Abstract: In various embodiments, an apparatus is provided, the apparatus comprising an assembly an assembly to operate in a recoil environment in which the assembly is mounted on a device that produces or transmits recoil; wherein at least one part of the assembly is self-lockingly fastened to a mating part, the mating part comprising another part of the assembly, a reciprocating part of a recoil-producing device, or another part of the recoil-producing device; the self-lockingly fastened parts including a threaded opening, and a non-threaded opening over the threaded opening, the non-threaded opening defining: a tapered opening to form a locking taper, or a tapered counter opening arranged to make taper-to-taper contact with a corresponding taper defined by a rotatably-driven part, wherein the threaded hole is arranged to mate with threading defined by the rotatably-driven part. Other embodiments may be disclosed and/or claimed.

Abstract: In various embodiments, an optic assembly mount arranged to receive an optic or a bracket on which the optic is installed, wherein optic assembly mount includes: a first undercut; and wherein an underside of the bracket includes a second undercut to mate with the first undercut; wherein the apparatus further comprises a rotatably driven fastener including a head to forwardly urge the bracket relative to the locating optic assembly mount to interlock the undercuts. Other embodiments may be disclosed and/or claimed.

Abstract: In various embodiments, an apparatus comprises a locating optic assembly mount arranged to receive an optic or a bracket on which the optic is installed, wherein the locating optic assembly mount includes: one or more locating fastener openings to receive one or more locating fasteners with threaded sections and non-threaded shoulders, wherein the non-threaded shoulders extend through the optic or bracket and below a surface located below the optic or bracket, each locating fastener opening including: a threaded hole to mate with the threaded section of the corresponding locating fastener; and a counter opening located above the threaded hole, wherein the counter opening is arranged to slip fit with the non-threaded shoulder of the corresponding locating fastener to align a center axis of the locating fastener with a center axis of the locating fastener openings. Other embodiments may be disclosed and/or claimed.

Abstract: A firearm or a firearm retrofit assembly to provide the firearm with gas compensation to reduce recoil, wherein a barrel of the firearm or firearm retrofit assembly includes a length having an egress for gas propelled from a chamber inside the barrel, the firearm or a firearm retrofit assembly includes a compensation device to mount in front or behind a front wall of a slide associated with the barrel, the compensation device including: a first side having an opening arranged to fit around a length of the barrel; and a second different side having an opening to expose the egress of the length of the bore.

Abstract: Some embodiments may include a firearm magazine base pad assembly or magazine extension assembly comprising a top, a bottom, and a cavity between the top and bottom, the cavity for a core or removable insert, the firearm magazine base pad assembly or magazine extension assembly further comprising: means for slidingly receiving a bottom of a magazine, the slidingly receiving means including a channel to receive a lip defined by the bottom of the magazine and tab slots to mate with tabs above the lip; and the core or removable insert located in the cavity. Other embodiments may be disclosed and/or claimed.

Abstract: An optic guard for a firearm may include: a frame; and a bracket having a first side to attach to a firearm assembly, the bracket integrally formed with the frame or fixably attached to the frame at a second side of the bracket. The frame may be arranged to protect a top and sides of the optic when the first side of the bracket is attached to the firearm assembly. In some embodiments, the second side of the bracket defines an optic attachment, wherein the frame protects the top and sides of the optic when the optic is coupled to the bracket using the optic attachment. In some embodiments, the first side of the bracket may define a protrusion or opening to mate with an opening or protrusion in front of an optic mounting platform.

Abstract: In some embodiments, a tunable recoil assembly is provided. The tunable recoil assembly may include a guide rod having a front end, a length, and a rear end; one or more springs around the length of the guide rod; and a removable cap releasably coupled to one of the ends of the guide rod. In some embodiments, the removable cap may be retained using a spring force, and may be slidingly coupled, twistingly coupled, or otherwise releasably coupled to the one of the ends of the guide rod.

Abstract: Methods and systems for low etch pit density 6 inch semi-insulating gallium arsenide wafers may include a semi-insulating gallium arsenide single crystal wafer having a diameter of 6 inches or greater without intentional dopants for reducing dislocation density, an etch pit density of less than 1000 cm?2, and a resistivity of 1×107 ?-cm or more. The wafer may have an optical absorption of less than 5 cm?1 less than 4 cm?1 or less than 3 cm?1 at 940 nm wavelength. The wafer may have a carrier mobility of 3000 cm2/V-sec or higher. The wafer may have a thickness of 500 ?m or greater. Electronic devices may be formed on a first surface of the wafer. The wafer may have a carrier concentration of 1.1×107 cm?3 or less.

Abstract: A firearm or firearm retrofit assembly may include a compensation assembly to receive gas expelled from a muzzle of a barrel or an egress in a length of the barrel. The compensation assembly may include one or more gas flow-directing sections to tune the flow of gas through the compensation assembly, which may reduce recoil. Other embodiments may be disclosed and/or claimed.

Abstract: Methods and wafers for low etch pit density, low slip line density, and low strain indium phosphide are disclosed and may include an indium phosphide single crystal wafer having a diameter of 4 inches or greater, having a measured etch pit density of less than 500 cm?2, and having fewer than 5 dislocations or slip lines as measured by x-ray diffraction imaging. The wafer may have a measured etch pit density of 200 cm?2 or less, or 100 cm?2 or less, or 10 cm?2 or less. The wafer may have a diameter of 6 inches or greater. An area of the wafer with a measured etch pit density of zero may at least 80% of the total area of the surface. An area of the wafer with a measured etch pit density of zero may be at least 90% of the total area of the surface.

Abstract: Some embodiments include an optic guard for a firearm, the optic guard including: a frame; and a bracket having a side to attach to a firearm assembly, the bracket integrally formed with the frame or fixably attached to the frame; wherein the frame is arranged to cover part of a front of an optic housing when the side of the bracket is attached to the firearm assembly. Other embodiments may be disclosed and/or claimed.

Abstract: An adapter assembly for mounting an optic on a firearm using nuts mountable on bolts, threaded studs, or threaded posts is provided. The adapter assembly may include a bracket having a bottom section to mount to a firearm assembly, and a top side to receive the optic; wherein the threaded posts are integrally formed on the top side of the bracket, or wherein the bracket includes: pockets arranged to mate with at least part of heads of the bolts or studs, the pockets on a bottom side of the bracket; and through openings to receive shanks of the bolts or a different part of the heads of the bolts, or shanks of the studs. Other embodiments may be disclosed and/or claimed.

Abstract: A barrel-mountable accessory to couple to a muzzle end of a firearm barrel, including: a first side having an opening arranged to fit around the muzzle end of the barrel; and a second different side having a taper pin opening; and a taper pin insertable into the taper pin opening of the barrel-mountable accessory, wherein the taper pin includes: a length including a first region arranged to mate with a taper interface provided on the muzzle end of the barrel; the length further including a second region to contact a sidewall that defines the taper pin opening of the second side; and means for driving the taper pin into the taper pin opening, wherein the driving means is located on an end of the taper pin.

Abstract: A gas block assembly may include a gas block including a gas port to receive gas provided by a gas port of a barrel; a tapered fastener opening; and a tapered fastener insertable in the tapered fastener opening, the tapered fastener including: a length further including a tapered section to contact a sidewall that defines the tapered fastener opening; and means for rotationally driving the tapered fastener into the tapered fastener opening. In other embodiments, an adjustable gas block includes sealing ring(s) on a groove in a rotationally actuated gas metering shaft.

Abstract: Some embodiments may include a barrel for a firearm, the barrel having a bore extending from a breech end of the barrel to a muzzle end of the barrel, the back of the bore comprising a chamber of the barrel, the barrel further comprising: barrel face on the breech end of the barrel; and a recess on the barrel face, the recess having a bottom that extends from the chamber of the barrel to an exterior side surface of the barrel. Other embodiments may be disclosed and/or claimed.

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.

Abstract: In some embodiments, an apparatus comprises an overmold charging handle having dimensions including a total length and a total width, wherein the overmold charging handle comprises: a shaft assembly including a first end to insert into a receiver of a firearm and a second end opposite the first end, the second end of the shaft assembly including a head, wherein a width of the head is less than the total width of the overmold charging handle; a latch to prevent movement of the shaft assembly away from the receiver when in a closed position; and a first material-cored handle fastened to the second end of the shaft assembly, the first material-cored handle comprising: an exterior of a second different material, the exterior exposing a section of a recessed core of the first material-cored handle. Other embodiments may be disclosed and/or claimed.

Abstract: A charging handle includes a shaft, a front end that is operably coupled to a firearm bolt carrier, and a head that is located on an opposite end of the shaft from the front end. One or more ventilation features may be located in a first half of the length of the shaft proximate to the front end of the charging handle to prohibit exhaust that travels from the front end along the upper surface and/or side surfaces of the shaft from reaching the rear of the firearm and/or the head of the charging handle.

Abstract: In some embodiments, an apparatus comprises an overmold charging handle having dimensions including a total length and a total width, wherein the overmold charging handle comprises: a shaft assembly including a first end to insert into a receiver of a firearm and a second end opposite the first end, the second end of the shaft assembly including a head, wherein a width of the head is less than the total width of the overmold charging handle; a latch to prevent movement of the shaft assembly away from the receiver when in a closed position; and a first material-cored handle fastened to the second end of the shaft assembly, the first material-cored handle comprising: an exterior of a second different material, the exterior exposing a section of a recessed core of the first material-cored handle. Other embodiments may be disclosed and/or claimed.