MODULAR FIREARM ASSEMBLY

Abstract

Some embodiments may include an apparatus, comprising: a sequentially couplable set of two or more bodies, wherein the two or more bodies of the set are assemblable in a predefined order; the sequentially couplable set of two or more bodies including at least: a body to retain, to a frame of a firearm: 1) at least one grip part of one or more grip parts, or 2) a trigger assembly; and another body to retain the body in the firearm. Other embodiments may be disclosed and/or claimed.

Description

PRIORITY

This non-provisional application claims benefit of U.S. Provisional 63/962,576, filed on Jan. 17, 2026, and U.S. Provisional Application No. 63/760,082, filed on Feb. 18, 2025, each of which is incorporated by reference herein.

BACKGROUND

Firearms, such as pistols, are typically an assembly of serialized and non-serialized parts. For example, in a typical pistol architecture, a pistol may include a serialized component (the frame) with a number of non-serialized parts coupled thereto (including, but not limited to, the components of a slide assembly, a trigger, etc.)

Sig Sauer® uses an alternative pistol architecture for some of its pistol models. This alternative architecture includes a Fire Control Unit (FCU), which is the serialized component. The FCU is described by Sig, as follows:

• • The FCU is the component (frame) that houses a majority of the key functional parts of some handguns; including parts such as the trigger, sear, and slide catch lever; and is the serialized part of the firearm. With the SIG SAUER P320 or P365 modular handguns, the FCU can be easily removed from the grip module and swapped out with a variety of grips, barrels, and slides to create a firearm suited specifically to the shooter and intended use of the handgun.

It would be desirable to provide another alternative firearm architecture.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an exploded side view of a modular firearm, according to various embodiments.

FIG. 2 illustrates a top view of the modular firearm of FIG. 1, with a grip part (e.g., a backstrap) of FIG. 1 shown in a non-tensioned state.

FIG. 3 illustrates a section view taken along a section line of FIG. 2.

FIGS. 4A and 4B illustrate, respectively, a bottom and top view of the modular firearm of FIG. 1, with the grip part (e.g., the backstrap) of FIG. 1 shown in a tensioned state.

FIG. 5 illustrates a section view taken along a section line of FIG. 4B.

FIG. 6A illustrates a rear view of the modular firearm of FIG. 1, with the grip part (e.g., the backstrap) of FIG. 1 shown in a tensioned state.

FIG. 6B illustrates a section view taken along a section line of FIG. 6A, shown in a 2:1 scale.

FIG. 7 illustrates an exploded side view of another modular firearm, according to various embodiments.

FIG. 8 illustrates an exploded isometric view of yet another modular firearm, according to various embodiments.

FIG. 9A illustrates an exploded isometric view of yet another modular firearm, according to various embodiments.

FIG. 9B illustrates a detail view of FIG. 9A.

FIG. 10 illustrates an exploded isometric view of yet another modular firearm, according to various embodiments.

FIG. 11 illustrates an exploded isometric view of yet another modular firearm, according to various embodiments.

FIG. 12 illustrates an exploded isometric view of yet another modular firearm, according to various embodiments.

FIG. 13 illustrates an exploded isometric view of yet another modular firearm, suitable for use with an integrated magwell.

FIG. 14 illustrates a top view of the modular firearm of FIG. 13, with a grip part (e.g., a backstrap) of FIG. 13 shown in a non-tensioned state.

FIG. 15 illustrates a section view taken along a section line of FIG. 14.

FIGS. 16A and 16B illustrate, respectively, a bottom and top view of the modular firearm of FIG. 13, with the grip part (e.g., the backstrap) of FIG. 13 shown in a tensioned state.

FIG. 17 illustrates a section view taken along a section line of FIG. 16B.

FIG. 18A illustrates a detail view of FIG. 17.

FIG. 18B illustrates a rear view of the modular firearm of FIG. 13, with the grip part (e.g., the backstrap) of FIG. 13 shown in a tensioned state.

FIGS. 19A and 19B illustrate exploded isometric views of a modular firearm with a non-serialized trigger assembly, according to various embodiments.

FIG. 20 illustrates a top view of the modular firearm of FIGS. 19A and 19B, with a grip part (e.g., a backstrap) of FIGS. 19A and 19B shown in a non-tensioned state.

FIG. 21A illustrates a section view taken along a section line of FIG. 20.

FIG. 21B illustrates a detail view of FIG. 21A.

FIGS. 22A and 22B illustrate the modular firearm 1900 of FIGS. 19A and 19B in a state during a firing cycle, in which FIG. 22A is a top view and FIG. 22B is a section view taken along a section line of FIG. 22A.

FIG. 22C illustrates a detail view of FIG. 22B.

FIG. 23A illustrates a top view of the modular firearm of FIGS. 19A and 19B, in a state before firing.

FIG. 23B illustrates a section view taken along a section line of FIG. 23A.

FIGS. 23C, 23D, and 23E illustrate, respectively, detail views C, E, and F, of FIG. 23B.

FIG. 24 illustrates a rear view of the modular firearm of FIGS. 19A and 19B.

DETAILED DESCRIPTION

FIG. 1 illustrates an exploded side view of a modular firearm 100, according to various embodiments. FIG. 2 illustrates a top view of the modular firearm 100 of FIG. 1, with a grip part 160 (e.g., a backstrap) of FIG. 1 shown in a non-tensioned state. FIG. 3 illustrates a section view taken along a section line of FIG. 2. FIGS. 4A and 4B illustrate, respectively, a bottom and top view of the modular firearm 100 of FIG. 1, with the grip part 160 (e.g., the backstrap) of FIG. 1 shown in a tensioned state. FIG. 5 illustrates a section view taken along a section line of FIG. 4B. FIG. 6A illustrates a rear view of the modular firearm 100 of FIG. 1, with the grip part 160 (e.g., the backstrap) of FIG. 1 shown in a tensioned state. FIG. 6B illustrates a section view taken along a section line of FIG. 6A, shown in a 2:1 scale.

Referring to FIG. 1, the modular firearm 100 includes a sequentially couplable set of bodies, in which the bodies of the set are assemblable in a predefined sequence/order. In this embodiment, a trigger assembly 150 may be the serialized component of the firearm 100, and the firearm 100 may further include a frame 110 and one or more grip parts (e.g., a backstrap 160 and a magazine funnel 170 in this example). In this particular embodiment, the predefined sequence/order may include:

• • With the trigger assembly 150 located in the frame 110, the user interlocks an upper section of a grip part (e.g., backstrap 160) with the trigger assembly 150.
  • While keeping the grip part (e.g., the backstrap 160) interlocked with the trigger assembly 150, the user may retain the grip part with another body. In this example, the other body is another grip part-the magazine funnel 170. In other examples, such as the example shown in FIG. 13, the other body may be grip frame body 1370 (FIG. 13).

In other embodiments, in which a modular firearm includes a greater number of bodies, the predefined sequence/order may include more operations. For example, referring very briefly to FIG. 12, prior to interlocking the grip part 1260 (e.g., the backstrap) to the trigger assembly 1250, the user may attach other bodies including the trigger guard 1230, the side panels 1220, the frontstrap 1240, the recoil cushions 1231, etc.

It may be possible and practical to reverse the sequence/order in other embodiments. For example, it may be possible and practical to provide embodiments in which a backstrap is installed earlier in the predefined sequence/order. For example, it may be possible to provide an embodiment in which a lower part of the backstrap is interlocked with another body before interlocking a trigger assembly with an upper part of the backstrap. Or, it may be practical and possible to provide an embodiment in which a trigger guard is attached at the end of the sequence/order, after attaching other bodies such as a backstrap, side panels, etc.

Referring again to FIG. 1, one aspect of various embodiments described herein is that the grip part 160 (e.g., a backstrap) may be retained using a spring biased sliding part (e.g., the illustrated plunger at the bottom of the grip part 160). The spring biased sliding part may be biased along its direction of movement to cause engagement, and releasable or disengagable by a force from a direction opposite the biasing force. The spring biased sliding part may also be released with a single tool (rather than two tools, which require two hands and/or a vice as with the punch/hammer tool requirement), and/or an improvised tool (such as a paper clip). In other embodiments, it may be possible and practical to provide a spring biased sliding part that is toollessly actuatable.

Another aspect of various embodiments described herein can best be understood in comparison to how known trigger assemblies are release from known firearms. In known firearms, the fastener that is removed to release the trigger assembly (using a hammer and punch, and possibly a vice for some users) is one that contacts the trigger assembly (it is coincident with the trigger assembly, e.g., passes through the trigger assembly). In contrast, with reference to FIG. 1, the spring-biased part (e.g., the illustrated plunger on the bottom of the backstrap 160) does not contact the body of the trigger assembly 150. As another example, referring briefly to FIG. 9A, in which the trigger assembly 950 is retained at its front end using interlocking between the projection 921 and the frontmost part 951, no fasteners are in contact with the trigger assembly 950. And in FIG. 9A, similar to FIG. 1, to release the trigger assembly 950, the user actuates a spring-biased part that is not contacting the serialized trigger assembly 950 (again, which is different than removing the known pin contacting the known trigger assembly, which again is releasable with a hammer and a punch).

Referring now to FIGS. 1-6B, one of the novel interfaces of the modular firearm 100 is an interface between a serialized component of the firearm and at least one of the additional parts. This novel interface may be referred to as a Serialized-component/non-Serialized part interface (Sc/nSp interface). Referring to FIG. 5, one example of an Sc/nSp interface is interface 105. The interface 105 may, being an Sc/nSp interface, may include 1) a portion of a serialized part (e.g., a portion of a trigger assembly, a serialized frame, or the like), and 2) a portion of a grip part or other non-serialized part. The interface 105, together with various other interfaces, may allow a user to quickly release the various additional parts toollessly (e.g., using only an improvised tool, such as a paper clip), or using a tool (e.g. a single tool and/or a simple tool that may require only one hand to operate—as opposed to two hands as with a punch and a hammer in known trigger assemblies).

Referring now to FIGS. 1, 3, and 5 in combination, the interface 105 (FIG. 5) may include any of the following features:

• • A space 153 (FIG. 1);
  • Another space 163 (FIG. 3);
  • A portion 162 (FIG. 3) of a non-serialized part, which may occupy a portion of the space 153 when the modular firearm 100 is fully assembled; and/or
  • A portion 152 (FIG. 1) of a serialized part, which may occupy a portion of the space 163 when the modular firearm 100 is fully assembled.

When the interface 105 includes more than one space, one of the spaces may be provided by the serialized component, and another one of the spaces may be provided by a backstrap or other non-serialized part. That is what is shown in this embodiment—in which spaces 153 and 163 are provided by a trigger assembly 150 and a backstrap 160, respectively.

It may be possible and practical for the interface 105 to include only a single space, instead of more than one space as with the illustrated embodiment. In such an example, the single space may be provided by the serialized part (e.g., a trigger assembly or a serialized frame), or may be provided by the non-serialized part (e.g., by a backstrap or other grip part).

When the interface 105 includes more than one space, a serialized part portion may be locatable in one of the spaces, and a non-serialized part portion may be locatable in the other one of the spaces. In this example, the serialized part portion is part of a projection 152 (e.g., a lug) of a body 151 of the trigger assembly 150, and the non-serialized part potion is part of a projection 162 of a body of the grip part 160 (e.g., the backstrap).

Referring now to FIGS. 3 and 5 in combination it can be seen that the grip part 160 may be rotated (e.g., pivoted) from the position shown in FIG. 3, to the position shown in FIG. 5. It can also be seen that the lug 152 travels more deeply into the space 163, during this rotation. Put another way, the projection 152 occupies a first portion (or volume) of the space 163 prior to said rotation, and occupies a second portion (which may be a larger volume) of the space 163 when the modular firearm 100 is in a fully assembled state.

Projection 162 similarly may travel more deeply into the space 153 during this rotation. In this example, an upward tab 167 (FIG. 3) of the projection 162 may be essentially positioned in the space 153 in both states (as illustrated), but an angled surface 168 (FIG. 3) of the projection 162, corresponding to the angled surface 158 (FIG. 3) of the lug 152, travels more deeply into the space 153, during this rotation.

Referring now to FIG. 5, to remove the grip part 160 (e.g., the backstrap) after the firearm is fully assembled, in this embodiment the following steps may be performed in the order they are listed below (this may be the opposite order as the sequence/order of installation, in various embodiments):

• • Release the magazine funnel 170 (this may include completely or partially uninstalling the magazine funnel 170, as needed).
  • With the magazine funnel 170 released, permit the grip part 160 to rotate into the position shown in FIG. 3. In some examples, in which the grip part 160 is tensioned, the grip part 160 may essentially spring from the position shown in FIG. 5 into the position shown in FIG. 3, following the release of the magazine funnel 170. Notably, such a force may be provided without the use of a discrete spring part.
  • With the grip part 160 in the position shown in FIG. 3, separate the grip part 160 from the firearm.

A user may wish to perform the steps above to replace a current grip part with a differently sized grip part. This may allow the user to change a characteristic of the grip of the firearm (e.g., make it larger in the case of replacing with a backstrap having a larger palm swell, or making it smaller in the case of replacing with a compact backstrap).

Referring again to FIGS. 3 and 5 in combination, the interface 105 may also be referred to as a tensioning interface. With tensioning, a non-serialized part (e.g., the grip part 160) may be put into tension during assembly. Here, specifically, the grip part 160 may be put into tension as it travels from the position shown in FIG. 3 to the position shown in FIG. 5.

Depending on characteristics of the grip part 160 (e.g., the material its composed from, or any other characteristic thereof), it may be desirable to increase or decrease a magnitude of a maximum tension applied to the grip part 160. This may be done by changing characteristics of components or features of the interface 105 (FIG. 5). For example, one or more characteristics of the lug 152 (FIG. 3), such as a degree of slope of the angled surface 158 (FIG. 3) of the lug 152 and the angled surface 168 (FIG. 3), may be varied from what is shown, to increase or decrease maximum tension magnitude. Alternatively or additionally, any other approach described in the '576 provisional, which is incorporated by reference herein, may be used to increase or decrease maximum tension magnitude.

Referring to FIG. 5, clearance may be provided between a portion of the underside of the grip part 160 and a corresponding surface of a back end of the non-serialized frame 110, as described in more detail in the '576 provisional. Whether or not clearance is provided, engaging portions of the grip part 160 may include an upper portion to engage the trigger assembly 105 (e.g., the interface 105, including the sloped surface that engages the sloped surface of the lug), and a lower portion to engage a body of the magazine funnel 170. An undercut interface, such as a dovetail (or some other undercut/projection arrangement), may be used for the engagement with the body of the magazine funnel 170.

Referring again to FIG. 1, the trigger assembly 150 may be similar in any respect to any trigger assembly now known or later developed. In this example, the body 151 of the trigger assembly 150 may differ from known trigger assemblies bodies at least due to having the projection 152 and/or the space 153. In other examples, a known trigger assembly may be retrofitted with an additional part, so that it includes a projection and/or space. In some examples, a known trigger assembly feature, such as a hole 159 for a safety lever pin, may be re-purposed as an anchor point to attach an additional part to the known body, to provide the projection or undercut. It may be possible and practical to attach an additional part to a known trigger assembly in any other way, to provide the projection and/or space.

FIG. 7 illustrates an exploded side view of another modular firearm 700, according to various embodiments. The modular firearm 700 may be similar in any respect to the modular firearm 100. In particular, the illustrated Sc/nSp interface may be similar in any respect to interface 105 (FIG. 5).

Referring still to FIG. 7, an assembly including the non-serialized frame 710 and the grip part 720 (e.g., a separable grip) may be similar in any respect to the non-serialized frame 110. It is noted that the non-serialized frame 710, or any other body to receive a serialized trigger assembly 750, may be referred to as a “non-serialized body” or simply frame to receive a serialized trigger assembly, to distinguish from serialized frames. The interface by which the non-serialized frame 710 and the grip part 720 may interconnect maybe be any slidably releasable interface, such as an undercut interface (e.g., a dovetail). In this example, the undercut is provided on grip part 720, and the projection is provided on the non-serialized frame 710. This interface can be seen in more detail in the '576 provisional, which is incorporated by reference. The serialized trigger assembly 750 may be similar in any respect to trigger assembly 150 (FIG. 1).

FIG. 8 illustrates an exploded isometric view of yet another modular firearm 800, according to various embodiments. The modular firearm 800 may be similar in any respect to the modular firearm 100. In particular, the illustrated Sc/nSp interface may be similar in any respect to interface 105 (FIG. 5).

Referring still to FIG. 8, an assembly including the non-serialized frame 810 and the grip part 820 (e.g., a separable grip including an integrated trigger guard) may be similar in any respect to the non-serialized frame 110 (FIG. 1). The non-serialized frame 810 and the grip part 820 may use an undercut interface similar in any respect to any undercut interface described herein. The trigger guard may couple to the non-serialized frame 810 using an additional part, such as a threaded fastener.

It may be possible and practical to use a non-threaded additional part in place of the threaded additional part shown in FIG. 8. For example, a spring-biased part, may be used in place of the threaded additional part shown in FIG. 8. In some other examples, or any other additional part now known or later developed may be used in place of the threaded additional part shown in FIG. 8. In yet other examples, an additional part may not be required (e.g., the body of the trigger guard may attach to the body of the frame body without requiring an additional part).

FIG. 9A illustrates an exploded isometric view of yet another modular firearm 900, according to various embodiments. FIG. 9B illustrates a detail of FIG. 9A. The modular firearm 900 may be similar in any respect to the modular firearm 100. In particular, the illustrated Sc/nSp interface may be similar in any respect to interface 105 (FIG. 5).

By way of background, in a known trigger assembly, a trigger guard part may be used to retain a trigger assembly. In a known FCU, a front portion of the known FCU may attach to the body that contains the FCU (which may be called a body of the non-serialized frame). In such an approach, a front end of the known FCU may contain a pocket. A small metal projection in a bottom of a channel of the body of the non-serialized frame may be received by this pocket of the front end of the FCU. This may hold down the front end of the known FCU (e.g., hold it down relative to the body of the non-serialized frame that contains it). A similar approach is utilized in the modular firearm 100 (FIG. 1).

Comparing FIG. 9A to FIG. 1, several differences are immediately apparent. In FIG. 9A, a projection 921 provided on the top of the frontmost part of the trigger guard (this projection may be called a tab) extends through an access port in the non-serialized frame 910, and a channel of the non-serialized frame 910. A space 922 (which may be referred to as a pocket), between the tab 921 and the top of the trigger guard, may also located in the channel of the body of the non-serialized frame 910.

A frontmost part 951 of the trigger assembly 950, which may be called a “front toe,” simply a projection, may fit into the pocket 922 associated with the tab 921. With the tab 921 extending through the access port, a user may slip the front toe/projection 921 into the pocket 922. In various embodiments this may be done by 1) holding the trigger assembly at an angle similar to how it is shown in FIG. 9A while slipping the front toe 951 into the pocket 922, and 2) then pivoting the trigger assembly 950 downward to fully locate its rear portion in the channel (where that rear portion can be interlocked with a backstrap).

Using the approach described above, in which the body of the trigger guard and the trigger assembly 950 interlock, may eliminate the need for the known interface of the additional small metal projection in a bottom of a channel of a body of a frame. This may reduce build cost, and may also improve build time (e.g., the cost and time to manufacture the body of the frame body may be reduced compared to the cost and time to manufacture the body of the known frame with the small metal part to retain the trigger assembly). Also, the interlocking of the front toe with the pocket corresponding to the tab may be performed more easily by a user in the field, than the known attachment interface that involves the small metal tab (such as in poor lighting). The interlocking of the front toe with the pocket may also more securely retain the trigger assembly

Referring now to FIG. 9B, a back of the grip part 920 may include a small swell 921 (a small bump or other projection) to contact the illustrated backstrap. The larger the dimensions of the swell 921, the more tension may be applied to the illustrated backstrap when the modular firearm 900 is assembled.

FIG. 10 illustrates an exploded isometric view of yet another modular firearm 1000, according to various embodiments. The modular firearm 1000 may be similar in any respect to the modular firearm 100. In particular, the illustrated Sc/nSp interface may be similar in any respect to interface 105 (FIG. 5).

An assembly including the non-serialized frame 1010, the trigger guard 1030, and the grip part 1020 may be similar in any respect to the non-serialized frame 110 (FIG. 1). These components may use an undercut interface similar in any respect to any undercut interface described herein. The trigger guard 1030 may couple to the non-serialized frame 1010 using an additional part, such as a threaded fastener. The trigger guard 1030 and the grip part 1020 may fit together as shown.

A rear of the grip part 1020 may be pocketed. These pockets may retain the illustrated recoil cushions 1021, which may be elastic (rubber) parts. When the grip part 1060 (e.g., the backstrap) is installed, the recoil cushions are sandwiched between the grip parts 1020 and 1060.

A size and dimension of the pocketing in the grip part 1020 may be selected to vary a magnitude of the force associated with a tensioned backstrap. For example, making the pockets gradually deepen along their length can be used to increase or decrease the magnitude of the force associated with a tensioned backstrap. Alternatively, the pockets can have uniform depth and the recoil cushions 1021 could have varying front-to-back thickness along their length, to increase or decrease the magnitude of the force associated with a tensioned backstrap. Either approach may perform a similar function as the swell shown in FIG. 9B.

FIG. 11 illustrates an exploded isometric view of yet another modular firearm 1100, according to various embodiments. FIG. 12 illustrates an exploded isometric view of yet another modular firearm 1200, according to various embodiments.

Referring to FIG. 11, the modular firearm 1100 includes side panels 1120. The back end of the side panels is pocketed. These pockets retain the recoil cushions 1121, which may be similar in any respect to any recoil cushion described herein.

This embodiment includes a front grip part 1140 (e.g., a frontstrap). Similar to a backstrap, a separable frontstrap may come in different sizes, which allows a user to change the size of the grip of the firearm. For example, a user with small hands may prefer to replace a stock frontstrap with a thin and compact frontstrap, whereas a user with large hands may prefer to replace a stock frontstrap with a frontstrap having a large forward swell.

A front of the side grip panels 1120 and a back of the frontstrap 1140 may couple using a tongue and groove interface, as illustrated. In other embodiments, it may be possible and practical to reverse the tongue and groove interfaces, or to use some other attachment interfaces, now known or later developed, to couple side grip panels and a frontstrap.

Instead of a threaded additional part, this embodiment includes the illustrated spring-biased parts (e.g., the illustrated plunger assemblies). In various embodiments, the spring-biased part may be actuated using a paper clip or other improvised tool. Referring to FIG. 12, the modular firearm 1200 utilizes a spring-biased part and a threaded part, as illustrated.

Modular Firearm Suitable for an Integrated Magazine Funnel

Various previously illustrated embodiments described herein include a modular firearm with a separable magazine funnel. However, a separable magazine funnel is not required-in some embodiments, it may be desirable to provide 1) a modular firearm with a magazine funnel integrally form on the grip, or 2) a modular firearm with a magazine opening. FIGS. 13-18B illustrate the latter case (e.g., a modular firearm 1300 with a magazine opening 1370).

FIG. 13 illustrates an exploded isometric view of yet another modular firearm 1300, with a magazine opening 1370. FIG. 14 illustrates a top view of the modular firearm 1300 of FIG. 13, with a grip part 1360 (e.g., a backstrap) of FIG. 13 shown in a non-tensioned state. FIG. 15 illustrates a section view taken along a section line of FIG. 14. FIGS. 16A and 16B illustrate, respectively, a bottom and top view of the modular firearm 1300 of FIG. 13, with the grip part 1360 (e.g., the backstrap) of FIG. 13 shown in a tensioned state. FIG. 17 illustrates a section view taken along a section line of FIG. 16B. FIG. 18A illustrates a detail view of FIG. 17. FIG. 18B illustrates a rear view of the modular firearm 1300 of FIG. 13, with the grip part 1360 (e.g., the backstrap) of FIG. 13 shown in a tensioned state.

Referring to FIG. 13, the trigger assembly 1350 may be similar in any respect to any other trigger assembly described herein. The non-serialized frame 1310 may be similar in any respect to the non-serialized frame 110 (FIG. 1). However, a main grip 1320 of the non-serialized frame 1310 includes an interface to retain a lower section of the grip part 1360 (e.g., a backstrap).

The interface of the main grip 1320 of the non-serialized frame 1310 is illustrated in FIG. 15, and is shown in detail in FIG. 18A. It includes an opening 1376 to receive the illustrated spring-biased part (e.g., the illustrated plunger), to retain a lower portion of the grip part 1360. Accessible through the magazine opening 1370 is an access port 1375, which can be used to release the grip part 1360. For example, an improvised tool, such as a paper clip, may be inserted into the access port 1375 to at least partially collapse the illustrated spring, which allows the grip part 1360 to be removed from the modular firearm 1300.

Referring again to FIG. 15, the illustrated interface of the main grip 1320 is suitable for use in a modular firearm having a magazine funnel integrally formed with a grip. It may also be suitable for use in a modular firearm where a user inserts a magazine into a magazine opening similar in any respect to magazine opening 1370.

The illustrated interface of the main grip 1320 may also be suitable for use in a modular firearm with a separable magazine funnel in which the separable magazine funnel is not used to retain a backstrap. In these cases, an interface for attaching the separable magazine funnel to the modular firearm 1300 may be similar to any magazine funnel attachment interface, now known or later developed. An attachment interface may use screws, or may be releasably without requiring a rotational drive tool (e.g., releasable without tools, or using a paperclip or other improved tool).

Referring to FIG. 13, the grip part 1360 (e.g., a backstrap) may have an upper section that may be similar to any other grip part (e.g., any backstrap described herein). A lower section of the grip part 1360 may include an interface to operate with an interface of the main grip 1320 of the non-serialized frame 1310. Also, in this example, the main grip 1320 is integrated with the non-serialized frame 1310, however, it may be possible and practical to use a non-serialized frame and a separable main grip, in which an upper portion of the separable main grip is attachable to the non-serialized frame.

Serialized Frame

In the various illustrated embodiments, the serialized component of the firearm is not the frame, rather it is a different part, such as the trigger assembly in various embodiments. However, any of the features described herein may be used in a firearm having a serialized frame (e.g., a traditional frame). In these examples, a serialized frame (or an assembly thereof) may include any of the features of any frame described herein and/or trigger assembly features described herein. The firearm with the serialized frame may include any of the additional components described herein, and its additional components may be similar in any respect the various additional components described herein.

In a firearm with a non-serialized frame or a serialized frame, the firearm may include a locking block, composed of hard material (e.g., steel), to engage barrel lugs of the barrel. The frame may include wear-resistant rails, of a different material than a body of the frame (e.g., steel rails), to engage the slide assembly. In some examples, each rail may be monolithic, or an assembly or rail segments, such as a front rail segment and a rear rail segment (to provide any component modularity described herein).

FIGS. 19A and 19B illustrate exploded isometric views of a modular firearm 1900 with a serialized frame 1950, according to various embodiments. FIG. 20 illustrates a top view of the modular firearm 1900 of FIGS. 19A and 19B, with a grip part 1960 (e.g., a backstrap) of FIGS. 19A and 19B shown in a non-tensioned state. FIG. 21A illustrates a section view taken along a section line of FIG. 20. FIG. 21B illustrates a detail view of FIG. 21A. FIGS. 22A and 22B illustrate the modular firearm 1900 of FIGS. 19A and 19B in a state during a firing cycle, in which FIG. 22A is a top view and FIG. 22B is a section view taken along a section line of FIG. 22A. FIG. 22C illustrates a detail view of FIG. 22B. FIG. 23A illustrates a top view of the modular firearm 1900 of FIGS. 19A and 19B, in a state before firing. FIG. 23B illustrates a section view taken along a section line of FIG. 23A. FIGS. 23C, 23D, and 23E illustrate, respectively, detail views C, E, and F of FIG. 23B. FIG. 24 illustrates a rear view of the modular firearm 1900 of FIGS. 19A and 19B.

Referring to FIGS. 19A and 19B, the illustrated serialized frame 1950 may be usable with known non-serialized trigger assemblies, such as the non-serialized trigger assemblies used in Glocks®. In the illustration, for brevity the known non-serialized trigger assembly is not shown. It should be understood that any non-serialized frame features described herein may be used in combination with any non-serialized trigger assembly features, now known or later developed. In embodiments with a serialized frame, the serialized frame may house or capture any non-serialized trigger assembly, now known or later developed.

The firearm 1900 also includes a main grip 1920 (e.g., a grip frame), which may be similar in any respect to main grip 820 (FIG. 8), or any other grip part described herein. The serialized frame 1950 and the main grip 1920 may couple in a similar way that the non-serialized frame 810 (FIG. 8) couples with the main grip 820 (FIG. 8).

The firearm 1900 also includes an additional grip part 1960 (e.g., a backstrap). This grip part 1960 may be similar in any respect to grip part 1360 (FIG. 13), or grip part 160 (FIG. 1), or any other grip part described herein. The serialized frame 1950 and the grip part 1960 may couple in a similar way that the non-serialized frame 810 (FIG. 8) couples with the main grip 820 (FIG. 8).

This embodiment of a modular firearm with a serialized frame includes locking block features. Other embodiments of a modular firearm with a serialized frame may not include any of the locking block features, depending on which kind of barrel and/or slide the serialized frame is configured to operate with. The locking block features will be described in more detail in the section “Locking block assembly,” but for now it is noted that the serialized frame 1950 includes an opening 1993 (e.g., a fastener hole) for attaching a locking block assembly to the serialized frame 1950. Other embodiments of a modular firearm with a serialized frame may not be arranged to operate with a locking block assembly, and as such, may omit the opening 1993. Also, it may be possible and practical to omit the opening 1993 even in other embodiments of a modular firearm with a locking block (the locking block may be retained, in a pocket in which it is located, using only the slide assembly).

The firearm 1900 includes a slide assembly 1950, which may be a known slide assembly used in Glocks®. It should be understood that any modular firearm features, including serialized frame features, may be used with pistols that include slide assemblies and/or pistols that do not include slide assemblies.

Referring to FIG. 21B, it can be seen that the serialized frame 1950 and the grip part 1960 may be coupled in a similar way as the body 151 (FIG. 3) and the grip part 160. Also, referring to FIG. 23B, it can be seen that the interface used with the lower part of the grip part 160 is similar to the interface shown in FIG. 18A. Of course, a lower part of the grip part 160 could alternatively include an interface similar to the interface shown in FIG. 6B in other embodiments of a modular firearm with a serialized frame. Also, referring to FIG. 23E, it can be seen that the interface used with the serialized frame 1950 and the main grip 1920 may be similar in any respect to the interface illustrated in FIG. 8.

Locking Block Assembly

With respect to known firearms generally (and not the modular firearms described herein), a metal slide assembly may be used with a polymer receiver. While this may produce a lightweight, and cost effective build; however, some users may prefer to use the metal slide assembly with a metal receiver. Such a combination may have a different feel when firing, as compared to the combination of the metal slide assembly and the polymer receiver.

When the metal slide assembly requires a locking block to operate, as with the Glock®, attempts to replace the polymer receiver with a metal receiver have lead to malfunctions in the firing cycle. In particular, the locking block may not operate as intended, when used with the metal receiver.

By way of background, a pocket for the known locking block is provided in the polymer receiver. The known locking block is arranged to slip-fit into the pocket in the polymer receiver. Attempts to provide the same sized pocket in a metal receiver (to reproduce the exact same structure as with the polymer receiver, in the metal receiver), to try and operate the known locking block with a metal receiver, have lead to the firing cycle problems. The reason why these attempts have failed, is because the more rigid metal receiver does not flex in the same way the polymer receiver flexes in a firing cycle. As a result, in the rigid metal receiver the locking block does not operate the same way it operates in the flexing polymer receiver.

These firing cycle problems can be overcome by utilizing any of the locking block features illustrated in various ones of FIGS. 19A-24. In this arrangement, a locking block assembly is arranged to simulate the operation of the locking block in the flexing polymer receiver, when using a different material (e.g., a metal or some other less flexing material) for the receiver.

The locking block assembly may include a locking block 1990 (which may be similar in any respect to the known locking block), and one or more additional parts. The one or more additional parts may include a locking block cushion 1921 (e.g., a deformable cushion, such as a rubber cushion), to operate with a pocketed metal frame. In some embodiments, the one or more additional parts may also include a pin 1991 shown in FIG. 22C (however it may be possible and practical to omit the pin 1991 in other embodiments, because the locking block may be retained in the pocket by the slide assembly 1955).

The operations of the locking block assembly can best be understood with reference by comparing FIGS. 21A and 22B. In FIG. 21A, when the firearm has not yet been fired (but is ready to fire), the locking block body 1990 and the barrel lugs 1957 are spaced apart a relatively large distance, as shown. Conversely, in FIG. 22B, during the firing cycle when the front end of the barrel is elevated, the barrel lugs 1957 have traveled toward the locking block 1990.

Still referring to FIG. 22B, when the front end of the barrel 1956 is elevated (as illustrated in FIG. 22B), a force is applied to the locking block 1990, which compresses the cushion 1921. The compression of the cushion 1921 can be seen by comparing FIGS. 21A and 22B-the cushion 1921 is shown in a compressed state in FIG. 22B, and shown in a non-compressed state in FIG. 21A. It can be seen that, while the cushion 1921 is compressed, the locking block 1990 is spaced apart from the bottom of the pocket a different distance than it is spaced apart from the bottom of the pocket in FIG. 21A.

When the cushion 1921 is compressed, it produces a counter force opposing the downward force applied by the barrel lugs 1957. When the downward force is removed (because the firing cycle returns the barrel 1956 to the position shown in FIG. 21A), the cushion 1921, being a deformable spring material such as rubber, expands back to a non-compressed state (e.g., technically speaking it is a spring). This expansion returns the locking block 1990 to the state shown in FIG. 21A, where it is spaced apart from a bottom of the pocket a distance greater than it is spaced apart when the front end of the barrel is in its elevated position.

It is noted that the pocket in the metal frame, shown in FIG. 21A, may be deeper than the pocket used in firearms with polymer receivers. Alternatively, the pocket may be the same size and the locking block body 1990 may be smaller, to provide a gap between a bottom of the locking block and a bottom of the pocket. Another gap 1998, which may not be present in the known pocket, may be included as illustrated in FIG. 22C (this gap is empty, e.g., contains air).

Still referring to FIG. 22C, in this embodiment in which the locking block assembly includes the pin 1991 (e.g., a circular cross section pin), the slot 1992 may have a different shape, such as a capsule shape as illustrated. It can be seen by comparing FIG. 21A and FIG. 22C that the slot 1992 makes movement relative to the pin 1991 during the firing cycle.

To summarize, instead of the known slip fit pocket in a polymer receiver, a slip fit metal pocket with a gap for a deformable cushion may be provided. The slip fit metal pocket may be deeper at locations than the known slip fit polymer (and/or the locking block body may be smaller to provide to the gap). Instead of the locking block body, a locking block assembly including a locking block body and a deformable cushion may be provided. Such a locking assembly may allow a metal receiver to be used in place of a polymer receiver, with the original locking block body or a replacement locking block body (a replacement locking block that is smaller (e.g., less tall from bottom to top) than the original locking block body. This may be desirable for any of the following:

• • A retrofit of an existing firearm with a traditional polymer receiver, and/or
  • An original manufacture of a firearm with a metal receiver, and/or
  • A modular firearm similar to any modular firearm described herein, in which the modular firearm includes a frame and one or more grip parts, such as a trigger guard body, a grip part body, and/or a magazine funnel body.

Trigger Assembly

Any trigger assembly described herein may be similar in any respect to the FCU or other similar serialized components. It may include a body and one or more additional parts such as a trigger assembly and a rail (the rail may be separable from the body, however, this is not required—in other embodiments it may be possible and practical for a rail to be integrated with the body).

The body of the known FCU may include a pin hole, such as in an upper part of a rear of that body. This pin hole is used to retain the FCU to a non-serialized frame. In other words, a fastener such as a pin is used to fasten the FCU to the non-serialized frame. This fastening interface may be difficult for a user to disassembly (it may require at least a precisely-sized punch, and a hammer, to take out the pin-some less experienced user's may additionally need a table-mounted vice). Even where this fastening interface is not difficult for a user to disassemble, it may be possible for this fastener interface to loosen and/or wear over time.

In contrast, various embodiments described herein may not require that pin hole, and may be retained to a frame using one or more grip parts. In some embodiments, a grip part, such as a backstrap, may used to retain the trigger assembly to a non-serialized frame.

In various embodiments of a modular firearm, to attach the trigger assembly to the firearm, a user may insert the top part of a part into a space behind a body of the trigger assembly. The user may then pivot the grip part downwardly, into interlock these components. Another part, e.g., the funnel, may be slidingly attached to the firearm to secure the grip part.

For disassembly, the user may insert a tool (which may be an improvised tool such as a paperclip) into a tool access in a magazine funnel, to collapse a spring of the plunger assembly. This may allow the user to slide the magazine funnel off the firearm. With the magazine funnel removed, the user may pivot the grip part (e.g., the backstrap) oppositely the pivoting from installation.

This allows the backstrap to be removed from the space behind the body of the trigger assembly. With the grip part removed, the user may then separate the trigger assembly from the frame. A grip part usable to retain a serialized trigger assembly on a frame may be similar in any respects to the backstrap described in US Patent Publication No. 2024/0110767, which is incorporated by reference herein.

Trigger Guard

In various embodiments, a trigger guard may be integrated with the frame body, or may be part of another component. A non-exhaustive list includes:

• • A trigger guard integrated with a body of a frame housing/capturing the trigger assembly, and/or
  • A trigger guard that is not integrated with a body of the frame, but may be integrated with another part that is attachable to a body of a frame (e.g., may be integrated with a grip), and/or
  • A trigger guard that is a discrete part (e.g., not integrated with the frame or the grip).

When the trigger guard is not integrated with the frame, a body of the trigger guard may attach to the frame. A threaded part (e.g., a taper pin) may attach the body of the trigger guard to a body of the frame. A drive section of this threaded part may be accessible from a top of the frame.

It may be possible and practical to use a non-threaded additional part in place of the threaded additional part. For example, a spring-biased part, or any other additional part now known or later developed, may be used in place of the threaded additional part. In yet other examples, an additional part may not be required (e.g., the body of the trigger guard may attach to the body of the frame without requiring an additional part).

The trigger guard part may be used to retain the trigger assembly. By way of background, a front portion of a known FCU may attach to the body that contains the FCU (which may be called a body of the non-serialized frame). In such an approach, a front end of the known FCU may contain a pocket. A small metal projection in a bottom of a channel of the body of the non-serialized frame may be received by this pocket of the front end of the FCU. This may hold down the front end of the known FCU (e.g., hold it down relative to the body of the non-serialized frame that contains it).

An access port is provided in a body of the frame. The access port, which may alternatively be called a window, is the opening in the body of the frame.

A projection provided on the top of the frontmost part of the trigger guard (this projection may be called a tab) may extend through the access port, into the channel of the body of the frame. A space or pocket, between the tab and the top of the trigger guard, is also located in the channel of the body of the frame.

A frontmost part of the trigger assembly, which may be called a “front toe,” simply a projection, may fit into the space or pocket associated with the tab of the body of the trigger guard. With the tab extending through the access port, a user may slip the front toe/projection into the pocket. In various embodiments this may be done by 1) placing the trigger assembly in the channel of the body of the frame, and sliding it forward, 2) holding the trigger assembly at an angle while slipping the front toe into the pocket or space and then pivoting the trigger assembly downward to fully located its rear portion in the channel (where that rear portion can be secured by the backstrap).

Using the approach described above, to interlock the body of the trigger guard and the trigger assembly, may eliminate the need for the known interface of the additional small metal projection in a bottom of a channel of a body of a frame. This may reduce build cost, and may also improve build time (e.g., the cost and time to manufacture the body of the frame may be reduced compared to the cost and time to manufacture the body of the known frame with the small metal part to retain the trigger assembly). Also, the interlocking of the front toe with the pocket corresponding to the tab may be performed more easily by a user in the field, than the known attachment interface that involves the small metal tab (such as in poor lighting). The interlocking of the front toe with the pocket may also more securely retain the trigger assembly.

It is noted that the body of the trigger guard includes a female dovetail to receive a male dovetail of the main grip body, or a male dovetail of the frontstrap, but this may be reversed (so that the body of the trigger guard includes the male dovetail). A mag release/catch button may be included in a body of the trigger guard.

Front Grip Part (e.g., Frontstrap)

Similar to the backstrap, a separable frontstrap may come in different sizes, which allows a user to change the size of the grip of the firearm. For example, a user with small hands may prefer to replace a stock frontstrap with a thin and compact frontstrap, whereas a user with large hands may prefer to replace a stock frontstrap with a frontstrap having a large forward swell.

In the illustrated embodiments of the separable front strap, a front of the side grip panels and a back of the frontstrap may couple using a tongue and groove interface, as illustrated. In other embodiments, it may be possible and practical to reverse the tongue and groove interfaces, or to use some other attachment interfaces, now known or later developed, to couple the side grip panels and the frontstrap.

Magazine Funnel

Any magazine funnel described herein may be similar in any respect to any magazine funnel described in US Patent Publication No. 2024/0110767, which is incorporated by reference herein. In particular, it may interlock with any backstrap described herein in a similar way in which various magazine funnels described in the '767 application interlock with any backstrap (or other grip part) described in the '767 application.

As explained earlier, a backstrap may be tensioned. This is illustrated in FIGS. 3 and 5, wherein the backstrap is pivoted from the illustrated non-tensioned state into a tensioned state (as its pivoted to bring its bottom from the illustrated position toward the main grip part). With the backstrap in the tensioned state, a magazine funnel may be installed, and when installed may hold the backstrap in tension. The coupling of the magazine funnel and the backstrap also retains the magazine funnel on the modular firearm.

Side Grip Panels and Recoil Cushion

A back end of the side panels may me pocketed. These pockets may retain recoil cushions, which may be elastic (rubber) parts. When the backstrap is installed, the recoil cushions are sandwiched between the side paneling and the backstrap.

A size and dimension of the pocketing in the side grip panels can be selected to vary a magnitude of the force associated with the tensioned backstrap. For example, making the pockets gradually deepen along their length can be used to increase or decrease the magnitude of the force associated with a tensioned backstrap. Alternatively, the pockets can have uniform depth and the recoil cushions could have varying front-to-back thickness along their length, to increase or decrease the magnitude of the force associated with a tensioned backstrap. Either approach may perform a similar function as the small bump or other projection shown in FIG. 9B.

Trigger Assembly Frame

The part that houses and/or receives the trigger assembly may be a non-serialized part, which may be referred to as a trigger assembly frame or a non-serialized frame (since, traditionally the term “frame” has been used to indicate a serialized part). In various embodiments, the frame may include a number of frame features now known or later developed, such as a rail (shown on its front bottom) to attach firearm accessories such as a light module or some other rail-attachable accessory, a dust cover, or the like, or combinations thereof.

The frame may include the access port (described in the trigger guard section herein). In other embodiments, the frame may include any interface, now known or later developed, to interface with an interface of a front portion of the trigger assembly (also described in the trigger guard section described herein).

In the illustrated embodiments, a surface of the frame, which a surface of the backstrap is driven against, is part of the frame body. That projection, and the surface thereof, is shown in a number of figures, including FIG. 3. As mentioned earlier, in other embodiments it may be possible and practical for that surface, which the surface of the backstrap is driven against, to be part of an additional part that is fixably or removably coupled to the body of the frame.

To provide the possibility of utilizing known FCUs, some embodiments may anchor the additional part using the known FCU's hole for a safety lever pin. In other embodiments with the additional part, it may be attached to the body of the frame using any attachment interface or method, now known or later developed.

Rear Modular Grip Part (e.g., Backstrap)

Whereas a surface of an upper part of an underside of the backstrap is driven against the surface of the frame (as described in the trigger assembly frame section herein), clearance is provided to an adjacent part of the underside of the backstrap. For example, FIG. 5 emphasizes a gap between the underside of the backstrap 160 and a surface of a back of frame 110. The size of this gap is drawn for emphasis, not to scale. Given this gap, illustrated as clearance in FIG. 5, contact is isolated to upper and lower parts of the underside of the backstrap 160 (with clearance between an intermediary part of the underside of the backstrap 160).

Accordingly, the arrangement shown in FIG. 5 may be used to provide a tensioned backstrap. Alternatively, or in addition, other tensioning features such as a tensioning bump (described earlier herein), recoil cushions, or the like, may be provided to control a magnitude of the force associated with the tensioning.

Tensioned Grip Part

In the various illustrated embodiments, the tensioned grip part comprises a modular grip part-a backstrap. In other examples, a firearm may include a modular front grip part (e.g., a frontstrap, which allows a user to change grip sizes) to attach to a main grip part that does not include a backstrap (e.g., to a grip frame). For example, a firearm may have a front strap, but not a backstrap. In this case, the rear grip part may include the back and lateral sides of the grip (the frontstrap may include the front of the grip).

In these examples, the main grip part, to which the front grip part is attached, may include any of the backstrap features described herein. For example, the main grip part may include a surface drivable against a surface of a trigger assembly. The main grip part may be put in tension when the magazine funnel is installed (and/or put in tension when the front strap is installed).

Further, any of the modular firearm features described herein may be utilized in a firearm in which a rear of the grip is modular or non-modular. Also, any of the modular firearm features described herein may be used in a firearm with a non-modular grip.

EXAMPLES

It should be understood that it may be possible and practical to incorporate any feature in any of the illustrated embodiments into any other embodiment within the scope of the present disclosure. Here are some examples of that:

• • The interface on the lower part of the backstrap 1360 of FIG. 13, can be used in place of the interface on the lower parts of any grip parts described herein, including but not limited to the grip body frames shown in FIGS. 1-12. This could be done to make the earlier-described embodiments suitable for use with an integrated magazine funnel, or suitable for use with the magazine opening 1370 of FIG. 13.
  • Any of the illustrated features of FIGS. 1-18B may be used with an embodiment similar in any respect to any embodiment in which the serialized part is a frame. One example of such an embodiment is a modular firearm including frame and trigger assembly similar in any respect to frame 1993 and trigger assembly 1950, as well as any or all of:
    • A trigger guard similar in any respect to the trigger guard of FIG. 12 (or any other trigger guard body described herein),
    • A frontstrap similar in any respect to the frontstrap of FIG. 12 (or any other frontstrap body described herein).
    • Side panels and recoil cushions similar in any respect to the side panels and recoil cushions of FIG. 12 (or any other side panels and recoil cushions described herein), and/or
    • A magazine funnel similar in any respect to the magazine funnel of FIG. 12 (or any other funnel body described herein).
  • Any features of the locking block assembly illustrated in FIGS. 19A-B may be incorporated into any modular firearm that includes any features of any modular firearm embodiment described herein.

One or ordinary skill in the art will understand it may be practical and possible to combine any features described herein in any combination. The illustrated examples are provided for this purpose—not to constrain the disclosure.

Example 1 is an apparatus, comprising: a sequentially couplable set of two or more bodies, wherein the two or more bodies of the set are assemblable in a predefined order; the sequentially couplable set of two or more bodies including at least: a body to retain, to a frame of a firearm: 1) at least one grip part of one or more grip parts, or 2) a trigger assembly; and another body to retain the body in the firearm.

Example 2 is a kit of parts for a modular firearm, in which the kit of parts comprises a sequentially couplable set of two or more bodies, or includes at least one body of said set; wherein the two or more bodies of the set are assemblable in a predefined order; and said set includes at least: a body to retain at least one body to a frame of the firearm; and another body to retain the body in the firearm.

Example 3 includes the subject matter of example 2, or any other example herein, wherein the at least one body comprises a trigger assembly, and the apparatus further comprises a spring biased sliding part; wherein the body is retained using the spring biased sliding part, wherein the spring biased sliding part is biased along its direction of movement to cause engagement, and releasable or disengagable by a force from a direction opposite the biasing force.

Example 4 includes the subject matter of example 2, or any other example herein, wherein the at least one body comprises a trigger guard, a grip part, or a magazine funnel, and the apparatus further comprises a spring biased sliding part; wherein the body is retained using the spring biased sliding part, wherein the spring biased sliding part is biased along its direction of movement to cause engagement, and releasable or disengagable by a force from a direction opposite the biasing force.

Example 5 includes the subject matter of example 4, or any other example herein, wherein the at least one body comprises the grip part, the grip part comprising a grip frame; and the body comprises a backstrap.

Example 6 includes the subject matter of any of examples 2-3, or any other example herein, wherein the at least one body comprises a trigger assembly, and the kit of parts further comprises a part insertable into an opening, to retain the body to the frame; and wherein the insertable part does not contact the trigger assembly.

Example 7 includes the subject matter of any of examples 4-5, or any other example herein, wherein the at least one body comprises a trigger guard, a grip part, or a magazine funnel; the kit of parts further comprising a part insertable into an opening, to retain the body to the frame; and wherein the insertable part does not contact the frame.

Example 8 includes the subject matter of any of examples 1-7, or any other example herein, further comprising: a locking block pocket in the frame; a locking block assembly including a locking block and a deformable cushion; wherein the locking block pocket and the locking block are arranged to provide a gap between a bottom of the locking block pocket and a bottom of the locking block; wherein the deformable cushion is located in the gap.

Example 9 is a locking block assembly comprising: a locking block body, a locking block pocket in a body, wherein the locking block is locatable in the locking block pocket; a gap between a bottom of the locking block pocket and a bottom of the locking block body; and a deformable cushion located in the gap.

Example 10 includes the subject matter of example 8, or any other example herein, wherein the body is composed of a material that flexes differently than the material of a polymer receiver, during a firing cycle.

Example 11 includes the subject matter of any of examples 9-10, or any other example herein, wherein the body comprises a metal receiver.

Example 12 includes the subject matter of any of examples 9-11, or any other example herein, wherein the body is part of a modular firearm, the modular firearm including a frame, and one or more additional bodies including any of a trigger guard, a grip part, or a magazine funnel; wherein the body comprises the frame.

Example 13 includes the subject matter of any of examples 9-12, or any other example herein, wherein the locking block body includes a slot and a pin locatable in the slot.

Example 14 includes the subject matter of any of examples 9-13, or any other example herein, wherein the slot has a different shape than a cross section of the pin, in which the locking block body is movable relative to the pin along an axis that intersects the bottom of the locking block pocket.

Example 15 includes the subject matter of any of examples 9-14, wherein the pin has a circular cross section, and the slot has a non-circular shape, such as a capsule shape or other elongated shape.

Example 16 includes the subject matter of any of examples 9-15, wherein the deformable cushion comprises a rubber cushion.

We claim all modifications and variations coming within the spirit and scope of the following claims.

Claims

1. An apparatus, comprising:

a sequentially couplable set of two or more bodies, wherein the two or more bodies of the set are assemblable in a predefined order;

the sequentially couplable set of two or more bodies including at least: a body to retain, to a frame of a firearm: 1) at least one grip part of one or more grip parts, or 2) a trigger assembly; and another body to retain the body in the firearm.

2. An apparatus usable in a firearm, the apparatus comprising:

a kit of parts, wherein the kit of parts comprises a sequentially couplable set of two or more bodies, or includes at least one body of said set;

wherein the two or more bodies of the set are assemblable in a predefined order; and

said set includes at least: a body to retain at least one body to a frame of the firearm; and another body to retain the body in the firearm.

3. The apparatus of claim 2, wherein the at least one body comprises a trigger assembly, and the apparatus further comprises a spring biased sliding part;

wherein the body is retained using the spring biased sliding part, wherein the spring biased sliding part is biased along its direction of movement to cause engagement, and releasable or disengagable by a force from a direction opposite the biasing force.

4. The apparatus of claim 2, wherein the at least one body comprises a trigger guard, a grip part, or a magazine funnel, and the apparatus further comprises a spring biased sliding part;

wherein the body is retained using the spring biased sliding part, wherein the spring biased sliding part is biased along its direction of movement to cause engagement, and releasable or disengagable by a force from a direction opposite the biasing force.

5. The apparatus of claim 4, wherein the at least one body comprises the grip part, the grip part comprising a grip frame; and

the body comprises a backstrap.

6. The apparatus of claim 2, wherein the at least one body comprises a trigger assembly, and the kit of parts further comprises a part insertable into an opening, to retain the body to the frame; and

wherein the insertable part does not contact the trigger assembly.

7. The apparatus of claim 2, wherein the at least one body comprises a trigger guard, a grip part, or a magazine funnel;

the kit of parts further comprising a part insertable into an opening, to retain the body to the frame; and

wherein the insertable part does not contact the frame.

8. The apparatus of claim 2, further comprising:

a locking block pocket in the frame;

a locking block assembly including a locking block and a deformable cushion;

wherein the locking block pocket and the locking block are arranged to provide a gap between a bottom of the locking block pocket and a bottom of the locking block;

wherein the deformable cushion is located in the gap.

9. The apparatus of claim 2, wherein the body comprises a backstrap.

10. The apparatus of claim 9, wherein the other body comprises a magazine funnel.

11. The apparatus of claim 9, wherein the other body comprises a grip accessory.

12. The apparatus of claim 2, wherein the at least one body comprises a trigger assembly.

13. The apparatus of claim 12, wherein the kit of parts includes the trigger assembly or a part to anchor to a body of the trigger assembly.

14. The apparatus of claim 2, wherein the frame comprises the serialized component of the firearm, wherein the frame is configured to house or capture a non-serialized trigger assembly.

15. The apparatus of claim 2, wherein the kit of parts includes the frame.

16. The apparatus of claim 2, wherein the kit of parts further includes the body or the other body.

17. A fully or partially assembled firearm comprising the apparatus of claim 1, wherein the fully or partially assembled firearm comprises the firearm.

18. The apparatus of claim 1, wherein the body comprises a backstrap or other grip part.

19. The apparatus of claim 1, the body to retain the trigger assembly to the frame, wherein the trigger assembly comprises the serialized component of the firearm.

20. The apparatus of claim 1, the body to retain the at least one grip part of the one or more grip parts to the frame, wherein the frame comprises the serialized component of the firearm.

21. An apparatus usable in a firearm assembly, in which the firearm assembly includes a frame and one or more grip parts, the apparatus comprising:

a body to retain 1) at least one of the one or more grip parts to the frame, or 2) a trigger assembly to the frame;

the body is retained using a spring biased sliding part, wherein the spring biased sliding part is biased along its direction of movement to cause engagement, and releasable or disengagable by a force from a direction opposite the biasing force.

22. The apparatus of claim 21, wherein the at least one of the one or more grip parts comprises a backstrap.

23. The apparatus of claim 21, wherein the at least one of the one or more grip parts is arranged to contact a body of the trigger assembly.

24. An apparatus usable in a firearm assembly, in which the firearm assembly includes a frame and one or more grip parts, in which the frame is arranged to house or capture a trigger assembly, the apparatus comprising:

a body to retain at least one part to a frame; and

the body is retained using a part insertable into an opening, wherein the insertable part does not contact the at least one part.

25. The apparatus of claim 24, the body having more than one function, including 1) the retention function, and 2) another function, the other function employed by an operator when operating the firearm.

26. The apparatus of claim 24, the at least one part comprises the trigger assembly.

27. The apparatus of claim 24, wherein the at least one part comprises a grip part of the one or more grip parts, wherein the body comprises another grip part of the one or more grip parts.

28. The apparatus of claim 27, wherein the grip part comprises a grip frame, and the body comprises a backstrap.

29. The apparatus of claim 24, wherein the at least one part comprises a trigger guard, a grip part of the one or more grip parts, or a magazine funnel.

30. The apparatus of claim 24, wherein the apparatus further comprises a spring biased sliding part;

wherein the body is retained using the spring biased sliding part, wherein the spring biased sliding part is biased along its direction of movement to cause engagement, and releasable or disengagable by a force from a direction opposite the biasing force.