Adjustable firearm gas block

Abstract

An adjustable gas block may include an ingress port to receive gas expelled from a gas port located on a firearm barrel, and a front end to receive a gas metering screw, wherein the gas metering screw is drivable into a threaded hole in the front end to at least partially cover the ingress port with an end of the gas metering screw to restrict a flow of the gas, according to various embodiments. In some embodiments, a columnar sidewall of the head of the gas metering screw may include a circumferential marking alignable with an alignment feature of the front end of the adjustable firearm gas block to set a predefined gas flow restriction. In some embodiments, the adjustable gas block may include a columnar projection with a section alignable with an individual one of the indentations or bumps to preserve a rotational position of the gas metering screw.

Description

BACKGROUND

Typical firearms propel a bullet or other type of projectile through the expansion of gas within a firearm barrel. The majority of the gas may be expelled out of the front of the firearm barrel together with the bullet. However, some firearms may exploit a portion of the gas to automatically cycle the action of the firearm (e.g., “charge” the firearm), which may include ejecting the used casing and reloading another round of ammunition into the firing chamber. This portion of the gas may be expelled from a gas port located on the barrel. The expelled gas may be channeled by a gas tube back to the upper receiver so that it may be used to “charge” the firearm.

Some firearms may have a gas block located on the barrel to connect the gas port located on the barrel to the gas tube. This gas block, if positioned in a correct location on the length of the barrel during firearm assembly, and in a correct angular orientation, may prevent gas leaks and ensure that a sufficient amount of gas enters the tube to drive the action of the firearm. If the gas block is not positioned on the correct location or in a correct angular orientation during firearm assembly, an ingress port on an interior of the gas block may be partially misaligned with the gas port located on the barrel. This partial misalignment may reduce the amount of gas entering the gas tube, which could cause other firearm components to regularly or intermittently cycle incorrectly when fired (leading to regular or intermittent jams during firing). Since the gas block covers the gas port located on the barrel, both the gas port and the ingress port on the interior of the gas block are hidden from view once the gas block is slipped over the barrel, which makes positioning the gas block in the correct angular orientation difficult.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a timing system for a firearm gas block, according to various embodiments.

FIG. 2 illustrates a view of the timing system of FIG. 1 in which the gas block has been pulled away from the shoulder, according to various embodiments.

FIG. 3 illustrates a top view of the timing system of FIG. 1, according to various embodiments.

FIGS. 4A-B illustrate sectional top views of one embodiment of an adjustable firearm gas block in which the adjustable firearm gas block is arranged for use with the firearm barrel assembly described with respect to FIGS. 1-3.

FIG. 5 illustrates a front view of the adjustable firearm gas block of FIG. 4.

FIG. 6A illustrates a front end view of the adjustable firearm gas block of FIGS. 1-4, and FIG. 6B illustrates a cross-sectional view taken along section line F of FIG. 6A.

FIG. 7A is a front view of another embodiment of an adjustable firearm gas block.

FIG. 7B is a perspective view showing visual indicators on a sidewall of a head of the gas block screw of the adjustable firearm gas block shown in FIG. 6B.

DETAILED DESCRIPTION

Timing System for Firearm Gas Block

A shoulder may be formed behind a location for a gas block by selectively removing material when the barrel is machined, and this shoulder fixes the position of the gas block in the lengthwise position. However, known shoulders do not prevent mistiming the gas block (say, a wrong angular orientation in which gas flow is significantly impeded). As a result, firearm manufacturers may use a tool called a jig to time the gas block (to achieve the required orientation). When using the jig, the barrel is installed in the upper receiver, and then the jig is used to position the gas block relative to the upper receiver (the jig is used to time the gas block). With the gas block timed, pinning holes can then be drilled through the gas block and partially into the barrel, pins can be inserted into the pinning holes, so that the position of the gas block is fixed before removing the jig.

The use of the jig to time the gas block requires significant additional labor to assemble the firearm, raising manufacturing costs. One jig-less manufacturing method uses screws in place of pins. An attempt is made to predrill shallow template “dimple” in the barrel (on the gas block journal on which the gas block is to be slide over) before sliding on the gas block. The challenge comes from trying to align screw tips of screws used to fasten the gas block to the barrel into the predrilled shallow holes in barrel without the benefit of sight. Without experience on the part of the installer, due to the lack of visibility in attempting to find a template obscured by the gas block, a person could mistake the screw tip biting into the surface of the barrel for finding the template, and thus secure the gas block in a misoriented position.

FIG. 1 illustrates a timing system for a firearm gas block, according to various embodiments. FIG. 2 illustrates of view of the timing system of FIG. 1 in which the gas block has been pulled away from the shoulder. Although this particular example is for an AR15, it should be appreciated that any of the features illustrated or described herein may be used in any firearms having gas-operation systems (including direct impingement systems, piston-driven systems, and any other gas operation system now known or later developed). FIG. 3 illustrates a top view of the timing system of FIG. 1.

Referring now to FIG. 2, the timing system includes the timing notch 11 located on the shoulder and the timing boss 21 located on the end of the gas block 20. The timing notch 11 may be formed by selectively machining the barrel or the shoulder, for example, by recessing the planar surface of the shoulder using a milling cutter. In the illustrated example, the timing notch 11 may be formed by recessing the shoulder. The timing boss 21 may be formed by selectively machining the gas block 20.

The timing system including the timing notch 11 and the timing boss 21 is for timing the gas block 20, and may be independent from fasteners used to secure the gas block 20 once timed. Any known fasteners (not shown) may be used in combination with any gas block using the timing system (such as set screws located at the bottom of the gas block 20 (not shown) to pull the bore of the gas block against the barrel). The timing system may also be independent from the illustrated hole 1 on the side of the gas block (this hole 1 is for pinning the end of a gas tube (not shown) into the gas block at the large hole 2 shown in the illustration).

Referring now to FIGS. 1 and 3, when the timing boss 21 is located in the timing notch 11 as shown, the gas block 20 is in the correct rotational orientation to position an ingress port on the interior of the gas block 20 over the gas port 12 (FIG. 2, the gas port 12 located on the barrel) with no misalignment.

Unlike the use of a template and screws, the timing system is independent of the fasteners used (so an operator need not have the expertise to feel the difference between a template and a screw biting into a barrel). The timing notch 11 and the timing boss 21 may be integrally formed as part of the shoulder and the gas block, respectively, hence fastener parts like pins required to time the gas block in some other systems may not be required.

In the illustrated embodiment, the timing boss 21 may be dimensioned so that the tip of the timing boss 21 does not contact the closed end of the timing notch 11 (a small gap 15 is shown between the tip of the timing boss 21 and the closed end of the timing notch 11). In this example only the sides of the timing boss 21 may make contact, as shown in more detail in FIG. 3 (the timing boss 21 may have a width arranged to fit into the timing notch 11 and a height selected to form the gap 15 when the timing boss 21 is in the timing notch 11). The gap 15 may be provided to ensure that the gas block 20 contacts the shoulder (such contact provides alignment in the lengthwise direction). However, in other embodiments, the sides and tip of the timing boss 21 may contact the timing notch 11. For instance, in one embodiment, the shoulder may be cut with long shallow notches to form a wavy surface defining timing indentations around the shoulder. In such an embodiment, the end of the gas block may be cut similarly to form wide timing protrusions to fit in the timing indentations.

In other embodiments, the barrel may not include a shoulder. The barrel can be selectively machined to leave an integrated projection (such as a column, post, or the like) that fixes a position of a gas block in the linear direction and is wide enough to cut a timing notch. In this embodiment, the sides and tip of the timing boss may make contact with the timing notch (that is cut into the projection) to fix the position of the gas block in the linear direction and angular orientation.

In yet further examples, the integrated projection of the barrel may form a timing protrusion (such as a timing boss) and a timing indentation may be cut into the end of the gas block.

The gas block shown in the figures does not include a slit. Some gas blocks may include a slit (say at the bottom of the gas block) to allow the gas block to expand to slide onto the journal. Fasteners may close the slit to clamp the gas block onto a journal of the barrel. Any timing system described herein may be used with this type of gas block, or any other type of gas block available today, or later developed. Any timing system described herein may be used in combination with any adjustable firearm gas block described herein or designed in U.S. Provisional Patent Application 62/861,827 (filed Jun. 14, 2019) and U.S. patent application Ser. No. 16/900,161 (filed Jun. 12, 2020), each of which is incorporated by reference herein.

In one example, a barrel assembly for a firearm is provided. The barrel assembly may include a barrel having a gas port and a shoulder or other projection; a gas block around the barrel and covering the gas port, wherein an end of the gas block faces the shoulder of the barrel or the other projection of the barrel; and a timing system including a timing protrusion and a timing indentation, the timing system to rotationally orient the gas block to position an ingress port of the gas block over the gas port (located on the barrel) when the timing protrusion is positioned in the timing indentation, wherein one of the timing protrusion and the timing indentation is formed at the end of the gas block and the other one of the timing protrusion and the timing indentation is formed at the shoulder of the barrel or the other projection of the barrel.

In one example of this barrel assembly, the timing indentation comprises a single timing notch and the timing protrusion comprises a single timing boss.

In one example of this barrel assembly, the timing protrusion is integrally formed on the end of the gas block.

In one example of this barrel assembly, the timing indentation comprises a cut into a side of the shoulder of the barrel or the other projection of the barrel.

In one example of this barrel assembly, the barrel assembly may further include one or more fasteners to pull the bore of the gas block against a journal of the barrel, wherein the timing system is separate from the fasteners. In one example, the one or more fasteners are installed on a first side of the barrel, and wherein the timing system is located on a second opposite side of the barrel.

In one example of this barrel assembly, the gas block defines a slit, and wherein the one or more fasteners close the slit to clamp the gas block onto a journal of the barrel.

In one example of this barrel assembly, the shoulder of the barrel or the other projection of the barrel includes a surface that makes contact with a surface of the end of the gas block when the timing protrusion is positioned in the timing indentation, wherein the timing indentation comprises a hole formed in one of the surfaces.

In one example of this barrel assembly, the barrel assembly includes a gap located between a tip of the timing protrusion and an end of the timing indentation when the surfaces are in contact.

In one example, a firearm is provided. The firearm may include a barrel having a gas port and a shoulder or other projection; a gas block around the barrel and covering the gas port, wherein an end of the gas block faces the shoulder of the barrel or the other projection of the barrel; and a timing system including a timing protrusion and a timing indentation, the timing system to rotationally orient the gas block to position an ingress port of the gas block over the gas port (located on the gas barrel) when the timing protrusion is positioned in the timing indentation, wherein one of the timing protrusion and the timing indentation is formed at the end of the gas block and the other one of the timing protrusion and the timing indentation is formed at the shoulder of the barrel or the other projection of the barrel. In one example, the firearm comprises an AR-15.

In one example of this firearm, the timing indentation comprises a single timing notch and the timing protrusion comprises a single timing boss.

In one example of this firearm, the timing protrusion is integrally formed on the end of the gas block.

In one example of this firearm, the timing indentation comprises a cut into a side of the shoulder of the barrel or the other projection of the barrel.

In one example of this firearm, the firearm may further include one or more fasteners to pull an underside of the gas block against a journal of the barrel, wherein the timing system is separate from the fasteners. In one example, the one or more fasteners are installed on a first side of the barrel, and wherein the timing system is located on a second opposite side of the barrel.

In one example of this firearm, the gas block defines a slit, and wherein the one or more fasteners close the slit to clamp the gas block onto a journal of the barrel.

In one example of this firearm, the shoulder of the barrel or the other projection of the barrel includes a surface that makes contact with a surface of the end of the gas block when the timing protrusion is positioned in the timing indentation, wherein the timing indentation comprises a hole formed in one of the surfaces. In one example, the firearm further includes a gap located between a tip of the timing protrusion and an end of the timing indentation when the surfaces are in contact. In one example, the surfaces comprise planar surfaces.

Adjustable Firearm Gas Block

A user may desire to restrict the flow of gas from a gas port 12 (FIG. 2) into the gas tube, e.g., a gas tube installed into the opening 2 (FIG. 2) at the end of the gas block 20 (FIG. 2). The performance advantages of restricting this gas flow are known, such as to compensate for the user of a suppressor and/or to modify the performance of the firearm. As is known, this gas flow can be reduced down to the minimal level needed to automatically cycle the firearm or reduced down even further in which case the user will manually cycle the firearm.

A known adjustable firearm gas block is described in U.S. Pat. No. 9,410,756. In the known adjustable firearm gas block, an adjustment screw is tightened down a user-selectable amount to reduce the gas flow as desired. To keep the adjustment screw from unintentionally rotating again after selecting a position, an axial groove is provided in the threaded section of the adjustment screw. A detent plunger may engage this axial groove in various rotational positions of the axial screw. This arrangement requires a number of individual components—a detent slot for the leaf spring, a fastener to hold down one end of the leaf spring, a detent bore for holding the detect plunger between the adjustment screw and the other end of the leaf spring.

Various known adjustable firearm gas blocks are cost prohibitive to manufacture and/or suffer other drawbacks. An improved gas block may reduce manufacturing costs and/or provide other benefits compared to known adjustable firearm gas blocks.

FIG. 4A illustrates a sectional top view of one embodiment of an adjustable firearm gas block 300 in which a section of the gas block above a centerline of a gas metering screw 31 has been removed. FIG. 4B illustrates another sectional top view in which a head 41 of the gas metering screw 31 and a head 42 of a spring pin 32 above a centerline of the heads 41 and 42 are also similarly sectioned. Since this embodiment of an adjustable firearm gas block is arranged for use with the barrel assembly described with respect to FIGS. 1-3, the timing boss 21 (FIG. 2) is present in this embodiment. It should be appreciated that any adjustable firearm gas block features described herein can be used in any known barrel assembly whether or not that barrel assembly includes any of timing system features described with respect to FIGS. 1-3.

The adjustable firearm gas block 300 includes a gas metering screw 31 having a head 41 drivable to position an end 45 of the gas metering screw 31 into a channel over the ingress port 35, which impedes the flow of gas from the gas port 12 (FIG. 2) to a gas tube inserted in the opening 2 (FIG. 2). A spring pin 32 has a head 42 that makes contact with the head 41 of the gas metering screw 31.

The head 41 has a plurality of indentations 43 and areas between the indentations 43. When the head 42 makes contact with the area between the indentations 43, the spring pin 32 is not relaxed. When the head 42 is aligned with one of the indentations 43, the spring pin 32 may relax (e.g., completely relax in some embodiments). FIG. 5 illustrates a front view in which a pointed tip 51 of the spring pin 32 is shown in one of the indentations 43.

In this example, the plurality of indentations 43 are formed by removing material from a cylindrical sidewall of the head 41. In other examples, a sidewall of a head of a gas metering screw may have bumps formed therein. In such an example, a sidewall of the head of a spring pin may have a gap to mate with the bumps. No force (or a small force) may be applied to the head of the gas metering screw (by the head of the spring pin) when an individual one of the bumps is positioned in the gap. A larger force may be applied to the head of the gas metering screw (by the head of the spring pin) when there is no alignment of any of the bumps with the gap. Although the sidewall of the head 41 is cylindrical in this embodiment, in other embodiments the sidewall may have any number of flats (such as hexagonal column shape in one example). In examples in which the sidewall has flats, the vertex (where the flats meet) may be the “bumps” that interface with an indentation on the spring head.

In one example in which the spring pin 32 (FIGS. 4A-B) may be completely relaxed when the pointed tip 51 of the head 42 is aligned with the one of the indentations 43, the indentations 43 may be deeper than a height of the pointed tip 51. This may allow the pointed tip 51 to be located in a void of one of the indentations 43 without any contact of the top of the pointed tip 51 and the bottom of the void. This may allow the spring pin 32 to completely relax, which may increase longevity. This feature may allow a very slight rotational movement of the gas metering screw 31 when aligned, which gives a user feedback that alignment has been achieved (and in the middle of this slight rotational range there may be zero contact between the heads 41 and 42). In such an example, the slope of the pointed tip 51 may be linear and the slope of the indentations 43 may be non-linear (e.g., curved), although such a feature may not be required to provide the user feedback (the slopes can be the same if the void is larger than the pointed tip 51).

Referring again to FIGS. 4A-B, the system 300 may be arranged to fully obstruct the channel over the ingress port 35 with the end 45 of the gas metering screw 31. In this state, an end 91 of the head 41 may align with an alignment feature (such as an end 92 of the head 42 of the spring pin 32) to indicate to the user that the channel over the ingress port 35 is fully obstructed. Also, in various embodiments, the head 41 may have circumferential markings 49 (e.g., indentations or bumps in other examples). In the case of more than one indentation, an innermost one of the circumferential markings 49 (e.g., indentations or bumps in other examples) may align with the alignment feature (e.g., the end 92 of the head 42) in the fully open position (as illustrated). Another one of the circumferential markings 49 (e.g., the indentations or bumps in other examples) may align with the alignment feature (e.g., the end 92 of the head 42) in a state between fully open and fully closed, e.g., half open in the present example. In this example, the end 92 of the head 42 of the spring pin 32 is a planar face and the end 91 of the head 41 of the gas metering screw 31 is a planar face, however, this is not required (in other examples, an end of the spring pin 32 may be a curved face or some other end and/or the end of the gas metering screw 31 may be a curved face or some other end).

Also, in this example, the adjustable firearm gas block includes the spring pin 32. In other examples, an adjustable firearm gas block may include the gas metering screw 31 and some other mechanism (e.g., now known of later developed) to preserve the rotational position of the gas metering screw 31. This mechanism may include a columnar projection extending from a front face of the adjustable firearm gas block 300 (similar to how spring pin 32 extends from the front face), or may be any other mechanism behind the front face of the adjustable firearm gas block 300 (e.g., at least partially inside the adjustable firearm gas block 300). In various embodiments, the alignment feature may be an end of the columnar projection or the front face of the adjustable firearm gas block.

Referring again to FIG. 5, the end 91 of the head 41 may include a reference marking 59 such as an indentation (or bump in some other example) alignable with a predefined reference to aid a user in tracking the position of the gas metering screw 31. In this example, the predefined reference is the pointed tip 51. However, in other examples, the predefined reference can be some other projection, indentation, or marking on a side or end of the head 42 of the spring pin 32. A user may count “clicks” from alignment of this reference marking 59 with the predefined reference for fine adjustment tracking (together with the course adjustment tracking described with reference to FIGS. 4A-B) as the user tries different gas restriction settings.

In some examples, optionally, a position of the gas metering screw 31 may be timed in the threaded hole so that alignment of the reference marking 59 with the predefined reference coincides with optimal alignment of the circumferential marking 49 with the alignment feature. In this way, a user can judge whether one of the circumferential markings 49 is exactly aligned with the alignment feature (e.g., in the illustrated example the end 92 of the head 42 of the spring pin 32). However, timing the position of the gas metering screw 31 is not required in various embodiments.

According to variously described examples above, the predefined reference is part of the head 42 of the spring pin 32 (e.g., part of the sidewall of the spring pin 32). In other examples, the predefined reference may be a mark on the end 92 of the head 42 of the spring pin 32, or a mark on the face of the front end of the adjustable firearm gas block 300 in embodiments without a columnar projection such as the spring pin 32.

Referring to FIGS. 4A-B and 5 in combination, it may be possible in some examples for a user to grip the head 41 (aided by the indentations 43 the indentations of the circumferential markings 49 in some examples) for tool-less adjustment of the gas metering screw 31. In any event, in the illustrated embodiment a user may use a hex wrench in the hex socket illustrated on the end 91 of the head 41 in FIG. 5. In other examples, any other type of drive mechanism can be used (e.g., some other type of socket and or wrench). In example in which the head 41 has any number of flats (such as a hexagon columnar shape as one example), the head 41 may be sized to mate with a wrench to drive the head 41 (the wrench may receive the hexagonal columnar shaped head 41).

Referring again to FIGS. 4A-B, a seal 60 may be formed by a smooth section of the gas metering screw 31 and a smooth hole at the bottom of the threaded hole. The seal 60 is maintained in any selected position of the gas metering screw 31. This seal 60 may prevent gas and/or debris carried by the gas from reaching the threading of the gas metering screw 31. This may keep the threading clean so that the gas metering screw 31 does not seize up after prolonged use. In this example, the smooth hole at the bottom of the threaded hole has the minor diameter of the threads; however, in other examples the diameter of the smooth hole may be smaller than the minor diameter of the threads. This view also illustrates the interference fit of the mounting section of the spring pin 32.

FIG. 6A illustrates a front end view of the adjustable firearm gas block of FIGS. 1-4, and FIG. 6B illustrates a cross-sectional view taken along section line F of FIG. 6A. Referring to FIG. 6B, when the ingress port 35 is not completely covered, gas travels to the opening 62 where it may enter an opening of a gas tube (not shown) installed in the large hole 2. The hole 1 (FIG. 1) for pinning the gas tube is also shown in this view.

FIGS. 7A and 7B illustrate a front view and a perspective view, respectively, of another embodiment similar in any respect to the adjustable firearm gas block described with reference to FIGS. 4A-6B. In this embodiment, the head 41 of the spring pin 32 has no cut away (e.g., no pointed tip). The slope of the plurality of indentations on the head 41 of the gas metering screw 31 is shallower than the slope of the indentations in the embodiment described with reference to FIGS. 4A-6B (also each indentation is wider). This embodiment still provides one indentation every 45 degrees, but it may be possible and practical to provide more indentations (if desired) using the approach described with respect to the embodiment described with respect to FIGS. 4A-6B.

It may be possible to keep the spring pin in a fully resting state when aligned with the indentations in either embodiment; however, this is not required. In other embodiments, the spring pin may apply less force to the gas metering screw in some rotational positions than other rotational positions. In either case, the adjustable firearm gas block still may give a user a clicking feedback associated with finite rotational positions between intermediary positions.

Any adjustable firearm gas block described herein may be used in the barrel assembly described with reference to FIGS. 1-3, or any known barrel assembly or later developed barrel assembly. Referring to FIGS. 4A-6B, the adjustable firearm gas block may be manufactured without the timing boss for use with known barrel assemblies, e.g., mil spec barrel assemblies. Likewise, the barrel assembly described with reference to FIGS. 1-3 may be manufactured with the adjustable firearm gas block features described herein, any other adjustable firearm gas block features known or later developed, or any other gas block features (such as on a standard non-adjustable firearm gas block).

Although various adjustable firearm gas blocks described with reference to FIGS. 4A-7B utilize a self-retaining spring pin, this is not required. Other embodiments may utilize some other structure with a section to make contact with the head of an adjustable firearm gas block. These pieces may protrude from the adjustable firearm gas block so that a position may be visually indicated to a user (in addition to any audible “clicking” indication provided by the structure moving into and out of indentations on the head of the gas metering screw). Other structures, self-retaining or otherwise, may be used to selectively release a force on a head of the gas metering screw at different rotational positions of the gas metering screw (the force is applied on the gas metering screw at intermediary rotational positions between the rotational positions).

Although various embodiments described with respect to FIGS. 4A-7 are for an AR15, it should be appreciated that any of the adjustable gas block features illustrated or described herein may be used in any firearms having gas-operation systems (including direct impingement systems (which may use a gas tube similar to the gas tube described herein), piston-driven systems, and any other gas operation system now known or later developed).

Having described and illustrated various examples herein, it should be apparent that other examples may be modified in arrangement and detail. We claim all modifications and variations coming within the spirit and scope of the following claims.

Claims

1. An adjustable firearm gas block, comprising: an ingress port to receive gas expelled from a gas port located on a barrel of a firearm; anda threaded hole to receive a gas metering screw, wherein the gas metering screw is drivable into the threaded hole to at least partially cover the ingress port with an end of the gas metering screw to restrict a flow of the gas, wherein a head of the gas metering screw has an end and a columnar sidewall, wherein the columnar sidewall defines a plurality of indentations or a plurality of bumps; andan additional hole to receive a single fixably mounted length of a spring pin, wherein the spring pin includes a remaining length and at least part of the remaining length is configured to selectively flex or bend away from the gas metering screw in response to rotation of the gas metering screw, wherein the remaining length of the spring pin includes a section alignable with an individual one of the indentations or bumps, wherein when the section of the spring pin is aligned with an individual one of the indentations or bumps a rotational position of the gas metering screw is preserved.

2. The adjustable firearm gas block of claim 1, wherein the spring pin is arranged to contact the gas metering screw at only the columnar sidewall of the head of the gas metering screw.

3. The adjustable firearm gas block of claim 1, wherein the spring pin is in a resting state in the case that the section of the spring pin is aligned with the individual one of the indentations or bumps.

4. The adjustable firearm gas block of claim 1, wherein the section of the spring pin comprises a cylinder shaped head.

5. The adjustable firearm gas block of claim 1, wherein the section of the spring pin defines: a V-shaped projection with sloped sidewalls to urge a top of the V-shaped projection to a bottom of the individual one of the indentations in the case that the section of the spring pin is aligned with the individual one of the indentations, oran indentation, wherein each of the bumps is shaped to urge a top of the individual bump to a bottom of the indentation of the section of the spring pin in the case that the section of the spring pin is aligned with the individual one of the bumps.

6. The adjustable firearm gas block of claim 1, wherein the end of the head of the gas metering screw comprises a means for driving the gas metering screw into the threaded hole.

7. The adjustable firearm gas block of claim 1, wherein the end of the gas metering screw is aligned with an end of the section of the spring pin in the case that the gas metering screw is positioned for maximum gas restriction.

8. The adjustable firearm gas block of claim 7, wherein the columnar sidewall of the head of the gas metering screw includes a circumferential marking to align with the end of the section of the spring pin in the case that the gas metering screw is positioned for minimum gas restriction.

9. The adjustable firearm gas block of claim 8, wherein the columnar sidewall of the head of the gas metering screw includes one or more additional circumferential markings individually alignable with the end of the section of the spring pin to indicate one or more other positions, respectively, of the gas metering screw.

10. The adjustable firearm gas block of claim 1, wherein in the case the section of the spring pin is not aligned with any of the indentations or bumps: the section of the spring pin is in contact with the area between two of the indentations or bumps, andthe spring pin applies a force that is greater than any force applied by the spring pin in a case that the section of the spring pin is aligned with the individual one of the indentations or bumps.

11. The adjustable firearm gas block of claim 1, wherein the threaded hole comprises a smooth hole below the threads, wherein an end of the gas metering screw has a smooth section to sealingly couple with the smooth hole to prevent gas and/or debris carried by the gas from reaching the threads.

12. The adjustable firearm gas block of claim 11, wherein at least a portion of the smooth hole is arranged to remain in contact with at least a portion of the smooth section of the gas metering screw while the gas metering screw is driven from a first position associated with one of maximum or minimum gas restriction to a second position associated with the other of maximum or minimum gas restriction.

13. The adjustable firearm gas block of claim 1, wherein the single fixably mounted length of the spring pin is sized to retain the single fixably mounted length of the spring pin in the additional hole by an interference fit, wherein the spring pin is self-retaining and fastened to the gas block using only the single fixably mounted length of the spring pin.

14. An apparatus, comprising: an adjustable firearm gas block including:an ingress port to receive gas expelled from a gas port located on a barrel of a firearm;a threaded hole to receive a gas metering screw, wherein the gas metering screw is drivable into the threaded hole to at least partially cover the ingress port with an end of the gas metering screw to restrict a flow of the gas; andmeans for selectively releasing a force on a head of the gas metering screw at different rotational positions of the gas metering screw, wherein said force is applied on the gas metering screw at intermediary rotational positions between the rotational positions; andan additional hole to receive a single fixably mounted length of the selective force releasing means, wherein the selective force releasing means includes a remaining length and at least part of the remaining length is configured to selectively flex or bend away from the gas metering screw in response to rotation of the gas metering screw, wherein the remaining length of the selective force releasing means includes a section alienable with part of the gas metering screw in the rotational positions to preserve a current rotational position of the gas metering screw.

15. The apparatus of claim 14, further comprising means for visually delineating at least some of the rotational positions associated with the selectively released force differently than the intermediary rotational positions between the rotational positions.

16. The apparatus of claim 15, wherein the threaded hole comprises a smooth hole at a bottom of the threaded hole, wherein an end of the gas metering screw has a smooth section to sealingly couple with the smooth hole to prevent gas and/or debris carried by the gas from entering the threaded hole.

17. The apparatus of claim 14, wherein the selective force releasing means comprises a spring pin adjacent to the gas metering screw.

18. The apparatus of claim 17, wherein the spring pin is arranged to periodically contact the part of the gas metering screw as the gas metering screw is rotated from one of the rotational positions associated with one of maximum or minimum gas restriction to one of the rotational positions associated with the other of maximum or minimum gas restriction.

19. The apparatus of claim 18, wherein the part of the gas metering screw comprises a sidewall of a head of the gas metering screw.

20. The apparatus of claim 14, further comprising a firearm including: the barrel having the gas port located thereon;wherein the adjustable firearm gas block is mounted around the barrel covering the gas port located on the barrel.

21. The apparatus of claim 20, wherein the barrel includes a shoulder or other projection, wherein an end of the adjustable firearm gas block faces the shoulder of the barrel or the other projection of the barrel; wherein the firearm further includes a timing system including a timing protrusion and a timing indentation, the timing system to rotationally orient the adjustable firearm gas block to position the ingress port of the adjustable firearm gas block over the gas port located on the barrel when the timing protrusion is positioned in the timing indentation, wherein one of the timing protrusion and the timing indentation is formed at the end of the adjustable firearm gas block and the other one of the timing protrusion and the timing indentation is formed at the shoulder of the barrel or the other projection of the barrel.

22. An adjustable firearm gas block, comprising: an ingress port to receive gas expelled from a gas port of a barrel of a firearm;a front end to receive a gas metering screw, wherein the gas metering screw is drivable into a threaded hole inside the adjustable firearm gas block to at least partially cover the ingress port with an end of the gas metering screw to restrict a flow of the gas, wherein a head of the gas metering screw has an end and a columnar sidewall, wherein the columnar sidewall defines a plurality of indentations or a plurality of bumps; andwherein the columnar sidewall of the head of the metering screw includes a circumferential groove or circumferential protrusion around the columnar sidewall to define a degree of restriction of the ingress port, the circumferential groove or circumferential protrusion alignable with an alignment feature of the front end of the adjustable firearm gas block to set a predefined gas flow restriction.

23. The adjustable firearm gas block of claim 22, wherein the predefined gas flow restriction comprises minimum selectable restriction of the flow of the gas.

24. The adjustable firearm gas block of claim 22, wherein the columnar sidewall of the head of the gas metering screw includes an additional circumferential groove or circumferential protrusion around a different part of the columnar sidewall to define a different degree of restriction of the ingress port, the additional groove or circumferential protrusion alignable with the same alignment feature to set the adjustable firearm gas block to a different predefined gas flow restriction.

25. The adjustable firearm gas block of claim 22, wherein the alignment feature comprises a face of the front end of the adjustable firearm gas block.

26. The adjustable firearm gas block of claim 22, wherein the alignment feature comprises an end of a columnar projection extending from a face of the front end of the adjustable firearm gas block.

27. The adjustable firearm gas block of claim 26, wherein the columnar projection comprises part of a length of a spring pin.

28. The adjustable firearm gas block of claim 22, wherein the end of the head of the gas metering screw comprises a marking alignable with a predefined reference, the marking on the end of the head of the gas metering screw usable to track a rotational position of the gas metering screw from the position in which the circumferential marking is aligned with the alignment feature.

29. The adjustable firearm gas block of claim 28, wherein the predefined reference comprises: an indentation or projection formed on the sidewall of the columnar projection, ora marking on a face of the front end of the adjustable firearm gas block or on an end of the columnar projection.

30. The adjustable firearm gas block of claim 28, wherein a position of the gas metering screw is timed in the threaded hole so that alignment of the marking on the end of the head of the gas metering screw with the predefined reference coincides with optimal alignment of the circumferential marking with the alignment feature.