A system, device, and method for measuring the temperature of a chambered projectile within a firearm are provided. A test ammunition round may include a projectile, a sleeve, and a case including a first end coupled to sleeve, and a second end coupled to the projectile. A thermocouple may be located within the projectile, and an electronic coupler may be coupled to the thermocouple, and extends through the case and the sleeve and exits the sleeve through a slot for coupling to a data acquisition system.

An improved weapon system modification directed to short stroke piston assemblies comprising: a housing having an inlet port for receiving gas from a barrel, a piston chamber and a piston contained within the chamber that, when actuated by gas, moves rearward toward a chamber contacting a bolt carrier and cycling the action; a front seating ring for receiving a front sleeve; a rear seating ring for receiving a rear sleeve; a barrel extending through the front sleeve, housing and rear sleeve defining one or more voids between the front sleeve, housing and rear sleeve and the barrel; filler material deposited and/or disposed in the void(s) that when cured or hardened, results in a barrel assembly dissipating heat and improving accuracy; a receiver plate included in the housing for attaching the housing to a receiver; a receiver block included in the housing for attaching the housing to the receiver; and, a lower track that can be attached to the housing and a barrel locking collar.

An improved weapon system modification directed to short stroke piston assemblies comprising: a housing having an inlet port for receiving gas from a barrel, a piston chamber and a piston contained within the chamber that, when actuated by gas, moves rearward toward a chamber contacting a bolt carrier and cycling the action; a front seating ring for receiving a front sleeve; a rear seating ring for receiving a rear sleeve; a barrel extending through the front sleeve, housing and rear sleeve defining one or more voids between the front sleeve, housing and rear sleeve and the barrel; filler material deposited and/or disposed in the void(s) that when cured or hardened, results in a barrel assembly dissipating heat and improving accuracy; a receiver plate included in the housing for attaching the housing to a receiver; a receiver block included in the housing for attaching the housing to the receiver; and, a lower track that can be attached to the housing and a barrel locking collar.

Representative implementations of devices and techniques provide a cooling system for an implement holster (such as a handgun holster, for example). In various embodiments, the cooling system provides fluid flow through at least a portion of the holster to cool the holster and the user. For example, the cooling system includes a cooling assembly adapted to move a fluid through a ducting layer of a multi-layer holster backer.

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.

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.

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.

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.

A bolt carrier having a first gas port, wherein the first gas port provides fluid communication between an interior and an exterior of the bolt carrier; a second gas port, wherein the second gas port provides fluid communication between an interior and an exterior of the bolt carrier; and a third gas port, wherein the third gas port provides fluid communication between an interior and an exterior of the bolt carrier.

A bolt carrier having a first gas port, wherein the first gas port provides fluid communication between an interior and an exterior of the bolt carrier; a second gas port, wherein the second gas port provides fluid communication between an interior and an exterior of the bolt carrier; and a third gas port, wherein the third gas port provides fluid communication between an interior and an exterior of the bolt carrier.