FIREARM MAGAZINE FOR HIGH BALLISTIC COEFFICIENT CARTRIDGES

Abstract

A firearm magazine with an anti-tilt follower assembly housed within a magazine body is provided. The magazine includes a lock plate; a floor plate; a spring; one or more ribs within the magazine body, and one or more channels within the magazine body that have a consistent profile along their length. In some embodiments, the outer front and rear ends of the magazine body are angled forward relative to a magazine well of a firearm. In many embodiments, the anti-tilt follower assembly comprises a front tine and a rear tine, each tine having a curvature to substantially correspond with curvature of an inside of the magazine body. A method of molding a polymer follower for a firearm is also provided, which includes injecting a liquid polymer into the mold between the mold core and the mold cavity uses a side-to-side tooling split for the injection molding process.

Description

CLAIM OF PRIORITY UNDER 35 U.S.C. § 119

The present Application for Patent claims priority to Provisional Application No. 63/439,237, entitled “Firearm Magazine for High Ballistic Coefficient Cartridges,” filed Jan. 16, 2023 and assigned to the assignee hereof and hereby expressly incorporated by reference herein.

FIELD OF THE DISCLOSURE

The present disclosure relates generally to firearm magazines. In particular, but not by way of limitation, the present disclosure relates to a non-linear firearm magazine for use with high ballistic coefficient cartridges.

DESCRIPTION OF RELATED ART

Box magazines with longer-range, higher ballistic-coefficient cartridges supporting warfighting concepts such as overmatch present new challenges to reliability. Typically, higher ballistic-coefficient cartridges utilize longer bullets which often feature a corresponding decrease in cartridge case length. This combination has unsurprisingly resulted in nose-heavy cartridges with reduced stability in cartridge stacks within magazines. Unfortunately, these cartridges often result in nose-diving failure-to-feed malfunctions which have become increasingly prevalent given the insufficient upward pressure on the front of existing followers within the magazine. Additionally, followers often present flat-on-curved interfaces that do not fully track the inside of the magazine body, inadequate aspect ratios (height) to stabilize the follower and the cartridges within the magazine, and insufficient grit clearances which often induce hang-ups, especially in dusty environments.

Furthermore, existing detachable box magazines used in firearms with linear magazine wells, such as the AR-15 and M16, have thin wall sections in the upper magazine body, where a constant-curve internal geometry is fit within a substantially linear external profile in the upper portion of the magazine body. This design presents a number of issues, such as: flow interruptions in injection-molded polymer magazines, which reduces the overall strength of the magazine, especially in the feed lips; and using the feed lips as a follower stop, which often places the follower in a sub-optimal position when loading from an empty state and can cause undue stress or creep over time. Additionally, for certain magazines as the PMAG LR/SR Gen 3, rear clearance ribs typically stop short of the upper portion of the magazine, where the magazine slots into the magazine well, to properly fit inside existing magazine well profiles, and vertical linear magazine wells typically force less optimal internal curvatures to be used to fit within the given profile and deviate from an ideal spherical round stack. Thus, there is currently a need for a firearm magazine with improved internal curvature and increased anti-tilt follower functionality especially for high ballistic-coefficient cartridges.

SUMMARY OF THE DISCLOSURE

The following presents a simplified summary relating to one or more aspects and/or embodiments disclosed herein. As such, the following summary should not be considered an extensive overview relating to all contemplated aspects and/or embodiments, nor should the following summary be regarded to identify key or critical elements relating to all contemplated aspects and/or embodiments or to delineate the scope associated with any particular aspect and/or embodiment. Accordingly, the following summary has the sole purpose to present certain concepts relating to one or more aspects and/or embodiments relating to the mechanisms disclosed herein in a simplified form to precede the detailed description presented below.

Some embodiments of the disclosure may be characterized as a firearm magazine comprising: a magazine body having feed lips at a top end; an anti-tilt follower assembly housed within the magazine body; a lock plate; a floor plate; a spring; one or more ribs within the magazine body, wherein the one or more ribs extend from a bottom to at or near a top of the magazine body; and one or more channels within the magazine body; wherein the one or more ribs and the one or more channels have a consistent profile along their length. In some embodiments, the outer front and rear ends of the magazine body are angled forward relative to a plane across a top of the feed lips. In some embodiments, the magazine further comprises a plurality of external contours on the magazine body, wherein an upper portion of the magazine body configured for reception within a magazine well has an uninterrupted profile as it extends down and to the plurality of external contours. In many embodiments, the magazine further comprises a first follower stop at the rear of the magazine body relieving the feed lips from being used as a primary rear follower stop and a second follower stop at the front of the magazine body. In various embodiments, one or more rear ribs extend into one or more follower stops, wherein the one or more follower stops expand laterally from a top of the one or more rear ribs and are configured to interface with a top rear of the follower assembly when the firearm magazine is empty. In many embodiments, the anti-tilt follower assembly further comprises a front tine and a rear tine, with one or both tines having a curvature to substantially correspond with curvature of an inside of the magazine body, and the front tine is configured to extend below a topmost planar surface of a lock plate of the magazine, and wherein a front portion of a top of the lock plate is recessed to accept a bottom of the front tine. In many embodiments, the follower assembly further comprises a false round supported by false round support ribs, the false round support ribs being formed beneath the false round of the follower assembly and configured to support the false round under compressive forces from a firearm bolt, and a support extending from the rear of the front tine to a front of the rear tine is configured to provide structural support to a center of the follower assembly and reinforce the false round support ribs. In many embodiments, the lock plate has a reduction in material thickness such that the front tine of the follower assembly is configured to contact, or nestle into the reduction of, the lock plate when the firearm magazine is fully loaded.

In some embodiments, an anti-tilt follower of a firearm magazine comprises a front end having an inner surface with a first curvature; a rear end having an inner surface with a second curvature, a front tine having a front curved end with a similar radius of curvature to that of the first curvature, a rear tine, one or more false round support ribs, a false round, at least two protrusions, and a bolt catch interface. In many embodiments, the protrusions are configured to ride along a front edge of one or more rails. In some embodiments, the rear tine has a rear curved end with a similar radius of curvature to that of the second curvature, and the curvature of the front tine and rear tine assists in biasing one or more nose of cartridges within the magazine body upwards. In various embodiments, the bolt catch interface is configured to interact with a bolt in the firearm magazine to facilitate locking the bolt after a final round is fired. In some embodiments, the false round support ribs are formed beneath the false round of the anti-tilt follower and mechanically support the false round. In other embodiments, the follower further comprises a support coupled to the center of the anti-tilt follower and the support is formed beneath the false round and extends between a rear of the front tine to a front of the rear tine. In many embodiments, the anti-tilt follower further comprises a rear pad, a front tine, and a front tine pad coupled to a rear portion of the front tine, wherein the front tine pad is configured to push against a rail to counteract a nose-down orientation.

Embodiments of a method of molding a polymer follower for a firearm magazine are also provided. The method comprises providing a mold having a mold core and a mold cavity; moving the mold core toward the mold cavity along an axis to close the mold; injecting a liquid polymer into the mold between the mold core and the mold cavity; allowing the polymer to at least partially solidify to form a follower; moving the mold core away from the mold cavity along the axis to open the mold; and releasing the follower from the mold. In some embodiments, the step of allowing the polymer to at least partially solidify to form a follower comprises forming the follower having a front tine with a convex front end and supporting ribs within a dummy cartridge, the supporting ribs being substantially parallel to the axis. In some embodiments, the step of injecting a liquid polymer into the mold between the mold core and the mold cavity uses a side-to-side injection molding process.

BRIEF DESCRIPTION OF THE DRAWINGS

Various objects and advantages and a more complete understanding of the present disclosure are apparent and more readily appreciated by referring to the following detailed description and to the appended claims when taken in conjunction with the accompanying drawings:

FIG. 1 is a left, rear, top perspective view of a magazine in accordance with an embodiment of the present invention;

FIG. 2 is a left side view of a magazine in accordance with an embodiment of the present invention;

FIG. 3 is a right side view of a magazine in accordance with an embodiment of the present invention;

FIG. 4 is a front view of a magazine in accordance with an embodiment of the present invention;

FIG. 5 is a back view of a magazine in accordance with an embodiment of the present invention;

FIG. 6 is a top view of a magazine with a follower in accordance with an embodiment of the present invention;

FIG. 7 is a bottom view of a magazine in accordance with an embodiment of the present invention;

FIG. 8 is a bottom perspective view of a magazine without a follower, floorplate, or lock plate visible in accordance with an embodiment of the present invention;

FIG. 9 is a bottom, left, rear perspective view of a magazine without a follower, floorplate or lock plate visible in accordance with an embodiment of the present invention;

FIG. 10 is a top, left, front perspective view of a magazine without a follower visible in accordance with an embodiment of the present invention;

FIG. 11 is a left side perspective view of a follower in accordance with an embodiment of the present invention;

FIG. 12 is a top, right, front perspective view of a follower in accordance with an embodiment of the present invention;

FIG. 13 is a top perspective view of a lock plate in accordance with an embodiment of the present invention;

FIG. 14 is bottom, right, front perspective view of a floor plate and a lock plate in accordance with an embodiment of the present invention;

FIG. 15 is an exploded perspective view of a magazine in accordance with an embodiment of the present invention;

FIG. 16 is a top, left, rear perspective view of a follower in accordance with an embodiment of the present invention;

FIG. 17 is a side perspective view of a floor plate and a lock plate in accordance with an embodiment of the present invention; and

FIG. 18 is a flow chart of a method of molding a polymer follower for a firearm magazine in accordance with an embodiment of the present invention.

DETAILED DESCRIPTION

The present disclosure relates generally to firearm magazines. In particular, but not by way of limitation, the present disclosure relates to a non-linear firearm magazine for use with high ballistic coefficient cartridge.

The word “exemplary” is used herein to mean “serving as an example, instance, or illustration.” Any embodiment described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments.

Preliminary note: the flowcharts and block diagrams in the following Figures illustrate the functionality and operation of possible implementations of a firearm magazine according to various embodiments of the present disclosure. It should be noted that, in some alternative implementations, the functions noted in each block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved.

It will be understood that, although the terms first, second, third etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another region, layer or section. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the present disclosure.

Spatially relative terms, such as “beneath,” “below,” “lower,” “under,” “above,” “upper,” and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “below” or “beneath” or “under” other elements or features would then be oriented “above” the other elements or features. Thus, the exemplary terms “below” and “under” can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly. In addition, it will also be understood that when a layer is referred to as being “between” two layers, it can be the only layer between the two layers, or one or more intervening layers may also be present.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items and may be abbreviated as “/”.

It will be understood that when an element or layer is referred to as being “on,” “connected to,” “coupled to,” or “adjacent to” another element or layer, it can be directly on, connected, coupled, or adjacent to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being “directly on,” “directly connected to,” “directly coupled to,” or “immediately adjacent to” another element or layer, there are no intervening elements or layers present.

Embodiments of the disclosure are described herein with reference to cross-section illustrations that are schematic illustrations of idealized embodiments (and intermediate structures) of the disclosure. As such, variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and/or tolerances, are to be expected. Thus, embodiments of the disclosure should not be construed as limited to the particular shapes of regions illustrated herein but are to include deviations in shapes that result, for example, from manufacturing. Accordingly, the regions illustrated in the figures are schematic in nature and their shapes are not intended to illustrate the actual shape of a region of a device and are not intended to limit the scope of the disclosure.

As used herein, the recitation of “at least one of A, B and C” is intended to mean “either A, B, C or any combination of A, B and C.” The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present disclosure. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the disclosure. Thus, the present disclosure is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and/or the present specification and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

Many firearm magazines utilize some type of follower assembly, typically along with a spring-based pushing mechanism, to feed ammunition (cartridges) from the magazine into a firearm. The follower assembly is generally situated beneath an ammunition cartridge stack and is configured to push the cartridges along a path that exits the magazine through an open end of the magazine, often called the “feed end,” which interfaces with the firearm. Existing follower assemblies are suitable for traditional cartridges having a center of gravity in the center or rear of the cartridge. However, many newer cartridges developed for longer-range use have a more forward-centric center of gravity, known to be “nose-heavy,” leading to more frequent misfeeds. Nose-heavy high ballistic coefficient cartridges have typically been used in bolt-action or low-capacity magazine platforms, where feeding issues are less of a concern. However, as the military has adapted these types of rounds for semi-auto and full-auto applications, where the complications of magazine feeding exist, the tendency of these rounds to nosedive presents reliability issues. The present disclosure provides various improvements to address the nose-heavy nature of high-ballistic coefficient cartridges.

FIGS. 1-5 illustrate a firearm magazine 100 comprising a magazine body 102 housing an anti-tilt follower assembly 104, a lock plate 107 (see FIG. 13), a floor plate 106, feed lips 114 and a spring (not shown). The follower 104, lock plate 107, and floor plate 106 design is configured to ensure that the follower 104 and cartridges (not shown) do not bind, or otherwise jam within the magazine body 102. An upper portion of the magazine body 102 is configured to be arranged within a magazine well.

In general, the ideal round stack for tapered cartridges is spherical. In a stick-type magazine, it is therefore desirable to have a fully curved magazine. However, previous firearm magazines had to adapt around the already existing AR magazine well, which was largely linear to aid in magazine insertion and removal, while incorporating a substantially continuous curve to greatly improve round stack consistency. The drawback however is that the stack deviates from the ideal spherical shape and consequently positions the cartridges in a more nose-down configuration. In contrast, vertically-oriented straight magazine wells deviate from the spherical shape of the magazine, and consequently position the cartridges in a more nose-down configurations.

This disclosure overcomes these challenges via use of a magazine well with a straight yet angled inner well and a magazine that is similarly angled (see FIG. 3). In various embodiments, an upper portion of the magazine body 102 may be angled at an angle a (see FIG. 2) relative to a plane across a top of the feed lips. That is, the outer front and rear ends of the magazine body 102 may couple to the magazine well at an angle α relative to a top of the feed lips (or the bore axis), and the inner magazine well may also be at an angle α relative to a top of the feed lips or the bore axis (e.g., see FIG. 3 showing a unique angled inner magazine well). The angle may also be referenced relative to a longitudinal axis of a last remaining round or the exterior of the magazine well on the firearm. In some embodiments, the outer front and rear ends of the magazine body are angled forward relative to a plane across a top of the feed lips (see line 150 passing along this invisible plane). Said another way, the outer front and rear ends of the magazine body are angled forward or upward relative to a bore axis of a firearm. As such, the round stack is positioned in a more upward-facing position, better mimicking the ideal spherical round stack. This allows the exterior of the magazine contained within the well section to be more closely aligned with the interior position of a truly spherical stack. This combination allows for 1) better feeding through a continuous curve stack oriented in a more ideal position with 2) more rapid drop-free magazine ejection of a linear magazine well.

In many embodiments, the magazine body 102 comprises a plurality of internal ribs (e.g., see items 812 in FIG. 8) and a plurality of external contours 110 that seamlessly blend into a cross section of an upper portion of the magazine 100. In other words, a profile or cross section of the magazine when viewed from above or below does not see an interruption in this profile or cross section as one moves from the lower to the upper portion of the magazine 100. This uninterrupted transition from the upper to lower portion of the body can also be seen in FIGS. 4 and 5, where a width of the upper portion is substantially the same as the width of the lower portion. While the external contours 110 are illustrated as a waffle pattern, in other embodiments, the external contours could take the form of alternative shapes and patterns such as a grid of hexagons or circles.

In comparison, traditional magazines have profile interruptions that are at least partially dictated by specifications/requirements of a traditional AR-15-style magazine well. In particular, a lower portion of a magazine, or the portion below a magazine well when inserted into a rifle, may have a raised pattern such as a waffle or hexagon pattern. However, within the area where the magazine interfaces with the magazine well, the outside of the magazine may be substantially bereft of any raised portions. Thus, the profile of the lower portion is interrupted upon transitioning to the upper portion (i.e., the lower portion includes a raised pattern or features, whereas the upper portion largely does not include any raised portions aside from, for instance, a magazine catch). The profile interruptions in traditional magazines allow for more resin degradation and fiber-reinforcement breakage during manufacturing. Various embodiments in the present disclosure utilize a magazine designed for a custom magazine well such that the magazine avoids these traditional profile interruptions.

This wider upper portion of the magazine 100 also allows more internal volume in the upper portion, an area normally constrained by preexisting magazine wells designed for metallic magazines. Here, because a unique and wider magazine well is being implemented, the outer profile of the upper portion is wider than in the art and as a result an inner volume of the upper portion of the magazine 100 can include internal ribs that extend up and through most if not all of the upper portion, a region that typically does not allow sufficient volume to continue these ribs toward a top of the magazine. Because rear internal ribs (e.g., see 814 in FIG. 8) are allowed to remain uninterrupted from the bottom to the top, or near the top, of the magazine body 102, there is less resistance on follower travel in the upper portion of the magazine 100 and more room for a channel between rear ribs to allow dirt and debris to reside (helping to avoid jams).

In addition to the typical front follower stop 1012a, a rear follower stop 1012b is arranged at a rear of the magazine body 102 (see FIG. 10). Existing magazines often rely on a dummy cartridge extending above the follower platform to nestle into the curvature of one of the feed lips, this interface acting as a follower stop. However, such designs can apply stress to a polymer feed lip and place uneven stress on the two feed lips. The present design overcomes this with the addition of the rear follower stop 812b/1012b, which interfaces with a top of a bolt catch interface 1119 (see FIG. 12). This bolt catch interface 1119 of the follower acts much like the front detent 612 of the magazine (see FIG. 6) to stop the follower 1104 from extending excessively far into the magazine well. By using a front and rear follower stop 1012a and 1012b the dummy cartridge is prevented from touching the feed lips 1014, thereby relieving stress placed on the feed lips by prior designs, and enabling a novel follower platform angle when confronting the bolt (while follower angle is typically dictated by the requirements of the feed lips, here, the rear follower stop can be tailored in height to achieve a desired follower platform angle).

FIG. 6 illustrates a top view of the firearm magazine 600 of FIGS. 1-5, and provides an additional view of the two follower stops and the interface with the follower. As seen, the magazine 600 may comprise a magazine body 602, an anti-tilt follower 604, a front detent 612, at least two feed lips 614, and a false round or dummy cartridge 616. The follower may comprise a left or front end 601 and a right or rear end 603. In many embodiments, the front detent 612 is configured to stop the follower 604 from extending excessively far into the magazine well. The front detent 612 of the magazine is configured to couple/interact with the front recession 622 of the follower 604. For example, with further reference to FIG. 12, the front detent 612 of the magazine 600 interacts with the front recession 1122 of the follower 1104, such that it stops movement of the follower 1104 when the detent 612 makes contact with the bottom floor 1130 of the recession 1122.

FIG. 7 illustrates a bottom view of the firearm magazine 700 of FIGS. 1-6, wherein the magazine 700 further comprises a lock plate 707 and a floor plate 706. The lock plate 707 may be configured to support a spring (not shown) and prevent the cartridges in the magazine body 702 from being ejected from the bottom of the magazine 700. The floor plate 706 is configured to secure the lock plate in place and may also assist in preventing cartridges from being ejected from the bottom of the magazine 700.

In some instances, with reference to an embodiment in FIG. 15, the lock plate 1308 may be configured to couple to the floor plate 1306 and the floor plate 1306 may be configured to slidingly engage with a bottom receiving portion 1305 of the magazine body 102.

FIGS. 8-9 illustrate bottom views of the firearm magazine 800 absent internal components such as the follower, follower spring, floor plate and lock plate. As shown, the magazine 800 may comprise a plurality of ribs 805 and 814, and channels 811a/b, The channels 811a/b (or troughs) allow room for dirt, debris, and other grime that might interfere with smooth traversing of the follower. Further, the ribs 814 decrease friction on the back of the follower, by reducing the surface area that contacts the back of the follower, to facilitate its traversing through the magazine 800. The present embodiment mitigates dirt or other contaminants from interfering with the transit of the follower (i.e., mitigate sticking or shimmying of the follower as it traverses up and down, which could occur were the back spine flat). Further, given the wider internal volume in the upper portion of the magazine, the ribs 814 and by extension the troughs 811a/b, are able to stretch into the upper portion of the magazine 800 and to or nearly to a top of the magazine 800. What is more, because the ribs 814 are able to extend nearly to a top of the magazine 800, a rear follower stop 812b can be arranged at a top of the ribs 814 to interface with a stop of a bolt catch interface 1119, something not possible with existing magazines where the ribs recede into the rear inner wall in the upper portion of the magazine (and hence the need to use the feed lips as the rear follower stop).

Further, a composite glass's (and resin's) propensity to break while being injected with plastic is reduced—the glass fibers provide strength and stiffness to the composite, making it less prone to breaking. Further, since the ribs and channels are longer than in previous designs, their strength and stiffness is improved, that is, the longer internal ribs distribute applied loads (forces) over a larger area, which helps prevent localized stress concentrations and reduces the risk of failure or deformation under load. In addition, the longer ribs and channels offer better resistance to magazine wall bending or flexing.

Unlike traditional designs, the ribs 814 are extended from a bottom to a top, or nearly a top, of the magazine, thereby extending a distance over which friction on the rear of the follower is minimized, and also maximizing the space in which dirt, grime, and other contaminants can find their way without interfering with follower traversal. Along these same lines the rear ribs 814 extend into follower stops 812b, which expand laterally and inward from a top of the rear ribs 814. A front rib 812a also extends from a bottom to nearly a top of the magazine (i.e., substantially a full height of the magazine body).

FIG. 10 illustrates a top view of the firearm magazine 1000 absent internal components such as the follower, follower spring, floor plate and lock plate. As shown, the magazine 1000 may comprise a plurality of ribs 1005 and channels 1011a/b within the magazine body 1002. The magazine body 1002 may further comprise two or more feed lips 1014, a front follower stop 1012a, and at least one rear follower stop 1012b as previously described.

FIGS. 11-12 illustrate views of the anti-tilt follower 1104 in isolation. The follower 1104 may comprise a front end 1101 and a rear end 1103, a front tine 1111, a rear tine 1113, a dummy cartridge or false round 1117, false round support ribs 1115, at least two protrusions 1118 extending off the front tine, and a bolt catch interface 1119 or rear detent. The protrusions 1118 (up to four may be found on the front tine 1111—two on each side) can ride along a front edge of rails 1013 (see FIG. 10) to help improve anti-tilt. The front end of tine 1111 is arranged along a curve that is similar to or substantially mimics a curvature of the front edge of rails 1013 and/or the front rib 812a better seen in FIGS. 8, 9 and 14. Further, the use of two protrusions 1118 on each side of the tine 1111, compared to a single long protrusion, reduces friction between the front tine 1111 and the rails 1013. In some embodiments, protrusions 1118 are rounded and ride on the front edge of the rails, but provide reduced friction compared to a single long protrusion.

In some instances, the follower 1104 is formed via side-to-side (in and out of the page in FIG. 11) injection molding systems and methods as compared to the typical top-to-bottom mold split. The side-to-side tooling split method allows for the formation of a follower 1104 having a delicate tooling geometry and one that better contours to the curvature of the magazine body. For example, with reference to an embodiment in FIG. 18, a method 1800 of molding a polymer follower for a firearm magazine comprises providing a mold having a mold core and a mold cavity 1802, moving the mold core toward the mold cavity along an axis to close the mold 1804. Next a liquid polymer is injected into the mold between the mold core and the mold cavity 1806, allowing the polymer to at least partially solidify to form a follower 1808. In some embodiments the follower is formed having a front tine with a convex front end and supporting ribs within a dummy cartridge, the supporting ribs being substantially parallel to the axis. The method 1800 includes moving the mold core away from the mold cavity along the axis to open the mold 1810 and releasing the follower from the mold 1812.

In many embodiments, a side-to-side mold split for injection molding is used and allows for the formation of features of the follower 1104 that were not previously possible with current top-bottom injection mold split methods. For example, some features can be formed with shallower pockets or cavities, thereby allowing for stronger polymer sidewalls to these pockets as well as allowing improved, reinforced, free-standing mold sections, both in turn enabling more robust, larger-volume production. For example, the side-to-side tooling configuration allows the follower 1104 to be formed without having to use mold structures having the same elongation as traditional followers. For instance, traditional molds include an elongated ‘tower’ to form a void within the front tine. In a side-to-side configuration, a pocket can be created on either side of the front tine instead of a single elongated void within, and these allow for much shorter and more robust mold structures to be used to form these pockets. Side-to-side tooling splits allows for curved tines which improve tracking of the curved internal components of the magazine body 1102 (e.g., see 812a, 805, and 814 in FIG. 8). The front follower tine 1111 has a concave curvature on a front end and the rear follower tine 1113 has a convex curvature on a rear end, both to better align with the curvature of the inside of the magazine and of a round stack within the magazine body 1102. By mimicking or approaching this same curvature, the curvature of the tines assists in biasing the nose of cartridges within the magazine body 1102 upwards, especially helpful with cartridges that have a longer projectile-to-casing length ratio. When the final cartridge is expended, the bolt catch interface 1119 can interact with the bolt to help lock back the bolt after a final round is fired (see the bolt catch interface 1119 extending above a rear of the magazine body 110).

In some embodiments, the false round support ribs 1115 are formed beneath the false round 1117 of the follower 1104 and may mechanically support the false round 1117 under various stresses, such as an impact from the bolt if released on an empty magazine or if the last-round hold open function malfunctions. There may be one or numerous false round support ribs 1115 on the follower 1104.

A support 1126 may be configured to provide structural support to the center of the follower 1104 and reinforce the false round support ribs 1115 as well. Further, the support 1126 may be formed beneath the false round 1117 and extend from the rear of the front tine 1111 to the front of the rear tine 1113 (although as illustrated it does not extend fully between the tines 1111, 1113). In addition, the support 1126 may further accept a top end of a follower spring via an aperture 1125 therein.

In yet another embodiment, a follower platform 1128 (see FIGS. 11 and 12) may be configured to interface with a last cartridge of the magazine 100. The platform 1128 may be configured to interface with a cartridge at an angle relative to a longitudinal axis of the magazine 100 (or a feed path of the follower). This angle may include a front to back slope (with the back being higher than the front as shown in FIG. 11) as well as a side-to-side slope (not shown).

In another embodiment, two rear recessions 1121 on either side of the bolt catch interface 1119 are configured to interface with follower stop 1012b (FIG. 10) and cause the follower front end to kick up when a final cartridge leaves the magazine 100. The kicking up of the front end of the follower along with continued upward pressure from the follower 104 spring, may assist in directing force from the bolt catch interface 1119 into a bolt lock-back mechanism (not shown) of a firearm. Additionally, the follower 1104 may comprise a front recession 1122 on the front tine 1111, the front recession 1122 configured to interface with the front follower stop (e.g., see 1012a in FIG. 10).

FIGS. 13-14, and 17 illustrate a lock plate 1308 and a floor plate 1306 in isolation. In some embodiments the lock plate 1308 and floor plate 1306 have a reduction 1702 (see FIG. 17) in material thickness toward a front of the lock plate 1308, where the front tine (e.g., 1111, see FIGS. 11-12 and 15) of the follower (e.g., see FIGS. 1-6) is configured to contact when the magazine (e.g., 100 in FIG. 1) is fully loaded. This reduction 1702 allows for a slight extension in the length of the front follower tine 1111, thereby providing additional anti-tilt effect and further preventing the follower (e.g., see 1104 in FIG. 11) from binding or jamming within the magazine body (e.g., see 1002 in FIG. 10). While similar functionality could be added by lengthening the magazine (e.g., 100 in FIG. 1), the use of the reduction 1702 instead, optimizes functionality within a given magazine length and makes for a more compact package (e.g., 100 in FIG. 1), improved handling, and may meet magazine-length criteria for certain competitions.

FIG. 15 shows an exploded view of the firearm magazine 1500 of FIGS. 1-14.

FIG. 16 illustrates an embodiment of a follower with extending pads on the rear of both tines. In some instances, the follower 1600 includes a front tine pad 1604 added to a rear portion of the front tine so that follower 1600 travel better matches the curvature of the cartridge stack and curvature of the inside of the magazine body. In particular, this pad 1604 pushes against a side rail (e.g., 1013) to help push the front of the follower 1600 upward. This can be helpful in reducing nose-dive caused by a shorter spring that is arranged more rearward than on traditional magazines (as a byproduct of the shorter cartridge case length). A rear pad 1602 extending from a rear of the rear tine and more specifically from the bolt catch interface, can help create more clearance between a rear of the follower 1600 and the rear spine of the inside of the magazine, to help allow for added grit clearance. In addition, the front tine pad 1604 is configured to contact rib 1013 in the magazine body when any torque is applied to the follower. The pad configuration additionally allows for clearance for the follower and allows for variability, if needed, during the injection molding process.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the presently disclosed embodiments. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the presently disclosed embodiments. Thus, the presently disclosed embodiments are not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A firearm magazine comprising:

a magazine body, the magazine body having feed lips at a top end;

an anti-tilt follower assembly housed within the magazine body;

a lock plate;

a floor plate;

a spring;

one or more ribs within the magazine body, wherein the one or more ribs extend from a bottom to at or near a top of the magazine body; and

one or more channels within the magazine body; wherein the one or more ribs and the one or more channels have a consistent profile along their length.

2. The firearm magazine of claim 1, wherein an upper portion of the magazine body is angled at an angle a relative to a plane across a top of the feed lips.

3. The firearm magazine of claim 1, further comprising a plurality of external contours on the magazine body, wherein an upper portion of the magazine body configured for reception within a magazine well has an uninterrupted profile as it extends down and to the plurality of external contours.

4. The firearm magazine of claim 1, further comprising a first follower stop at a rear of the magazine body relieving one or more feed lips from being used as a primary rear follower stop.

5. The firearm magazine of claim 4, further comprising a second follower stop at a front of the magazine body.

6. The firearm magazine of claim 1, wherein one or more rear ribs extend into one or more follower stops, wherein the one or more follower stops expand laterally from a top of the one or more rear ribs and are configured to interface with a top rear of the anti-tilt follower assembly when the firearm magazine is empty.

7. The firearm magazine of claim 1, wherein the anti-tilt follower assembly further comprises a front tine and a rear tine, each tine having a curvature to substantially correspond with curvature of an inside of the magazine body.

8. The firearm magazine of claim 7, wherein the front tine is configured to extend below a topmost planar surface of a lock plate of the firearm magazine, and wherein a front portion of a top of the lock plate is recessed to accept a bottom of the front tine.

9. The firearm magazine of claim 1, wherein the anti-tilt follower assembly further comprises a false round supported by false round support ribs, the false round support ribs being formed beneath the false round of the anti-tilt follower assembly and configured to support the false round under compressive forces from a firearm bolt.

10. The firearm magazine of claim 9, wherein a support extending from a rear of a front tine to a front of a rear tine is configured to provide structural support to a center of the anti-tilt follower assembly and reinforce the false round support ribs.

11. The firearm magazine of claim 7, wherein the lock plate has a reduction in material thickness such that the front tine is configured to nestle in this reduction when the firearm magazine is fully loaded.

12. An anti-tilt follower of a firearm magazine comprising:

a front end having an inner surface with a first curvature;

a rear end having an inner surface with a second curvature;

a front tine having a front curved end with a similar radius of curvature to that of the first curvature;

a rear tine;

one or more false round support ribs;

a false round;

at least two protrusions; and

a bolt catch interface.

13. The anti-tilt follower of claim 12, wherein the at least two protrusions are configured to ride along a front edge of one or more rails.

14. The anti-tilt follower of claim 12, wherein the rear tine has a rear curved end with a similar radius of curvature to that of the second curvature.

15. The anti-tilt follower of claim 14, wherein the curvature of the front tine and the rear tine assists in biasing one or more nose of cartridges within a magazine body upwards.

16. The anti-tilt follower of claim 12, wherein the bolt catch interface is configured to interact with a bolt in the firearm magazine to facilitate locking the bolt after a final round is fired.

17. The anti-tilt follower of claim 12, wherein the one or more false round support ribs are formed beneath the false round of the anti-tilt follower and mechanically support the false round.

18. The anti-tilt follower of claim 12, further comprising a support coupled to a center of the anti-tilt follower.

19. The anti-tilt follower of claim 18, wherein the support is formed beneath the false round and extends between a rear of the front tine to a front of the rear tine.

20. The anti-tilt follower of claim 12, further comprising:

a rear pad;

a front tine; and

a front tine pad coupled to a rear portion of the front tine, the front tine pad shaped corresponding to a curvature of a cartridge;

wherein the front tine pad is configured to push against a rail to counteract a nose-down orientation.

21. A method of molding a polymer follower for a firearm magazine comprising:

providing a mold having a mold core and a mold cavity;

moving the mold core toward the mold cavity along an axis to close the mold;

injecting a liquid polymer into the mold between the mold core and the mold cavity;

allowing the liquid polymer to partially solidify to form a follower;

moving the mold core away from the mold cavity along the axis to open the mold; and

releasing the follower from the mold.

22. The method of claim 21, wherein allowing the liquid polymer to at least partially solidify to form a follower comprises forming the follower having a front tine with a convex front end and supporting ribs within a dummy cartridge, the supporting ribs being substantially parallel to the axis.

23. The method of claim 21, wherein injecting a liquid polymer into the mold between the mold core and the mold cavity uses a side-to-side injection mold split.

24. The method of claim 21, wherein the axis is configured to be perpendicular to a plane that vertically bisects the follower.