Abstract: Disclosed are devices and methods for determining a fluid level of and the amount of fluid remaining in a container. A portable measuring device can include a housing, a sensor, and a measurement system. The sensor can be supported by the housing and can detect a fluid level of the container. The measurement system can be configured to receive information including a measurement of the container, to determine an amount of fluid in the container based on a measurement of the container and a detected fluid level of the container, and to output the amount of fluid in the container and geometric information of the container. A method can include supplying such a device, placing the device proximal to or in abutment with and moving the device along an outer surface of the container, providing a signal to a user, and outputting the amount of fluid in a container.

Abstract: A fire control group system for a firearm includes a trigger that includes a trigger base, a trigger extension extending from the trigger base, and an over-travel member coupled to the trigger base at a front end thereof. The trigger base has a sear hook extending therefrom and defining a recess and a transverse bore intersecting the recess. The over-travel member has a contact surface and is moveable relative to the trigger base such that a distance in a vertical direction between the contact surface and the trigger base is adjustable.

Abstract: A perforator quick disconnect system for an aerator device includes a perforator and a retaining device. The perforator has a head with an exterior configured to be received within a mounting block of the aerator device and a female component that extends into the exterior of the head. The retaining device has a connector configured to connect to the mounting block and a male component disposed within the connector and moveable relative thereto from a first position to a second position. The female and male components together form a quick disconnect mechanism such that when the perforator and retaining device are received by the mounting block, the male component engages the female component when the male component is in the first position to connect the retaining device to the mounting block and disengages the female component when in the second position to disconnect the perforator from the mounting block.

Abstract: A multipurpose tool that includes a handle and a body. The body has an opening that extends through the body and has a first set of pins that are removably connected to the body. The first set of pins are arranged along and adjacent to at least a portion of the perimeter of the opening and project away from the first side of the body. The multipurpose tool also includes a modular hammer and other tool features, some of which are configured to operate on a firearm for its disassembly and reassembly.

Abstract: An accessory mount system for connection to a rear sight block (RSB) of a Kalashnikov pattern firearm includes a locking insert that has a projection which extends in a first direction. The projection is adapted to be received within a first recess of the RSB for connection thereto. An adapter body is connected to the locking insert and has a projection that extends in a second direction opposite the first direction. The projection of the adapter body is adapted to be received within a second recess of the RSB for connection thereto. A mount body is connected to the adapter body and has an accessory interface which is adapted to connect to an accessory. An adapter body is secured with a push-pivot pin securely wedging the projection of the adapter against an internal wall of the RSB.

Abstract: A fire control group system for a firearm includes a trigger that includes a trigger base, a trigger extension extending from the trigger base, and an over-travel member coupled to the trigger base at a front end thereof. The trigger base has a sear hook extending therefrom and defining a recess and a transverse bore intersecting the recess. The over-travel member has a contact surface and is moveable relative to the trigger base such that a distance in a vertical direction between the contact surface and the trigger base is adjustable.

Abstract: A method of removing a trigger assembly from a firearm includes placing a projection of a pin removal tool against a first end of a trigger pin of a firearm. The projection of the pin removal tool extends from a first end of a handle of the pin removal tool. The projection is then pushed against the pin so as to cause the pin to partially unseat from its position within the firearm. The pin removal tool is then turned around and the head is engaged to the pin between the first end and a second end thereof via a notch of the head. The pin removal tool is pulled so that the trigger pin is removed from the firearm so as to release a trigger assembly which is at least partially held within the firearm by the trigger pin.

Abstract: A multipurpose tool that includes a handle and a body. The body has an opening that extends through the body and has a first set of pins that are removably connected to the body. The first set of pins are arranged along and adjacent to at least a portion of the perimeter of the opening and project away from the first side of the body. The multipurpose tool also includes a modular hammer and other tool features, some of which are configured to operate on a firearm for its disassembly and reassembly.

Abstract: A method of removing a trigger assembly from a firearm includes placing a projection of a pin removal tool against a first end of a trigger pin of a firearm. The projection of the pin removal tool extends from a first end of a handle of the pin removal tool. The projection is then pushed against the pin so as to cause the pin to partially unseat from its position within the firearm. The pin removal tool is then turned around and the head is engaged to the pin between the first end and a second end thereof via a notch of the head. The pin removal tool is pulled so that the trigger pin is removed from the firearm so as to release a trigger assembly which is at least partially held within the firearm by the trigger pin.

Abstract: A modular system for a firearm receiver which has a threaded annulus at a rear end thereof. The modular system includes a base that includes a front face, a rear face, and a thread helically extending along an exterior thereof between the front face and rear face and configured to engage with the threaded annulus of the receiver. The base includes a screw opening extending through the front and rear faces. The system also includes a screw and a first end cap. The first end cap has a body. The body has a front face and a threaded opening extending into the body and terminating therein. The screw has a threaded shank configured to extend through the screw opening of the base and into the threaded opening of the first end cap for connecting the base and first end cap.

Abstract: A delayed rotary blowback mechanism integrated into a firearm bolt and carrier subassembly. A plurality of lugs are configured at a rear of the bolt and seat within a mating profile of a barrel extension of the firearm in a fully chambered position. Chamfered locations are configured between the lugs and a receiving profile in the barrel extension for influencing linear to rotational motion of the bolt. A cam pin extends upwardly from the bolt and seats through a circumferentially directed slot configured within the bolt carrier. Upon initiating of the discharge cycle of a fired round traveling out the end of the barrel, the chamfered configuration results in the bolt and cam pin rotating within the carrier and the lugs subsequently separating from the barrel extension. The bolt and carrier retain sufficient inertia to cycle through the discharge cycle concurrent with reloading a subsequent cartridge.

Abstract: A delayed rotary blowback mechanism integrated into a firearm bolt and carrier subassembly. A plurality of radial locking lugs are configured at a rear end of the bolt and seat within a mating profile of a barrel extension of the firearm in a fully chambered position. A plurality of chamfered locations are configured between the lugs and a receiving profile in the barrel extension for influencing linear to rotational motion of the bolt. A cam pin extends upwardly from the bolt and seats through a circumferentially directed slot configured within the bolt carrier. Upon initiating of the discharge cycle, signaled by the round traveling through and out the end of the barrel, the chamfered configuration results in the bolt and cam pin rotating within the carrier and the lugs subsequently separating from the barrel extension, with the bolt and associated carrier retaining sufficient inertia to cycle through the discharge cycle to the set position concurrent with reloading a subsequent cartridge.

Abstract: A delayed rotary blowback mechanism integrated into a firearm bolt and carrier subassembly. A plurality of lugs are configured at a rear of the bolt and seat within a mating profile of a barrel extension of the firearm in a fully chambered position. Chamfered locations are configured between the lugs and a receiving profile in the barrel extension for influencing linear to rotational motion of the bolt. A cam pin extends upwardly from the bolt and seats through a circumferentially directed slot configured within the bolt carrier. Upon initiating of the discharge cycle of a fired round traveling out the end of the barrel, the chamfered configuration results in the bolt and cam pin rotating within the carrier and the lugs subsequently separating from the barrel extension. The bolt and carrier retain sufficient inertia to cycle through the discharge cycle concurrent with reloading a subsequent cartridge.

Abstract: A delayed rotary blowback mechanism integrated into a firearm bolt and carrier subassembly. A plurality of radial locking lugs are configured at a rear end of the bolt and seat within a mating profile of a barrel extension of the firearm in a fully chambered position. A plurality of chamfered locations are configured between the lugs and a receiving profile in the barrel extension for influencing linear to rotational motion of the bolt. A cam pin extends upwardly from the bolt and seats through a circumferentially directed slot configured within the bolt carrier. Upon initiating of the discharge cycle, signaled by the round traveling through and out the end of the barrel, the chamfered configuration results in the bolt and cam pin rotating within the carrier and the lugs subsequently separating from the barrel extension, with the bolt and associated carrier retaining sufficient inertia to cycle through the discharge cycle to the set position concurrent with reloading a subsequent cartridge.