Rifle Upper Receiver Components

Description

PRIORITY CLAIM AND CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit under 35 U.S.C. § 119(e)(1) of U.S. Provisional Application No. 63/718,998, filed Nov. 11, 2024, which is hereby incorporated by reference in its entirety.

BACKGROUND

There are tens of millions of AR styled rifles (including AR-15, M16, M4, etc.) in America today. With the western-trained allies also using AR styled rifles, the AR styled rifle is one of, if not the most prolific rifle in the world. The manufacture and sales of AR styled rifles represents a 10 billion dollar per year industry, with most firearms manufacturers around the world producing and/or marketing a version of an AR styled rifle.

AR styled rifles are produced to use various sizes of cartridges, including. 223/5.56 mm NATO, 22-LR, 9×19 mm Parabellum, various shotgun calibers, as well as others, including 7.62×39 mm rounds. The 7.62×39 mm cartridge is a rimless cartridge that was designed by the Soviet Union during World War II for the SKS and AK-47 rifles and others, and has since proliferated throughout the world, being widely used by civilians and militaries nearly everywhere. The use and production of the 7.62×39 mm cartridge in many developing nations means that the manufacturing quality for cartridges produced in the regions can vary by a significant margin. Variations can include the forces produced by the ignited cartridge, including the amount and pressure of the resulting gases.

Using an AR styled rifle reduces or eliminates weapons training for persons familiar with the AR styled rifle (such as Western-trained military personnel, for example). As military and specialized operations can take place anywhere in the world, there is a need for an AR styled rifle that is capable of reliably using the 7.62×39 mm cartridge, without regard for the country of origin and the associated variations in manufacturing quality. Using the 7.62×39 mm cartridge ensures access to ammunition in nearly all parts of the world.

However, without some mitigation, use of the variations of the 7.62×39 mm cartridge can potentially result in lower than expected volume and pressure of gases produced (e.g., 20,000 psi less) which can result in unreliable cycling of the firearm, or higher than normal volume and pressure of gases in some cases (e.g., over 30,000 psi increase) which can be potentially destructive to the AR style rifle and hazardous or deadly to the operator.

BRIEF DESCRIPTION OF THE DRAWINGS

The detailed description is set forth with reference to the accompanying figures. The use of the same reference numbers in different figures indicates similar or identical items.

For this discussion, the devices and systems illustrated in the figures are shown as having a multiplicity of components. Various implementations of devices and/or systems, as described herein, may include fewer components and remain within the scope of the disclosure. Alternately, other implementations of devices and/or systems may include additional components, or various combinations of the described components, and remain within the scope of the disclosure. Shapes and/or dimensions shown in the illustrations of the figures are for example, and other shapes and or dimensions may be used and remain within the scope of the disclosure, unless specified otherwise.

FIG. 1 shows an example AR styled rifle, which is an environment wherein the disclosed embodiments may be practiced.

FIG. 2A shows a right-front perspective view of an example AR style upper receiver, with a bolt carrier therein, according to an embodiment.

FIG. 2B shows a right-front perspective view of an example AR style bolt carrier, according to an embodiment.

FIGS. 3A and 3B show right-front and left-rear perspective views, respectively, of an example AR style bolt carrier, with an AR style bolt, according to an embodiment.

FIGS. 4A-5D show various views of an example AR style bolt, with an AR style firing pin, according to various embodiments.

FIGS. 6A-7D show various views of an example AR style bolt, without a firing pin, according to various embodiments.

FIGS. 8A-8F show various views of an example AR style cam pin, according to an embodiment.

FIGS. 9A-9G show various views of an example AR firing pin, according to an embodiment.

FIGS. 10A-10G show various views of an example AR firing pin, according to another embodiment.

DETAILED DESCRIPTION

Overview

Representative implementations of devices and techniques provide novel AR style rifle upper receiver components, including a novel bolt, novel firing pins, and a novel cam pin. The novel upper receiver components are an exact fit for an AR style rifle (i.e., the novel components can be used with any AR style modular rifle that also has a novel upper receiver and novel bolt carrier, which can be seamlessly interchanged with the upper receiver and bolt carrier of any AR style rifle), and allow the reliable worldwide use of the 7.62×39 mm cartridge.

The novel upper receiver components are visually and tactilely differentiable from prior art AR style upper receiver components, making them identifiable. However, the novel upper receiver components are operated in the same manner as the standard AR style upper receiver components (to avoid the need for specialized training). The novel upper receiver components assemble and disassemble in the same way as standard AR style upper receiver components. However, the shape, features, and performance of the novel components (bolt 302, firing pin 304 (304a and 304b), and cam pin 306) distinguishes the novel components from standard or prior art components, and in some cases, prevents mixing novel upper receiver components with prior art upper receiver components, since they won't fit together.

Once the novel upper receiver components are installed together, the novel upper receiver 110 is a direct fit on a standard AR style rifle. The novel upper receiver components are designed for added strength and durability to withstand higher than normal volume and pressure of gases. Thus, they are capable of using a variety of 7.62×39 mm cartridges from around the world. The novel upper receiver components are also capable of functioning under water (or after being submerged) and are maintainable using normal AR armoring techniques.

FIG. 1 illustrates an example prior art AR style rifle, which is an environment wherein the disclosed techniques and devices may be employed. Various differences between the novel components disclosed herein and prior art components are discussed in this document, and the person having skill in the art may note additional differences not specifically discussed herein. A prior art AR style rifle becomes a novel AR style rifle 100 when the novel upper receiver 110 with the novel upper receiver components (302, 304, and 306) are installed therein.

Referring to FIGS. 1-10G, the following part number designations are used throughout:

Note that in some cases, the use of a part number in the discussion (including the drawings) may refer to the part without necessarily indicating whether the part is a novel part or a prior art part. The discussion will provide details regarding novel aspects of the novel parts indicated.

Referring to FIG. 1, rather than having a single-application receiver as found on some rifles, the AR styled rifles include a modularly designed receiver with separate upper 1 and lower 2 receivers. The lower receiver 2 includes a trigger guard and houses the trigger group 5. The lower receiver 2 also includes a means (e.g., screw-type fitting) for coupling the buttstock 3 and a pistol grip 4. The lower receiver 2 also includes a magazine well 6 for coupling and interchanging various cartridge magazines 7.

Referring also to FIG. 2A, an upper receiver 110 includes a coupler 25 for coupling the barrel 9, and the handguard 8. The upper receiver 110 is releasably coupled to the lower receiver 2 using front and rear pins. With the rear takedown pin removed, the upper receiver 110 can be pivoted at the front pin location 27, via the bushing 37, or it can be removed by removing the front pin. The upper receiver 110 also houses the bolt carrier 120 with the bolt 302 and the firing pin 304. An ejection port 24 is located at the upper receiver 110 for expelling spent casings.

Example Embodiments

Embodiments of modular rifles 100 are disclosed herein, as embodiments with various novel enhancements. Devices, systems, and techniques are also disclosed herein for enhancing modular rifles. Accordingly, the devices, systems, and techniques may be integral to a disclosed rifle 100, or they may be retrofit to a pre-existing rifle (individually or in various combinations).

For example, this document discloses novel upper receiver components, including a novel bolt 302, novel firing pin 304 (e.g., 304a and 304b), and a novel cam pin 306, which, when installed with a modular rifle, comprises a novel AR style rifle 100. The novel upper receiver components are visually and tactilely differentiable from prior art AR style upper receiver components, but all are operated without the need for specialized training. The novel upper receiver components are assembled to and disassembled from a rifle 100 in a similar way to a prior art AR style rifle. The novel bolt 302, novel firing pin 304, and novel cam pin 306 are assembled to a bolt carrier 120 and disassembled from a bolt carrier 120, which is assembled to and disassembled from an upper receiver 110 in a similar way to a prior art AR style rifle. However, the shape, size and operation of the novel upper receiver components are distinguishable from prior art AR components. The novel upper receiver components are designed for added strength, reliability, safety, and durability.

Referring to FIG. 2A, an example novel AR style upper receiver 110 is shown according to various embodiments, with a bolt carrier 120 disposed within. An example novel bolt carrier 120 is shown at FIG. 2B. The upper receiver 110 comprises a housing for upper receiver components for a standard or modified AR style rifle. The novel upper receiver 110 is configured to be a direct-fit replacement for a prior art upper receiver 1 on a standard or modified AR style (e.g., modular) rifle. The novel upper receiver 110 can be used with the novel bolt carrier 120, novel bolt 302, novel firing pin 304, and novel cam pin 306 disclosed herein, and in that configuration comprises a novel upper receiver assembly 102.

Referring also to FIGS. 3A and 3B, the novel bolt carrier 120 is constructed to hold the bolt 302 and firing pin 304 and related components. The bolt 302 is inserted into the front end of the bolt carrier 120 and is held there by the cam pin 306. In some examples, when the bolt 302 is locked in the ready firing position, there is a small gap between the bolt carrier 120 and the barrel extension. Instead of forcing the front of the novel bolt carrier 120 (e.g., the front of the novel bolt 302) against the breach of the barrel extension while in this position (as with prior art AR style bolt carriers 22), the small gap remains between the bolt carrier 120 and the barrel extension. The gap is useful to vent combustion gases that may travel around the face of the bolt 302, allowing the gases to vent through the upper receiver 110 rather than forcing the gases through the bolt 302, possibly damaging the bolt 302 or other components. The gap is also useful for reducing or eliminating bolt carrier 120 bounce and repetitive impact damage from the bolt carrier 120 repeatedly impacting the barrel extension.

A gas tube key (not shown in the drawings) is mounted to the surface of the bolt carrier 120, over a gas opening 202 in the bolt carrier 120. The gas tube key receives combustion gases from the barrel 9 via the gas tube 16 during a triggering event. Combustion gas entering the bolt carrier 120 from the gas tube key forces the bolt carrier 120 backwards within the upper receiver 110 to cycle the action of the rifle 100.

The upper receiver 110 is constructed to enclose and contain the bolt carrier 120, which is constructed to carry the bolt-related components (i.e., bolt 302, firing pin 304, and cam pin 306), and to allow their smooth and reliable movement within the upper receiver 110 during firing cycles. The bolt carrier 120 is arranged to move backward and forward (coaxially with the upper receiver 110 and the barrel 9 of the firearm) within the upper receiver 110 during the firing cycles. Repeated use (e.g., multiple cycles) of prior art components can cause wear to the prior art AR style components. Excessive combustion forces from sub-standard ammunition can further increase the wear and result in the premature destruction of a prior art upper receiver and associated components.

The novel bolt assembly 310 (i.e., bolt 302, firing pin 304, and cam pin 306) is shown installed in a novel bolt carrier 120 at FIGS. 3A and 3B. The components of the novel bolt assembly 310 (i.e., bolt 302, firing pin 304, and cam pin 306) include multiple features to strengthen the components, as well as to reduce wear during normal use and to prevent excessive or premature wear caused by excessive combustion forces. These features also promote the precise or optimized performance of the modular rifle 100.

A bolt carrier 120 is constructed to hold a bolt 302 and firing pin 304 and related components. The bolt carrier 120 carries the bolt 302 and firing pin 304 as the bolt carrier 120 moves during a firing cycle. The bolt 302 loads a cartridge and holds the cartridge stable for firing at one end of travel of the bolt carrier 120, with the firing pin 304 activating combustion. Then the bolt 302 clears the spent casing while moving to the other end of the travel of the bolt carrier 120 during the second half of a cycle.

A novel bolt 302 is shown with a novel firing pin 304 installed at FIGS. 4A-5D and is shown without a firing pin at FIGS. 6A-7D. The novel bolt 302 includes unique geometry and features for greater strength and reliability. However, the face 402 of the bolt 302 is designed to interface with a prior art chambered cartridge and the bolt lugs 33 are designed to lock in place at a standard AR barrel extension in the same way as a prior art bolt. The face 402 comprises the circular shaped flat area at the front of the bolt 302, inside the circumference 404, which is a circular perimeter of the face 402. The circumference 404 is inside the ring of bolt lugs 33 that protrude radially from the front area of the bolt 302. In other words, the circumference 404 is between the ring of lugs 33 and the face 402, and may also comprise a circular ledge surrounding the face 402.

Uniquely on the novel bolt 302, the ejector 34 is disposed at the face 402, but is moved to inside of the circumference 404 of the face 402 of the bolt 302, rather than intersecting with the circumference 404 of the face 402, as on prior art bolts. (See FIG. 5D, for example.) In some cases, the ejector 34 is disposed tangent to the circumference 404 of the face 402, still inside the circumference 404. The prior art positioning of the ejector 34 creates a potential weak area in the circumference 404 of the face 402 and the lugs 33, since a portion of the circumference 404 is notched out for the ejector 34. Positioning the ejector 34 inside of the circumference 404 results in a stronger circumference 404, including a stronger bolt face 402 and lugs 33, without a notch in the circumference 404.

Also, in some examples, the force of the extractor 42 is adjusted or improved by moving the pivot point of the extractor 42 toward the front of the bolt 302 (e.g., toward the face 402) to increase strength and to reduce wear. Moving the pivot point of the extractor 42 changes the fulcrum of the extractor 42, thereby adjusting the force of the extractor jaws on the rim of a cartridge. Accordingly, moving the pivot point toward the face 402 of the bolt 302 (10-30 thousandths of an inch, for example) results in a greater force by the jaw of the extractor 42 on the cartridge. Further, in some examples, the width of the extractor 42 may be increased (10-50 thousandths of an inch, for example) over the prior art for more surface contact with the cartridge rim at the jaw of the extractor 42.

Additionally, the novel bolt 302 includes a large flat-bottomed lower guide lug 44 that is not present on a prior art bolt. The guide lug 44 protrudes radially from the bolt face 402 similarly to the lugs 33, but spans at least two of the lugs 33 in width, and has a flat surface, level with a bottom surface of the bolt carrier 120, at the outer (bottom) edge configured to better engage with cartridges fed from the magazine 7. This lower guide lug 44 is much more robust than the smaller lugs 33 found on a prior art bolt, providing much greater strength and better tracking of the bolt 302 with the bolt carrier 120 during cycling.

The larger lower guide lug 44 is arranged to be at the bottom of the bolt 302 when deployed, so as to push the casing of a new cartridge from the magazine 7 and into the firing chamber. The novel lower guide lug 44 makes chambering a new cartridge more reliable, and less dependent on using the cartridge as a guiding mechanism during chambering, as is the case in the prior art.

For another example, the novel bolt 302 includes a tube-like support or stabilizer 63 at the rear of the bolt 302, with bearing surfaces 406 on the inside and outside surfaces of the tube-like (i.e., cylindrical) stabilizer 63. The stabilizer 63 is an added cylindrical extension component that extends beyond the length of a prior art AR style bolt. The rear bearing portion 70 of the firing pin 304 fits within the stabilizer 63, and the rear bearing portion 70 of the firing pin 304 is disposed within the stabilizer 63 during use. Further, the firing pin 304 is inserted into the bolt 304 through the stabilizer 63 when assembling the bolt carrier 120 components.

The bearing surface 406 on the inside surface of the stabilizer 63 helps to keep the firing pin 304 consistently aligned along the desired lengthwise axis during movement. The bearing portion 70 of the novel firing pin 304 has a snug bearing-like fit within the inner bearing surface 406 of the stabilizer 63, for on-axis movement without wobble. For example, the bearing portion 70 at the rear of the novel firing pin 304 fits closely with the inner bearing surface 406 of the stabilizer, for precise movement of the firing pin 304 within the bolt 302.

The outer bearing surface 406 of the stabilizer 63 also helps to support and to keep the novel bolt 302 consistent in movement and true along a desired lengthwise axis within the bolt carrier 120 (co-axial with the bolt carrier 120 and barrel 9). The outer bearing surface 406 of the stabilizer 63 has a snug bearing-to-bearing close fit within an inner cylindrical bearing surface 802 of the novel bolt carrier 120 that keeps the bolt 302 in line, including during movement within the bolt carrier 120. Accordingly, as a result of the stabilizer 63, walk and wobble (and thus bending and breaking or jamming) is reduced or eliminated for the firing pin 304 and the bolt 302 over the life of the components.

An opening 65 through the sidewall of the stabilizer 63 allows combustion gases to enter the stabilizer 63 and to push the firing pin 304 backward after ignition. This retracts the firing pin tip 66 from the cartridge casing at the face 402, and helps to prevent debris build-up on the firing pin tip 66 and potential tip 66 breakage. Less carbon build-up on the firing pin 304 results in better movement of the firing pin 304 during cycling.

As shown at FIGS. 5B and 5C for example, the opening 65 has an irregular shape (similar to the cam opening 48). The irregular shape of the stabilizer opening 65 gives room for the firing pin keeper 50 as the bolt 302 rotates during cycling (see FIG. 3B). The irregular shape of the stabilizer opening 65 also forms a cam with the firing pin keeper 50. The keeper 50 is inserted through a hole in the side of the bolt carrier 120 and is disposed transversely across the opening 65 to hold the bolt 302 in place within the bolt carrier 120, and to hold the firing pin 304 in place within the bolt 302, while allowing both the bolt 302 and the firing pin 304 some freedom of movement (including forward and back movement and rotational movement) during cycling. For example, as the bolt 302 moves forward or backward, the bolt 302 also rotates a few degrees as determined by the cam pin 306 moving in the cam pin opening 48 and the firing pin keeper 50 moving across the irregular opening 65.

Gas seal rings 61 are disposed mid-way along the length of the bolt 302 to isolate combustion gases to the rear portion of the bolt 302 (behind the gas seal rings 61). The forces created by the combustion gases during a cycle give movement to the firing pin 304, the bolt 302, and the bolt carrier 120. The gas seal rings 61 are arranged to keep the combustion gases contained at the rear portion of the bolt 302 so as to direct the gas forces for the desired action. The bolt 302 is forced outward (forward) relative to the bolt carrier 120 as the bolt carrier 120 is forced backward. The firing pin 304 is also forced backward.

A pair of raised circular gas seal bosses 408 protrude or project from the bolt 302 to keep the gas seal rings 61 in place on the bolt 302. The bosses 408 comprise ring-like ridges that rise from the cylindrical surface of the bolt 302 and are spaced apart so that the gas seal rings 61 can be disposed between the bosses 408. Often there are 3 gas seal rings 61 disposed between the bosses 408, however, fewer or more gas seal rings 61 may be used. In some cases, as shown at FIGS. 4B, 6B, 6C, 7A, and 7B for example, the bosses 408 may have different thicknesses. For instance, one boss 408 can be thicker (in width) than the other boss 408. An increased thickness on the rear-side boss 408, for example, can provide additional strength at that location and in that direction.

Referring to FIGS. 8A-8F, a novel cam pin 306 is shown in various views. The cam pin 306 is arranged to be inserted into the cam pin opening 48 in the bolt carrier 120 and through the bolt 302. The cam pin 306 has an opening 76 through the shaft 75 of the cam pin 306 arranged to align with the firing pin 304 when deployed. The firing pin 304 passes through the opening 76. In many embodiments, the novel cam pin 306 has a larger diameter shaft 75 than a prior art cam pin. The larger diameter shaft 75 is arranged to withstand greater forces for better operation with various combustion forces and provide a longer useful life. The firing pin alignment hole 76 can also have a larger diameter, to accommodate a larger diameter firing pin shaft 71 of a novel firing pin 304, as compared to the shaft of a prior art firing pin. To further distinguish the novel cam pin 306, the head 74 of the cam pin 306 can be 6-sided (or otherwise shaped), in contrast to the rectangular head of a prior art cam pin. The 6-sided head 74 of the novel cam pin 306 allows for easily distinguishing the novel cam pin 306 from a prior art cam pin.

Referring to FIGS. 9A-10G, a novel firing pin 304 (304a and 304b) is shown in various views and embodiments. In the various embodiments, the novel firing pin 304 includes unique geometry to ensure strength and more reliable ignition. The novel firing pin 304 (304a and 304b) includes an upper shaft 67, a lower shaft 71, and a tip 66, all or some of which can be made with a greater diameter than a prior art firing pin. If present, a greater diameter at any or all of these portions of the firing pin 304 can result in a stronger firing pin 304 that is resistant to bending and/or breaking.

In some examples, the novel firing pin 304 (304a and/or 304b) is arranged to protrude from the bolt face 402 through the firing pin opening 43 about 0.073″ (plus or minus ˜0.005″). This is further than a prior art firing pin extends, which typically extends from the bolt face 402 about 0.055″. The longer extension or protrusion from the face 402 of the bolt 302 improves the reliability of ignition. Further, the firing pin 304 can include a blunted tip 66 to prevent piercing the primer cup of the cartridge.

The novel firing pin 304 (304a and/or 304b) also includes an extended heel portion 69 with a large cylindrical bearing 70. The extended heel portion 69 combines the traditional prior art heel and stop components of a common firing pin into a single bearing component, with a smooth cylindrical outer surface. The bearing 70 of the heel portion 69 is advantageous for consistent movement of the firing pin 304 within the bolt 302. For example, the bearing 70 of the heel portion 69 moves within the stabilizer 63 to keep the firing pin 304 aligned within the bolt 302. The bearing 70 of the heel portion 69 is configured to closely mate and to move within the inner bearing surface 406 of the stabilizer 63. In other words, the bearing 70 closely fits within and interfaces with the inner bearing surface 406 of the stabilizer 63 in a bearing-to-bearing interface. Accordingly, nearly all of the firing pin 304 is enclosed by the bolt 302.

As shown at FIGS. 4A-5C, because of its length, the extended heel portion 69 with the bearing 70 extends most of the length of the stabilizer 63 of the bolt 302. In this position, the extended heel portion 69 is exposed within the opening 65 of the stabilizer 63. As mentioned above, the opening 65 is a “cut-out” portion of the stabilizer 63 that provides access for the firing pin keeper 50 to be disposed transversely across the firing pin 304 and across the opening 65 when installed in the bolt carrier 120.

Accordingly, the firing pin 304 also includes a recessed portion 92 disposed into the surface of the cylindrical bearing 70 as part of the heel portion 69. The recessed portion 92 is a “cut-out” area of the cylindrical bearing 70 of the heel portion 69. The recessed portion 92 comprises a recess in the cylindrical bearing 70 that also provides space or access for the firing pin keeper 50. The recessed portion 92 is arranged to align with the opening 65 through the side of the stabilizer 63 to accommodate a firing pin keeper 50. In some cases, the recessed portion 92 has a flat bottom surface, as shown in the figures. In other examples, the recessed portion 92 can have other-shaped profiles such as curves and the like.

When assembled, the firing pin keeper 50 is transversely disposed across the opening 65 in the stabilizer 63 and across the recessed portion 92 in the heel portion 69 of the firing pin 304. The bolt 302 rotates when pushed backwards by the combustion gases of a triggering event due to the cam pin 306, which is disposed through the bolt 302, riding in the cam-shaped opening 48 in the bolt carrier 120. The firing pin keeper 50 also cams the firing pin 304 backwards by pushing on the rear ledge of the recessed portion 92 of the firing pin 304, due to the keeper 50 riding on the cam shape of the opening 65 in the stabilizer 63. This also pulls the firing pin tip 66 out of the cartridge and back into the face 402 of the bolt 302.

Additionally, the heel portion 69 with the cylindrical bearing 70 includes a number of fine grooves 73 in the outer surface of the bearing 70. These grooves 73 run axially along the length of the bearing 70 and allow for reliable operation of the firing pin 304 while under water or after being submerged. In other words, the grooves 73 provide space for air and/or water to move, to prevent the firing pin 304 from being restricted by the snug fit of the bearing 70 in the stabilizer 63 when wet.

In a first example, a firing pin 304a is shown at FIGS. 9A-9G. The upper shaft 67, lower shaft 71, toe 72, and tip 66 of the firing pin 304a each have a generally cylindrical shape. Some of these portions of the firing pin 304a may have a larger diameter than a prior art firing pin, such as the upper shaft 67 and lower shaft 71, for example. Additionally, the tip 66 may have a more blunt shape than a prior art firing pin. As discussed above, the firing pin 304a includes the heel portion 69 with a bearing 70, a recess 92, and grooves 73.

In a second example, a firing pin 304b is shown at FIGS. 10A-10G. One or more of the upper shaft 67, lower shaft 71, toe 72, and tip 66 of the firing pin 304b have a generally semi-elliptical cross-sectional shape. In some examples, the upper shaft 67 has a cylindrical shape with a circular cross-sectional shape and the lower shaft 71 has a semi-cylindrical shape with a semi-circular (half-circle) cross-sectional shape. In some cases, the toe 72 has a tapering or triangular planar shape with a somewhat rectangular cross-sectional shape, with a thickness similar to or equal to the tip 66—which may also be generally planar and rectangular in cross-section. The novel firing pin 304b includes the unique cross-sectional shaft shapes (across the sections 67, 71, 72, and 66) for greater strength. In other examples, one or more of the sections 67, 71, 72, and 66 may have a different cross-sectional shape.

The tip 66 can have an oblong, rectangular, or polygonal cross-section, centered along a central axis of the firing pin 304b. The toe portion 72 tapers in width from a width of the lower portion 71 to a width of the tip 66. The multiple portions (67, 71, and 72) of the firing pin shaft strengthen the firing pin 304b against bending or breaking under extreme forces.

The tip 66 of the firing pin 304b can have a blunted striking surface. This unique geometry works to fold the metal of the primer cup of the cartridge, creating greater heat without piercing the metal of the cup, resulting in more reliable ignition. For example, the firing pin tip 66 is designed to fold the metal of the hardened primers common in Europe to generate heat and to help ignition as the metal is driven onto the primer's anvil. This allows the novel firing pin 304b to set off the hardened primers without having to increase the hammer force of the rifle by adding heavier springs.

The longer extension or protrusion of the tip 66 from the face 402 of the bolt 302 also improves the reliability of ignition, while the blunted tip 66 of the novel firing pin 304b prevents piercing the primer cup of the cartridge, which is more common with prior art firing pins.

The unique shaft shape of the firing pin 304b also allows the firing pin 304b to be correctly inserted into the bolt 302 and purposefully aligned to the firing pin opening 43 at the center of the face 402 of the bolt 302, based on the interior shape of the bolt 302. As shown at FIG. 5D for example, the firing pin opening 43 at the center of the face 402 can have an oblong shape (rather than a circular opening) to accommodate the oblong-shaped tip 66 of the novel firing pin 304b.

Although various implementations and examples are discussed herein, further implementations and examples may be possible by combining the features and elements of individual implementations and examples.

CONCLUSION

Although the implementations of the disclosure have been described in language specific to structural features and/or methodological acts, it is to be understood that the implementations are not necessarily limited to the specific features or acts described. Rather, the specific features and acts are disclosed as representative forms of implementing the claims.