FIREARM RECEIVER WITH INTEGRATED MOUNTING PLATE

Abstract

A firearm lower receiver defines a magazine well, a fire control well, and a trigger guard, where the lower receiver is configured to mate with and attach to an upper receiver. A bottom portion of the lower receiver defines sloped engagement surfaces extending along opposite lateral sides of receiver. In one example, the sloped engagement surfaces are between the trigger guard and the magazine well. In another example, the sloped engagement surfaces are part of a plate that forms the bottom wall of the trigger guard. The sloped engagement surfaces are configured for use with a corresponding clamp or quick-release mounting system.

Description

TECHNICAL FIELD

The present disclosure relates generally to firearms and more particularly to a firearm receiver with an integrated mounting plate.

BACKGROUND

The Arca-Swiss mounting system is commonly used in photography for attaching cameras and lenses to a tripod quickly and securely. The Arca-Swiss Quick Release System is a two-part system that includes a mounting plate that attaches to the camera body, and a clamp on a tripod. Sides of the mounting plate extend upward and inward at an angle of about 45° to define opposite sloping surfaces, or dovetails, configured to be received in the clamp. The plate has a standard overall width of 35 mm. The dovetails typically are at least 1.5 inches in length but can be longer for large lenses and other applications. The plate can be secured with screws to a camera body or lens. Once attached, the plate can be gripped by the clamp, which, when tightened using a locking release, securely engages the plate. The Arca-Swiss mounting system has been popular in the photography field for being able to slide the plate in the clamp without having to dismount the plate from the camera or lens.

SUMMARY

The present disclosure is directed to a firearm receiver with an integrated mounting plate or surfaces simulating such a mounting plate. In one embodiment, a firearm lower receiver defines a magazine well, a fire control well, and a trigger guard, where the lower receiver is configured to mate with and attach to an upper receiver. A bottom portion of the lower receiver defines engagement surfaces that slope laterally outward and extend longitudinally along opposite lateral sides of receiver. In one example, the sloped engagement surfaces are on a bottom portion of the receiver between the trigger guard and the magazine well and extend along the receiver a distance sufficient for engagement by a corresponding clamp, such as about one-half inch or more. In another example, the sloped engagement surfaces are part of a plate that forms the bottom wall of the trigger guard. The sloped engagement surfaces are configured for use with a corresponding clamp or quick-release mounting system, such as one formed according to dimensions of the Arca-Swiss mounting system.

The features and advantages described herein are not all-inclusive and, in particular, many additional features and advantages will be apparent to one of ordinary skill in the art in view of the drawings, specification, and claims. Moreover, it should be noted that the language used in the specification has been selected principally for readability and instructional purposes and not to limit the scope of the disclosed subject matter.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a clamping assembly for use with photography equipment, in accordance with the prior art.

FIG. 2 is a perspective view of a clamping assembly for use with a firearm handguard, in accordance with the prior art.

FIG. 3 is a front perspective view of a firearm receiver that has sloped surfaces of a mounting plate integrally formed as part of the receiver, in accordance with an embodiment of the present disclosure.

FIG. 4 is a rear perspective view of the firearm receiver of FIG. 3.

FIG. 5 is a side view of the firearm receiver of FIG. 3.

FIG. 6 is a cross-sectional view of the firearm receiver as viewed along line A-A shown in FIG. 5, in accordance with an embodiment of the present disclosure.

FIG. 7 is a front perspective view of a firearm receiver having a mounting plate integrally formed as part of the trigger guard, in accordance with another embodiment of the present disclosure.

FIG. 8 is a rear perspective view of the firearm receiver of FIG. 7.

FIG. 9 is a side view of the firearm receiver of FIG. 7.

FIG. 10 is a cross-sectional view of the firearm receiver as viewed along line B-B shown in FIG. 9, in accordance with an embodiment of the present disclosure.

FIG. 11 is a side view showing a firearm with a receiver having an integrated mounting plate or surfaces thereof, in accordance with an embodiment of the present disclosure.

The figures depict various embodiments of the present disclosure for purposes of illustration only. Numerous variations, configurations, and other embodiments will be apparent from the following detailed discussion.

DETAILED DESCRIPTION

Disclosed is a firearm receiver with an integrated mounting plate. In one example embodiment, a firearm lower receiver has a trigger guard, a bottom portion of which is configured as a mounting plate of a quick-disconnect system. In one such embodiment, the trigger guard is shifted rearward compared to the location in traditional lower receivers based on the AR-15 platform in which the trigger guard is immediately rearward of the magazine well and positioned vertically below the portion of the receiver that houses fire control components. This rearward shift of the trigger and trigger guard provides ample space between the trigger guard and magazine well for the sloped engagement surfaces.

In another example embodiment, a firearm lower receiver defines sloped engagement surfaces along lower sides of the receiver between the trigger guard and the magazine well, where the sloped engagement surfaces are configured and dimensioned to function like the corresponding sloped engagement surfaces of a mounting plate for a quick mounting system. For example, the sloped engagement surfaces can be made in accordance with a mounting plate of an existing mounting system, such as the Arca-Swiss quick release system. In other embodiments, the sloped engagement surfaces can be made in accordance with a new or custom-defined mounting system.

Advantageously, a receiver in accordance with the present disclosure eliminates the need for separate components to be mounted to the firearm, thereby reducing complexity and weight. In addition, locating the sloped engagement surfaces rearward of the magazine well provides an improved balance when the firearm is secured to a clamp on a bipod or other structure. The present disclosure is discussed with reference to a lower receiver that is compatible with an upper receiver based on an AR-15 platform; however, concepts of the present disclosure are not so limited and can be applied to other firearms.

A receiver as variously disclosed herein can be a stand-alone component, part of a complete firearm, or part of a firearm subassembly. In some embodiments, the receiver is a lower receiver of an AR-15 or AR-10 type rifle. In some embodiments, the rifle is chambered for 5.56×45 mm, 7.62×39 mm, .350 Legend, 300 BLK, or any other suitable ammunition. Examples of such firearms are the MCX and MCX-R rifles made by Sig Sauer, Inc. Numerous variations and embodiments will be apparent in light of the present disclosure.

OVERVIEW

The Arca-Swiss mounting system is used in the photography field as noted above. FIG. 1 shows a clamping assembly 10 of the prior art, where the assembly is configured for use with photographic equipment. The assembly 10 includes a clamp 11 that can be operated using a screw knob 12, a ¼-turn lever, or other locking mechanism. The clamp 11 can be part of a monopod, bipod, tripod, or gimbal mount assembly, for example. Tightening the screw knob 12 closes the gap between the jaws 13 so that the jaws 13 engage and tighten on the dovetails to securely retain the mounting plate 15 in the clamp 11. Accordingly, an object secured to the mounting plate 15 can be securely retained.

Due to its success in the photography field, the Arca-Swiss mounting system has recently been adapted for use with firearms as a type of quick-disconnect mount. In one example shown in FIG. 2, an assembly 10′ based on the Arca-Swiss system includes a mounting plate 15 that is held in a clamp 11. In this example, the mounting plate 15 can be secured to a rifle handguard or fore-end of a firearm or air gun by using common machine screws or fasteners based on the M-LOK fastening system 16, part of which is shown here. The mounting plate 15 can have various lengths, including a short version that is 3.3 inches in length and a long version that is 10.25 inches in length. As shown in FIG. 2, the jaws 13 have been tightened with a screw knob 12 into engagement with the sloped surfaces 17 of the mounting plate 15.

Existing mounting plates are a separate component that is configured to mount to a rifle handguard or fore-end of a rifle stock. Accordingly, the handguard or fore-end must be configured to receive the mounting hardware, such as screws, that is used to secure the mounting plate. In some instances, the handguard is already equipped with a Picatinny rail along its bottom surface, where adding the Arca-Swiss mounting plate may require modification so that it can be mounted to the Picatinny rail, for example.

Another challenge is that mounting plate attached to the handguard typically results in the firearm's center of gravity being far behind the mounting plate. Thus, the rear end of the firearm will tend to drop down when the firearm is not in the hands of the operator, creating an unsafe rifle position, a need to tighten the pivot where the clamp is located, and/or requiring the operator to maintain a grip on the firearm at all times. Also, when the mounting plate is positioned toward the rear of the handguard and close to the receiver, the clamp or mount that engages the mounting plate is positioned to interfere with installing and removing magazines from the magazine well. Further, attaching a separate plate adds mass to the firearm. Moreover, the added mounting plate increases opportunity for undesired movement due to movement in the assembly, failure, or error.

In light of the foregoing, a need exists for improved solutions to mounting a firearm. The present disclosure addresses this need and others by providing a firearm receiver having an integrated mounting plate. In one example, the mounting plate is part of the trigger guard of a lower receiver. In another example, a firearm lower receiver defines a mounting plate between the trigger guard and the magazine well. Numerous variations and embodiments will be apparent in light of the present disclosure.

Example Embodiments

FIGS. 3 and 4 illustrate front and rear perspective views, respectively, of a firearm lower receiver 100 (or simply “receiver” 100), in accordance with an embodiment of the present disclosure. FIG. 5 illustrates a side view of the receiver 100, and FIG. 6 illustrates a cross-sectional view of the receiver 100 as viewed along line A-A shown in FIG. 5. FIGS. 3-6 are discussed concurrently below.

The receiver 100 is configured as a lower receiver that is adapted to mate with and assemble to an upper receiver for an AR-15 firearm, an upper receiver based on the AR-15 platform, or equivalent. The receiver 100 has a body 101 that defines a magazine well 110 and a fire control well 112 for components of the fire control group, such as the hammer, fire selector, and the like. The body 101 defines various openings 104 for pins, levers, and components that are attached to the receiver 100. A trigger guard 120 is attached to the body 101 rearward of the fire control well 112. An upper end portion 130 is connected to the body 101 generally above the trigger guard 120 and extends above the top surface 102 of the body 101. The upper end potion 130 can receive components of the recoil assembly (not shown) as well as stock and grip components, as will be appreciated.

The receiver 100 defines mounting surfaces 140, 142 on opposite lateral and lower sides of the body 101. Each mounting surface 140, 142 extends laterally outward from the receiver 100 and extends longitudinally forward of the trigger guard 120. For example, each mounting surface 140, 142 extends longitudinally between the trigger guard 120 and the magazine well 110. Each mounting surface 140, 142 extends downward and outward with respect to a median plane 160 of the receiver 100. For example, each mounting surface 140, 142 defines an angle of about 45° with respect to the median plane 160 (or with respect to the outer surface of the receiver 100, which may be parallel to the median plane 160).

Together the sloped mounting surfaces 140, 142 mimic and function like the dovetail mounting surfaces of a mounting plate that is configured to be received in the jaws of a corresponding clamp (e.g., clamp 10′ shown in FIG. 2). In one embodiment, the sloped mounting surfaces 140, 142 are configured according to dimensions of the Arca-Swiss system. For example, each sloped mounting surface 140, 142 extends a length L, defines an angle α with respect to the median plane 160, and defines a maximum overall width W as measured at the lateral extents of the sloped mounting surfaces 140, 142. In some embodiments, length L is at least one-half inch, including 0.75 inch or more, 1.0 in or more, 1.25 inches or more, or at least 1.5 inches. In some embodiments, the angle α is from 30-60°, including 40-50°, 42-48°, 44-46°, about 45°, or some other angle that is suitable for a corresponding clamp. In some embodiments, the overall width W is 1.5 inches. As shown in FIG. 6, for example, each sloped mounting surface 140, 142 starts from a height H above the bottom surface 106, where H is about 0.075 inch. The cross-sectional profile between the dovetail mounting surface 140, 142 and the bottom surface 106 can be rounded, chamfered, square, or faceted, for example.

As shown in the side view of FIG. 5, the sloped mounting surfaces 140, 142 and bottom surface 106 can be inclined relative to the top surface 102 of the receiver 100. In one such embodiment, the sloped mounting surfaces 140, 142 define an angle α2 of 5-10 degrees, such as about 6.5°. In other embodiments, the sloped mounting surfaces 140, 142 can be parallel with the top surface 102 of the receiver 100 or define some other angle α2 as deemed appropriate.

FIG. 6 illustrates a cross-sectional view of the receiver 100 as viewed along line A-A of FIG. 5, in accordance with an embodiment of the present disclosure. A bottom portion of the receiver 100 defines sloped mounting surfaces 140, 142 on opposite sides of the receiver 100, where the sloped mounting surfaces 140, 142 are symmetrical. In one embodiment, each sloped mounting surface 140, 142 defines an angle α of 45°±0.5° with respect to the median plane 160 and the sloped mounting surfaces 140, 142 define a maximum overall width W of 1.5 inches as measured at lateral extents of the sloped mounting surfaces 140, 142. The lower margin 140a, 142a of each sloped mounting surface 140, 142 begins at a first height H1 above the bottom surface 106, where first height H1 is in a range from 0.050 to 0.100 inch, such as about 0.075 inch. The upper margin 140b, 142b of the respective sloped mounting surfaces 140, 142 is vertically above the bottom surface 106 by a second height H2. In some embodiments, the second height H2 is at least 0.19 inch. The fire control well 112 is defined above the trigger guard 120, a front part of which is shown in FIG. 6.

Referring now to FIGS. 7 and 8, front and rear perspective views, respectively, illustrate a firearm lower receiver 100′ (or simply “receiver” 100′), in accordance with another embodiment of the present disclosure. FIG. 9 illustrates a side view of the receiver 100′, and FIG. 10 illustrates a cross-sectional view of the receiver 100′ as viewed along line B-B shown in FIG. 9. FIGS. 7-10 are discussed concurrently below.

The receiver 100′ is configured as a lower receiver that is adapted to mate with and assemble to an upper receiver for an AR-15-type firearm or equivalent. The receiver 100′ is similar to traditional lower receiver of the AR-15 platform but differs in particular in the construction of the trigger guard 140. The receiver 100′ has a body 101 that defines a magazine well 110 and a fire control well 112 for components of the fire control group, such as the hammer, fire selector, and the like. In this example, the trigger (not shown) would extend below the fire control well 112 and be positioned rearward of the magazine well 110. The body 101 defines various openings 104 for pins, levers, and components that are attached to the receiver 100′. A trigger guard 120 is positioned below the fire control well 112 and connects between the magazine well 110 and the body 101 adjacent an upper end portion 130. The upper end portion 130 is connected to the body 101 at a position that is rearward of the fire control well 112 and extends above the top surface 102 of the body 101. The upper end potion 130 can receive stock components and components of the recoil assembly and buffer components (not shown), as will be appreciated. A mounting block 150 is between the body 101 and rear part of the trigger guard 120. The mounting block 150 is configured for attaching a pistol grip of a traditional AR-15 type firearm. Thus, the receiver 100′ is compatible with many or all existing components used with a lower receiver of a traditional AR-15 type firearm, such as a pistol grip, components of the fire control assembly, and magazines.

The receiver 100′ defines sloped mounting surfaces 140, 142 on opposite lateral and lower sides of the body 101 between the trigger guard 120 and the magazine well 110. Together, the sloped mounting surfaces 140, 142 mimic and function like the dovetail mounting surfaces of a mounting plate that is configured to be received in the jaws of a corresponding clamp (shown, e.g., in FIG. 2). In one embodiment, the sloped mounting surfaces 140, 142 are configured according to dimensions of the Arca-Swiss system. For example, each sloped mounting surface 140, 142 extends a length L, defines an angle α with respect to a bottom surface 106, and defines a maximum overall width W as measured at the bottom of the sloped mounting surfaces 140, 142. In some embodiments, length L is at least one-half inch, including 0.75 inch or more, 1.0 in or more, 1.25 inches or more, or at least 1.5 inches. In some embodiments, the angle α is from 30-60°, including 40-50°, 42-48°, 44-46°, about 45°, or some other angle that is suitable for a corresponding clamp. As shown in FIG. 10, for example, each sloped mounting surface 140, 142 defines an angle α of 45°±0.5° with respect to a bottom surface 106 and the sloped mounting surfaces 140, 142 define a maximum overall width W of 1.5 inches as measured at the lower margin of the sloped mounting surfaces 140, 142. In other embodiments, the angle α can be in a range from 42-48°, in a range from 40-50°, in a range from 30-60°, or some other angle that is suitable for a corresponding clamp. As shown in FIG. 10, for example, the lower margin of each sloped mounting surface 140, 142 starts at a height H above the bottom surface 106, where H is about 0.075 inch. The cross-sectional profile between the dovetail mounting surface 140, 142 and the bottom surface 106 can be rounded, chamfered, square, or faceted, for example.

As shown in the side view of FIG. 9, the sloped mounting surfaces 140, 142 and bottom surface 106 can be inclined relative to the top surface 102 of the receiver 100′. In one such embodiment, the sloped mounting surfaces 140, 142 define an angle α2 of 5-10 degrees, such as about 6.5°. In other embodiments, the sloped mounting surfaces 140, 142 can be parallel with the top surface 102 of the receiver 100 or define some other angle α2 as deemed appropriate.

FIG. 10 illustrates a cross-sectional view of the receiver 100′ as viewed along line B-B of FIG. 9, in accordance with an embodiment of the present disclosure. A bottom of the trigger guard 120 defines sloped mounting surfaces 140, 142 on opposite sides, where the sloped mounting surfaces 140, 142 are symmetrical. In one embodiment, each sloped mounting surface 140, 142 defines an angle α of 45°±0.5° with respect to the bottom surface 106 of the trigger guard 102 and the sloped mounting surfaces 140, 142 define a maximum overall width W of 1.5 inches as measured at the lower margin 140a, 142a of the respective sloped mounting surfaces 140, 142. The lower margin 140a, 142a of each sloped mounting surface 140, 142 begins at a first height H1 above the bottom surface 106 of the trigger guard 120, where first height H1 is in a range from 0.050 to 0.100 inch, such as about 0.075 inch. The upper margin 140b, 142b of the respective sloped mounting surfaces 140, 142 is vertically above the bottom surface 106 by a second height H2. In some embodiments, the second height H2 is at least 0.19 inch. The fire control well 112 is defined above the trigger guard 120, a front part of which is shown.

FIG. 11 is a side view showing a firearm 200 with a lower receiver 100 having an integrated mounting plate or surfaces thereof, in accordance with an embodiment of the present disclosure. The firearm 200 includes an upper receiver 210 assembled to the lower receiver 100. The upper receiver 210 includes a barrel assembly 215. The lower receiver 100 houses components of the fire control assembly. A stock 220 is attached to the upper end portion 130 of the receiver 100. In this example, the stock 220 is configured as a fixed stock similar to a fixed stock found on traditional bolt-action rifles and M16 rifles. In this example, the center of mass CG is located longitudinally between the trigger guard 120 and the magazine well 110, and vertically between the lower receiver 100 and upper receiver 210. The center of mass CG is vertically above the sloped engagement surfaces 140, 142, thereby providing improved balance of the firearm 200 when secured in a mount.

In use, a lower receiver 100, 100′ of the present disclosure can be mounted in and removed from a clamp or other mount that is configured to engage the sloped mounting surfaces 140, 142, such as a clamp 11 configured in accordance with the Arca-Swiss mounting system. For example, a firearm 200 utilizing the receiver 100, 100′ can be clamped to a bipod, a firearm mount on a vehicle, or other structure. As needed, the operator may disengage the clamp to quickly remove the firearm 200, then return the firearm to its clamped position.

Further Example Embodiments

The following examples pertain to further embodiments, from which numerous permutations and configurations will be apparent.

Example 1 is a firearm receiver having a lower receiver defining a magazine well, a fire control well, and a trigger guard, the lower receiver configured to mate with and attach to an upper receiver. A bottom portion of the lower receiver defines engagement surfaces extending laterally outward and extending longitudinally with a length of at least one inch along opposite lateral sides of the bottom portion between the trigger guard and the magazine well.

Example 2 includes the firearm receiver of Example 1, where the length of the sloped engagement surfaces is at least 0.5 inch. In other examples the length is at least 0.75 inch, at least 1.0 inch, or at least 1.5 inches.

Example 3 includes the firearm receiver of any one of Examples 1 or 2, where the sloped engagement surfaces each define an angle from 40°-50°, such an angle of 44-46°, with respect to a corresponding bottom surface of the bottom portion.

Example 4 includes the firearm receiver of Example 3, where the angle is 45°±0.5°.

Example 5 includes the firearm receiver of any one of Examples 1-4, where a lower margin of each of the sloped engagement surfaces is spaced above a bottom surface of the bottom portion.

Example 6 includes the firearm receiver of Example 5, where the lower margin is spaced by at least 0.05 inch above the bottom surface.

Example 7 includes the firearm receiver of any one of Examples 1-6, where the bottom portion has a lateral dimension of 1.5 inches as measured at respective lower margins of the sloped engagement surfaces.

Example 8 includes the firearm receiver of any one of Examples 1-7, where the sloped engagement surfaces are inclined at an angle from 0-10 degrees, such as 4-10 degrees, with respect to a top surface of the fire control well.

Example 9 includes the firearm receiver of any one of Examples 1-7, where lower margins of the sloped engagement surfaces extend in parallel to a top surface of the fire control well.

Example 10 includes the firearm receiver of any one of Examples 1-9, where each sloped engagement surface extends to an upper margin that is at least 0.19 inches above the bottom surface of the bottom portion.

Example 11 is a firearm receiver having a lower receiver defining a magazine well, a trigger well, and a trigger guard positioned below the trigger well, where the lower receiver is configured to mate with and attach to an upper receiver. The trigger guard has a bottom wall that defines sloped engagement surfaces along opposite lateral sides of the bottom wall, the bottom wall having a lateral width of 1.5 inches as measured at respective lower margins of the sloped engagement surfaces.

Example 12 includes the firearm receiver of Example 11, where the sloped engagement surfaces each have a length of at least one inch along the trigger guard.

Example 13 includes the firearm receiver of any one of Examples 11 or 12, where the sloped engagement surfaces each define an angle from 40°-50°, such as 44-46°, with respect to a bottom surface of the trigger guard.

Example 14 includes the firearm receiver of Example 13, where the angle is 45°±0.5°.

Example 15 includes the firearm receiver of any one of Examples 11-14, where the lower margin of each of the sloped engagement surfaces is spaced from a bottom surface of the trigger guard.

Example 16 includes the firearm receiver of Example 15, where the lower margin is spaced by at least 0.05 inch from the bottom surface of the trigger guard.

Example 17 includes the firearm receiver of any one of Examples 11-14, where a lower margin of each of the sloped engagement surfaces is coincident with the bottom surface of the trigger guard.

Example 18 includes the firearm receiver of any one of Examples 11-17, where the bottom surface of the trigger guard is inclined at an angle from 0-10°, such as 4-10°, with respect to a top surface of the fire control well.

Example 19 includes the firearm receiver of any one of Examples 11-17, where the bottom surface of the trigger guard is parallel to a top surface of the fire control well.

Example 20 includes the firearm receiver of any one of Examples 11-19, where each sloped mounting surface extends to an upper margin that is at least 0.19 inches above the bottom surface of the trigger guard.

Example 21 includes the firearm receiver of any one of Examples 1-20, where the lower receiver is compatible with an upper receiver of an AR-15-type rifle.

Example 22 is a firearm comprising the firearm receiver of any one of Examples 1-21.

Example 23 includes the firearm of Example 22, where the firearm is chambered for 5.56×45 mm, 7.62×39 mm, .350 Legend, or 300 BLK ammunition.

Example 24 includes the firearm receiver of any one of Examples 1-21 or the firearm of any one of Examples 22-23, where the sloped engagement surfaces are sized and spaced for use with an Arca-Swiss clamp.

The foregoing description of example embodiments has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the present disclosure to the precise forms disclosed. Many modifications and variations are possible in light of this disclosure. It is intended that the scope of the present disclosure be limited not by this detailed description, but rather by the claims appended hereto. Future-filed applications claiming priority to this application may claim the disclosed subject matter in a different manner and generally may include any set of one or more limitations as variously disclosed or otherwise demonstrated herein.

Claims

1. A firearm receiver comprising: a lower receiver defining a magazine well, a fire control well, and a trigger guard, the lower receiver configured to mate with and attach to an upper receiver;wherein a bottom portion of the lower receiver defines engagement surfaces that protrude laterally outward and extend forward of the trigger guard.

2. The firearm receiver of claim 1, wherein each of the engagement surfaces has a length of at least one-half inch along opposite lateral sides of the bottom portion of the lower receiver.

3. The firearm receiver of claim 2, wherein each of the engagement surfaces is between the trigger guard and the magazine well.

4. The firearm receiver of claim 1, wherein each of the engagement surfaces is sloped downward.

5. The firearm receiver of claim 4, wherein each of the engagement surfaces slopes downward at an angle from 40°-50° with respect to a median plane of the lower receiver.

6. The firearm receiver of claim 1, wherein the bottom portion has a lateral dimension of 1.5 inches as measured at lateral extents of the engagement surfaces.

7. The firearm receiver of claim 1, wherein each of the engagement surfaces is inclined at an angle from 4-10 degrees with respect to a top surface of the fire control well.

8. The firearm receiver of claim 1, wherein a lower margin of each of the engagement surfaces is parallel to a top surface of the fire control well.

9. The firearm receiver of claim 1, wherein each engagement surface extends to an upper margin that is at least 0.19 inches above the bottom surface of the bottom portion.

10. The firearm receiver of claim 9, wherein an outer margin of each of the engagement surfaces is spaced above a bottom surface of the bottom portion of the lower receiver.

11. A firearm receiver comprising: a lower receiver defining a magazine well, a trigger well, and a trigger guard positioned below the trigger well, the lower receiver configured to mate with and attach to an upper receiver;wherein the trigger guard has a bottom wall that defines sloped engagement surfaces along opposite lateral sides of the bottom wall, the bottom wall having a lateral width of 1.5 inches as measured at respective lower margins of the sloped engagement surfaces.

12. The firearm receiver of claim 11, wherein the sloped engagement surfaces each have a length of at least one-half inch along the trigger guard.

13. The firearm receiver of claim 11, wherein each of the sloped engagement surfaces defines an angle from 40°-50° with respect to a bottom surface of the trigger guard.

14. The firearm receiver of claim 13, wherein the angle is from 44 to 46°.

15. The firearm receiver of claim 11, wherein an outer margin of each of the sloped engagement surfaces is spaced from a bottom surface of the trigger guard.

16. The firearm receiver of claim 11, wherein an outer margin of each of the sloped engagement surfaces is coincident with the bottom surface of the trigger guard.

17. The firearm receiver of claim 11, wherein the bottom surface of the trigger guard is inclined at an angle from 4-10° with respect to a top surface of the fire control well.

18. The firearm receiver of claim 11, wherein the bottom surface of the trigger guard is parallel to a top surface of the fire control well.

19. The firearm receiver of claim 11, wherein the lower receiver is compatible with an upper receiver of an AR-15-type rifle.

20. A firearm comprising the firearm receiver of claim 1.