A firearm synchronized discharge device for facilitating a synchronized discharge of two or more firearms are described together with associated systems, firearms and methods. The device includes an actuator for engaging with a movable trigger of a first firearm, a sensor configured to generate a signal indicative of a force applied to the trigger and a first controller operatively coupled to the sensor and to the actuator. The actuator is configurable between a first configuration that prevents movement of the trigger toward a firearm-discharge position of the trigger, and a second configuration that permits movement of the trigger toward the firearm-discharge position of the trigger. When the force meets a criterion and the one or more other firearms are ready for discharge, the actuator is caused to transition from the first configuration to the second configuration to permit actuation of the trigger and discharge of the firearm.

A pistol-to-rifle conversion kit (100) includes a rifle body (26) that includes a lower receiver (28), which includes a grip mounting portion (30), which is rearwardly adjacent to a trigger guard (32), which is rearwardly adjacent to a magazine well receiving portion (34). An auxiliary trigger (46) is sliding mounted in the rifle body (26) and includes an elongate member (48) and a forward trigger interface member (50), which extends from a forward portion of the elongate member (48) and which is configured to interface with a trigger (13) of a pistol (14) mounted in the rifle body (26), and a trigger member (56) which extends from the elongate member (48) for directly contacting a shooter's finger.

A pistol-to-rifle conversion kit (100) includes a rifle body (26) that includes a lower receiver (28), which includes a grip mounting portion (30), which is rearwardly adjacent to a trigger guard (32), which is rearwardly adjacent to a magazine well receiving portion (34). An auxiliary trigger (46) is sliding mounted in the rifle body (26) and includes an elongate member (48) and a forward trigger interface member (50), which extends from a forward portion of the elongate member (48) and which is configured to interface with a trigger (13) of a pistol (14) mounted in the rifle body (26), and a trigger member (56) which extends from the elongate member (48) for directly contacting a shooter's finger.

A hammer usable with a firearm having a bolt carrier that is configured to travel forward and rearward within the firearm during a firing operation of the firearm. The hammer includes a mounting portion configured to rotatably constrain the hammer within the firearm and a firing pin contact portion configured to rotate upward to a vertical most position and contact a firing pin. The hammer further includes a sear notch configured to contact a trigger, and an extended surface that is configured to contact a bottom portion of the bolt carrier when the bolt carrier travels in a rearward direction after firing of the firearm. The extended surface allows for additional travel of a bolt carrier group of the firearm.

A hammer usable with a firearm having a bolt carrier that is configured to travel forward and rearward within the firearm during a firing operation of the firearm. The hammer includes a mounting portion configured to rotatably constrain the hammer within the firearm and a firing pin contact portion configured to rotate upward to a vertical most position and contact a firing pin. The hammer further includes a sear notch configured to contact a trigger, and an extended surface that is configured to contact a bottom portion of the bolt carrier when the bolt carrier travels in a rearward direction after firing of the firearm. The extended surface allows for additional travel of a bolt carrier group of the firearm.

A pistol conversion kit may be constructed and arranged for converting a pistol to a bull-pup format rifle by attaching an elongated barrel to the pistol. The pistol conversion kit may include a two-part chassis defining a compartment into which the pistol and elongated barrel may be seated behind a handle and trigger guard integrated within the chassis such that the pistol is located behind the pistol conversion kit trigger thereby positioning the pistol in a bull-pup configuration within the chassis. The pistol conversion kit may include a number of sub-assemblies for operating the pistol seated within the chassis and may further include a barrel safety system arranged for preventing use of the pistol conversion kit trigger unless a properly sized elongation barrel is attached to the pistol.

A pistol-to-rifle conversion kit includes a rifle body that includes a lower receiver, which includes a grip mounting portion, which is rearwardly adjacent to a trigger guard, which is rearwardly adjacent to a magazine well receiving portion. An auxiliary trigger is sliding mounted in the rifle body and includes an elongate member and a forward trigger interface member, which extends from a forward portion of the elongate member and which is configured to interface with a trigger of a pistol mounted in the rifle body, and a trigger member which extends from the elongate member for directly contacting a shooter's finger.

A pistol-to-rifle conversion kit includes a rifle body that includes a lower receiver, which includes a grip mounting portion, which is rearwardly adjacent to a trigger guard, which is rearwardly adjacent to a magazine well receiving portion. An auxiliary trigger is sliding mounted in the rifle body and includes an elongate member and a forward trigger interface member, which extends from a forward portion of the elongate member and which is configured to interface with a trigger of a pistol mounted in the rifle body, and a trigger member which extends from the elongate member for directly contacting a shooter's finger.

A method for disassembling and converting a traditional AR-15 firearm into a bullpup configuration of an AR-15 firearm assembly includes releasing and removing at least a firearm but stock and a standard bolt carrier group from the AR-15 and then replacing the removed components with elements from a bullpup kit, namely a bullpup bolt carrier group that includes a bolt carrier and a spring assembly, the spring assembly having a plurality of radial spaced apart compression springs that are loaded when the bolt carrier recoils.

A controlling device and methodology for firearms interfacing the trigger mechanism, trigger finger, and the innermost and/or upper-innermost region of the firing hand as a means to adaptively govern incremental trigger movement and variable trigger pull force in order to accurately discharge a singular round of ammunition and, in alternative method, adaptively regulate and govern a variable cyclic firing ratio and sequential discharge rate. In use, coinciding contraction of the firing hand and trigger finger bring the controller device in concert with the trigger and innermost region of the firing hand thereby effectively isolating the controller with uniformly balanced isometric tension. Trigger movement and trigger pull force being regulated incrementally by utilization of variable isometric tension applied to the controller between the trigger finger, trigger, and the innermost region of the firing hand.