle configuration where the mount piece is still connected to the lower receiver. In this configuration, the mount piece may serve to attach and support one or more other components, such as accessories, or a different forearm piece or handguard.

The invention permits ready change of components, such as accessories, to the mount piece. The configuration of the mount piece holds the accessories to the lower receiver, and does not rely on the upper receiver to support the accessories or the mount piece, thereby eliminating user contact with the upper receiver or accessories connected thereto.

According to preferred embodiments, the conversion device is configured to comprise a mount piece that is securable to the magazine-well or other portions of the lower receiver. According to some preferred embodiments, the securable mount piece may extend a new forearm for gripping which may be disposed outward, parallel to the barrel.

According to a preferred implementation, the method for converting the rifle involves the removal of the original handguard to allow the new conversion chassis handguard to remain close to the barrel much like a standard handguard. Then a cover for the gas tube or gas piston assembly is affixed to the upper receiver to protect those parts without the original handguard in place to do so. The cover may incorporate picatinny rail sections to facilitate accessory mounting.

According to preferred embodiments, the conversion chassis is comprised of a mount piece and, preferably also includes a forearm piece. The mount piece attaches to the lower receiver. According to some embodiments, the mount piece may be mounted to the magazine-well. The mount piece provides a mounting structure to which accessories or other mounting components may be attached. According to some preferred embodiments, the mount piece provides a forward extension that is located after the magazine well. The mount piece may be configured to comprise a plurality of portions.

According to some preferred embodiments, the conversion chassis is comprised of a mount piece and forearm piece. According to some embodiments, the mount piece may be comprised of a series of parts that conform to the magazine-well or other portions of the lower receiver. According to some preferred configurations, the mount piece may extend a mounting surface onto the front of the magazine-well when joined together or installed on the magazine well. The surfaces formed by the mount piece subassembly are then used to fasten (e.g., screw or clip) the forearm piece subassembly in place to form the entire conversion chassis assembly.

The present devices and configuration allow the entire upper receiver assembly to remain free floated with respect to the entire lower receiver assembly. For example, accessories such as a bipod (or other accessory) may be mounted to the forearm piece and, as a result of the present conversion configuration and mount, will not apply pressure to the upper receiver in any way. The top cover for the gas tube or gas piston can be affixed to the barrel nut, upper receiver, barrel, gas block, or front sight base to provide a steady base for accessory mounting without touching the forearm piece and compromising accuracy.

The present method and devices provide improved accuracy from the automatic rifle platforms, such as, for example, the AR-15/AR-10/SCAR type platforms, and mimics the accuracy of precision bolt-action rifles. The AR-style of rifle is already an accurate platform, but it is subject to the same tolerance issues present in any machine. The present conversion devices and methods mitigate the issues present in the rifle to provide a more accurate, precise, and stable shooting system. The conversion chassis also prevents the need for permanent modifications to be made to the rifle. The system further allows rapid fire of a chassis-based rifle system compared to the rate of fire achievable with a bolt-action rifle. For example, the invention also provides shooters with the ability to quickly transform and reconfigure a carbine or similar style rifle into a precision platform with the ability to quickly reverse the changes at will. The conversion system also allows for a user to have a more traditional style of forearm, if the user prefers. Finally, the conversion system allows users with minimal rifle building skills the ability to install and maintain the conversion by using an automatic rifle, such as the AR-15/AR-10/SCAR, as the base rifle.

Embodiments of the method and devices provide a lower receiver mounting method with a separate, detachable forearm subassembly. The devices and methods of the invention prevent the necessity for any permanent changes to the lower receiver for practicality, reliability, as well as in some instances for legal purposes. From a practicality standpoint, allowing removal minimizes the impact the chassis conversion system has on impeding the natural pivoting motion of the upper receiver during firearm disassembly. For practicality, a nonpermanent option also provides the user the ability to maintain one lower receiver that can provide the benefits of a chassis rifle under some circumstances and a normal rifle configuration under other circumstances. In other words, it allows easy removal to revert back to a non-converted lower receiver at the user's will which makes the same lower receiver serve a variety of roles. The same lower receiver serving as a chassis gun or a standard rifle configuration under different circumstances also allows the serialized part of the firearm to be used in a variety of roles. Therefore, only one serialized part needs to be controlled versus having a dedicated chassis gun and dedicated standard rifle. The ability to meet lawful compliance and provide versatility is accomplished with the invention. Also, the ability to separate the forearm from the mount subassembly allows a variety of different forearm pieces (varying in length, height, width, material, etc.) to be installed onto the same mount subassembly. The ability to install a variety of different forearm pieces allows the user to tailor a forearm piece to his or her individual needs. Additionally, the mount subassembly can then be made for a specific firearm model and a multitude of forearm piece options will mate with the clamp or mount portion.

It is important to mention that the non-permanent mount assembly is only necessary to avoid permanent modification to a standard AR pattern or SCAR pattern lower receiver. And while the non-permanent solution provides the many benefits such as those listed above and is preferable, this invention, in one or more alternate embodiments, is also applicable to lower receivers that are permanently modified to provide a mount for the forearm. The forearm mounting point can be welded, forged, or provided from virtually any manufacturing process. In which case, the lower receiver after modification would become the new “standard” lower receiver as long as the role of being useable in the non-chassis configuration is still possible. This invention of a chassis conversion is to provide the user with a single lower receiver that can be used as a standard (aka traditional) rifle setup or as a chassis gun at will. It does not make the lower receiver strictly a chassis gun regardless of lower receiver modification. This invention is a conversion, not a monolithic AR pattern receiver.

The chassis conversion methods and devices for the AR style rifle is designed to eliminate the need to grip/mount accessories from any parts touching the upper receiver due to the accuracy error imparted from tolerance slop between the upper and lower receivers or traditional free float handguard flexion. The invention enhances the accuracy of the AR-style rifle in many calibers and configurations. This style of rifle is already an accurate platform, but it is subject to the same tolerance issues present in any machine. This invention mitigates the issues present in the rifle to provide a more accurate, precise, and stable shooting system. Additionally, this invention being a chassis style forearm allows the shooter to have a rifle that resembles a bolt action rifle but with the common parts, availability, and rapid rate of fire of the AR family of rifles. The invention also provides shooters with the ability to quickly transform and reconfigure a carbine or similar style rifle into a precision platform with the ability to quickly reverse the changes at will. Finally, the conversion system provides a more traditional style forearm for shooters who prefer such a component.

By providing a forearm attached to the lower receiver and not contacting the upper receiver, a degree of freedom is removed from the system (the rifle). The forearm allows the operator to only touch parts of the lower receiver assembly when shooting. Contacting the upper receiver is now only necessary to work other controls (charging, sight adjustments, scope adjustments, clearing malfunctions, etc.).

While the two receivers are still free to move relative to each other due to tolerance stack-up, they will be free of additional movement caused by operator contact on the upper receiver. The two receivers have a tendency to settle back into what shall be referred to in this document as a “home position.” The home position is where the two assemblies settle back into after a shot from the rifle as long as there is no interference from the operator. This chassis style conversion eliminates the additional interference thereby allowing the rifle receiver assemblies to settle back into the home position to increase accuracy and precision.

These and other advantages may be provided by the devices and methods. Features disclosed in connection with one embodiment may be employed in other embodiments and/or may be combined together with one or more features of other embodiments.

Referring to the drawing figures, the present invention is used in conjunction with a firearm, such as a rifle, and more particularly, to military or tactical style rifles, such as, for example, an AR-15, AR-10, SCAR, M-16, M-4, etc., and the like. For example, the devices of the invention may be applied to convert rifles, such as automatic type rifles, AR-10, AR-15, and SCAR type rifles. The present method implements conversion of an automatic type rifle, such as an AR-10. AR-15, SCAR or other rifle, to provide a chassis style rifle configuration for AR-15/AR-10/SCAR pattern rifles by attaching a conversion component to a standard or modified standard lower receiver while remaining capable of being used as either a chassis gun or standard rifle configuration under different circumstances, as desired by the user. This device configuration eliminates the need for the operator to contact the upper receiver assembly during firing except to work firing controls when necessary (to translate the actuation to an action component). By eliminating the need to contact the upper receiver during the act of firing a shot, particularly for gripping with the off-hand or resting on separate shooting accessories, the rifle's accuracy and precision are enhanced. Accuracy and precision are enhanced by eliminating movement that would normally be caused by gripping the forearm of the rifle causing movement between the upper receiver and lower receiver assemblies or flexion of the handguard. The conversion devices may be employed to convert an AR-15/AR-10/SCAR derivation or rifle that uses separated lower and upper receiver assemblies by using the same principle of providing a lower receiver extension to form a rifle forearm.

According to some embodiments, the mount portion may mount the forearm to the rifle. The mount portion may provide a foundation for the attachment of the forearm (which may be one of a variety of user selected forearms), and/or other accessories. According to some alternate embodiments, the mount, such as a forearm mount, may be a permanent addition (integrally provided) to the lower receiver allowing for attachments and removal of accessories, such as the forearm or handguard, so that only the lower receiver is contacted (aside from an action component engagement by the trigger when firing). The mount portion may be comprised of a clamp around the lower receiver or portion thereof. According to some other embodiments, the mount portion may be comprised of a tap or hole pattern integral to the lower receiver. The mount may be attached to the lower receiver based on operator preference, and according to preferred embodiments, may be removed therefrom. The mount portion can extend beyond the magazine-well to be joined to other portions of the lower receiver such as the trigger guard, grip, buffer tube, etc. The mount portion preferably provides a sole foundation for attaching a forearm to the firearm originating from the lower receiver instead of the upper receiver. The mount subassembly consists of a series of parts that grasp various areas of the rifle's lower receiver including but not limited to the magazine well and trigger guard. The mount subassembly has recesses that conform to the lower receiver to “cup” the lower receiver. Then the mount provides a portion of material that allows the forearm subassembly to be joined to it. According to some embodiments, the mount subassembly may extend beyond the magazine-well to be joined to other portions of the lower receiver such as the trigger guard, grip, buffer tube, etc. The attachment points between mount subassembly and lower receiver subassembly are dependent on operator preference and specific lower receiver geometry. The user may implement the conversion of a rifle when desiring to convert the rifle to receive and accept accessories on the lower receiver only, so as to prevent engagement of the accessories with parts of the rifle (i.e., the upper receiver).

Referring to, a typical rifleof the prior art AR style is depicted. The firearm or riflegenerally includes a receiver assembly, comprising an upper receiverand lower receiver. The rifleis fitted with a buttstockconnected to the rear of the receiver assembly. In the exemplary depiction of the rifle, a barrelis shown connected to the front of the receiver assembly. The rifleincludes a forearm or forestock(which may alternately be referred to as a “handguard” in the art). In the embodiment depicted, the forestock is shown depicted as a gas tube having apertures therein for venting gasses. The receiver assemblytypically houses the firing mechanism as well as some of the other components, e.g., such as a bolt and a charging handle. Typically, the barreland the bolt are located within or supported on the upper receiver, and the firing mechanism and magazine are typically carried by the lower receiver. As illustrated, a magazine wellis shown disposed within the lower receiver, and a triggeris shown disposed within the trigger guard. In the rifle arrangement illustrated, the barrelin the depicted exemplary embodiment is shown configured to connect to the receiver assemblyand is supported by the connection to the receiver assembly, and is typically supported by the upper receiver. In the embodiment illustrated, a muzzleis shown provided at the tip of the barrel. The forearmis shown connected to the barreland/or receiver assembly, and in the exemplary depiction is shown covering a portion of the length of the barrel. The forearmis shown connected at the receiver assembly, and may for example, in the typical AR style rifle use a threaded connection with threading inside the forearmto connect to a matingly threaded connector of the receiver. Alternatively, AR style rifles may be provided where the forearmdoes not completely cover the barrel, and, for example, may cover or be positioned adjacent one or more sides of the barrel. A magazine holder for holding a magazine also may be provided, and the magazine may be inserted into the magazine wellwhere it is received to provide a supply of ammunition to the bolt and firing mechanism (see the magazinein). The firearmmay also include other known components, such as sights, such as the exemplary sight, a handgrip, and/or other components. It is understood that the firearmmay not include one or more of such components in other embodiments.

The devices and methods of the invention may be utilized in conjunction with a firearm, such as the rifledepicted in, as well as other AR and/or SCAR type rifles.

Referring to, schematics depicting a typical lower receiver assembly() and upper receiver assembly() are shown. The assemblies inare typically for a two-piece style rifle, such as the AR style rifle where a lower receiver and an upper receiver are joined to form the rifle. The fire controlsare formed into the lower receiverto form the lower receiver assembly. The upper receiverhouses the action componentsand joins the barrelto form the upper receiver assembly. The upper receiver assemblyand lower receiver assemblyare joined to form the rifle.

depicts a schematic of a standard type rifle chassis, also known as a chassis style rifle or bolt action type rifle, where the components form a rifle. The exemplary depiction of the formation of the rifle, as schematically shown, combines the action components′, the barrel′, the fire controls′ and upper receiver′, which are assembled together into a barreled action. The barreled actionis joined to chassisto form a complete rifle.

Referring to, a schematic depiction of a device and method for converting an automatic type rifle, such as for example, an AR style rifle, is illustrated. A three-step process is depicted for attaching and detaching a conversion component, such as a mount piece, to the lower receiver of a rifle. In, a standard automatic style rifle, represented by the automatic rifle(similar to the automatic rifledepicted inand described herein) is shown configured as an AR style rifle. The rifleis depicted as the host rifle for conversion. In the upper image, the host rifle's lower receiver assemblyremains free of the conversion components. This represents a standard rifle configuration for AR type pattern rifles. The conversion may be implemented when a user desires chassis-like performance, whereupon the user converts the standard rifleto the conversion embodiment rifle′ shown in the middle image of. The conversion component or components of the device, represented generally by the lower mount pieceis shown installed on the rifle, fitted to the lower receiver assembly, to produce the conversion rifle′ (middle image of). When the user desires to change the mount piece to a different mount piece, or for example, to change a mount piece component or portion, such as the mount piece, the user may then convert the rifle back to the original standard formshown in the lower image of the image series of(which is also the first image-prior to conversion). Alternatively, where the mount piece is provided in a plurality of sections or components, for example, where a first mount piece is configured to mount to the lower receiver, and also is configured to connect with one or more removable second mount pieces, then the conversion back to a standard rifle may be fully converted back, by removing the first mount piece of the plurality of mount pieces, as well as the second or other mount pieces connected thereto, or alternatively, by removing only the second or other mount pieces and leaving installed on the lower assembly, the first mount piece so that the second or additional mount pieces (or accessories, such as a handguard/forearm) may be added to the first mount piece that is permitted to remain installed on the rifle (preferably connected to the lower receiver).

The mount pieceshown in, may be configured to accommodate different host rifle lower receiver assembly geometries. For example, the mount piece may be configured to have a mating profile that is matingly associated with the profile or geometry of the rifle lower receiver to be converted. The mating profile or geometry of the mount may be configured for association with one or more surfaces or other structures of the lower receiver. For example, a particular rifle manufacturer may provide a lower receiver geometry in a rifle that differs from the other lower receiver geometries of other rifles on the market (for performance, aesthetics, etc.), or that have been marketed previously. The present system provides a mount that is designed to attach to the particular lower receiver of the rifle to be converted. In some instances, the mount piece may be configured to fit more than one manufacturer's lower receiver. According to some alternate embodiments, the mount may be provided as part of the lower receiver. Differences in the mount piece configuration may be required to accommodate lower receivers, such as for example, AR-15s, AR-10s, SCARs styles of rifles, and, according to some implementations, mount piece configurations for installation to other manufacturer's specific lower receivers and their specific configurations, may require extending one or more portions of the present device conversion components, such as the mount piece or mount pieces, for attachment to one or more other areas of the lower receiver assembly (e.g., such as the stock, buffer tube, grip, and the like). The present device and method provide for ready attachment to and detachment from the host rifle to be converted. The conversion components, such as the mount piece or mount pieces, only contact with the lower receiver assembly. In other words, according to preferred embodiments, the mount piece or pieces, only engage with the lower receiver, and do not contact or engage with the upper receiver or barrel (or preferably, any of the rifle portions other than the lower receiver.

Referring to, depictions of the rifle(shown in), are again shown, but with alternate mount piece assemblies. For example,illustrates the riflewith a mount piece, shown fitted on the lower receiver, and also including a forearm piece, and a rear portionthat is disposed above the trigger guard, and along the lower receivertoward the buttstock. The mounting portionis shown fitted on the magazine well.depicts a mount piecewhich includes a forearm pieceand a mounting portiondisposed on the magazine well(covered in the view).illustrates another alternate embodiment of a mount pieceshown mounted to the lower receiver, where the mountis configured along the profile of the bottom of the trigger guard, and the front portion of the handgrip. The mount rear portionmay have a profile that mates with the surface of the handgrip, such as for example, the handgrip front portion, and, according to some embodiments, the mount rear portionmay be configured to serve as the front of the handgrip, and optionally may have a profile that is configured as a handgrip profile. The mountis shown with a mounting portionattached to the lower receiver, and fitted on the magazine well(covered by the mount). In each of the depictions in, each respective mount piece,,is connected to the lower receiver (e.g.,) and remains free from contact with the upper receiver.

The devices and methods may be implemented in accordance with the above embodiments, and the embodiments depicted in. Referring to, a standard automatic AR type rifleis shown comprising an upper receiver, a lower receiverforming a receiver assembly, a buttstockconnected to the rear of the receiver assembly, and a barrelconnected to the front of the receiver assembly. The rifleis shown having a magazine wellfitted with a magazine cartridgetherein. The rifleincludes a trigger guardand a handgrip. An exemplary embodiment of a present conversion deviceis shown inin an exploded assembly view.depicts an exemplary embodiment of a conversion component comprising a mount piece. The mount pieceis shown in an exploded assembly view inand is shown assembled and installed on the riflein.shows the exploded view of the mount piecein a top perspective view of the riflewith the mount body portions,shown detached on each side of the rifle magazine well. The mount pieceis shown comprising a mount body. The mount body, in accordance with an exemplary embodiment, is configured having a plurality of components, and, in the exemplary embodiment depicted, has a first mount body portionand a second mount body portion. The mount body portions,connect to the lower receiver. The mount body portions,are shown on opposite sides of the magazine well. As illustrated, the mount bodyis secured to the lower receiver, and in the embodiment represented, is installed at the magazine well. A joining pieceis provided to connect the first and second mount body portions,. Fastening means such as the screwsare shown connecting the joining pieceto the mount body portions,.

According to some embodiments, the mount piececomprises or is configured as a first mount piece, and may remain attached to the lower receiver, such as the lower receiverof the rifleshown herein for illustration purposes, so that accessories or other components may be attached to the mount piece. The mount pieceis shown having a connecting portioncomprising connecting flanges,that are inwardly disposed to connect with each other at the front of the magazine well(see). According to preferred embodiments, the front connecting flanges,engage each other to provide a point of connection for a second mount piece, such as a forearm, handguard or other accessory. As illustrated in, a connection is shown provided in the front connecting flanges,, comprising a plurality of apertures,,on the first mount body portion, and a plurality of apertures,,on the second mount body portion. The apertures,,and apertures,,preferably align with each other. The apertures may comprise threaded bores for receipt of matingly threaded screws, or alternatively, for example, screws and mating bushings may be provided to connect through the apertures, e.g., such as matingly threaded bushings or posts. The mount piecesupports detachably connectable accessories thereon. One example of a detachable accessory is a handguard. A variety of handguards, as desired for use by a user, may be installed on and removed from the conversion component, such as the mount piece.

For example, a forearm portion may be reconfigured to suit a variety of user preferences. The forearm portion may be of a variety of sizes or shapes based on operator preference. The forearm may be constructed to partially or fully enclose the gas tube if the operator desires, or a separate gas tube cover may be employed. According to some preferred embodiments, the forearm portion, such as for example, a handguard, may solely provide the gripping surface and extend from the lower receiver mount, such as the removably connectable mount piece (shown installed on the lower receiver).

According to a preferred embodiment, to illustrate the capabilities of the device, the mount pieceis shown assembled in a configuration connected to a second mount piece. The second mount pieceis shown supporting a forearm piece or handguard, although the second mount pieceor other second mount pieces may connect with the mount pieceto removably mount the handguard and/or other accessories that may be used with the rifle, such as scopes, bipods, magazine holders, and the like. The second mount pieceis shown having a mounting portioncomprised of proximal flanges,that are situated to engage the front flanges or connecting flanges,of the mount piece(see). In the embodiment illustrated the respective flanges,are those of the respective mount piece body portions,. According to preferred embodiments the second mount piecepreferably is configured to make a releasable connection with the first mount pieceso that the second mountpiece may be connected to and detached from the riflevia its releasable connection to the first mount piece. The second mount piecemay be connected separately or together with one or more of the first mount pieceand/or accessories, so that the accessory (or accessories) attached thereto (such as the handguard) may be removable or connected to the mount piecewith the second mount piecealready connected or remaining connected.

In the depiction of, the mount-forearm assembly (comprising the mount pieces,and forearm) affixed to a rifle lower receiverwith an upper receiverinstalled. The illustration inand SE demonstrates that the riflecan be gripped without touching the upper receiverthrough the use of the lower-receiver-mounted forearm.illustrate different views of the rifleshown inshown with the mount pieceinstalled, and with the handguard accessoryconnected to the rifle.

Referring to, the mount piece first body portionand second body portionare shown separate from the other components, with the joining pieceshown separately in.

Referring to, the first body portionis shown separate from the other components. The first body portionis shown having a lateral sidewith wallhaving an inner surfaceand an outer surface. A recessis shown provided in the wall, and is recessed from the inner surface. The recessmay be provided to accommodate the profile of a host rifle to which the mount pieceis to be installed. Accordingly, according to embodiments, the mount body portionsandmay include different wall profiles to accommodate the geometry of the host rifle. The first body portionincludes an angled or tapered bottomat the lower edge of the wall. A channelis shown disposed in the flangeand communicating with the recess. The first mount piecehas a front connecting flange. The front flangeis shown projecting outwardly from a front wall portionof the wall. In the exemplary embodiment illustrated, the front flangesof the first body portionand front flangeof the second body portion(see), have a height that is less than the wall height of wall. The flanges,are configured to fit with an accessory or mounting component, such as the second mount piece.shows the second body portionof the mount piece. The second body portionis configured similar to the first body portion, but includes a differently configured recess, and has a slotextending into the wallfrom the rear flange portion. (For example, the rifle configuration shown inillustrates a projectionthat is accommodated by the recesswhen the second mount pieceis installed on the magazine well. The second body portionincludes an angled or tapered bottomat the lower edge of the wall

Referring to, the joining pieceis shown separate from the other components comprising a plate-like bodyhaving a recess which is shown according to a preferred embodiment comprising a concavity or concave portionspanning horizontally across the connector body, and provided on the connector body rear face. The recessprovides clearance for accessing the triggerwhen the joining pieceis installed on a rifle (see). The connector body spanning wallpreferably is set back relative to the front facesthat mate with the mount piece body portion flanges,. The set back spaceis shown, and in the preferred implementations may receive a portion of the lower receiver magazine well therein. The joining pieceis shown having a plurality of counterbores,,,in the connector body.

As shown in, fastening means comprising fasteners, such as the screws, secure the joining pieceto the mount body portions,. The fastening means preferably comprise a suitable fastener for releasably securing the mount piece to the lower receiver. In the embodiment illustrated, the screwsare received in the counterbores,,,of the connector body.