Abstract: A trigger assembly group for use in firearms is disclosed. The trigger assembly group comprises a primary trigger connected to a secondary trigger that is arranged and configured to reduce the incidence of accidental discharge caused by inadvertently rearwardly actuating a primary trigger. The disclosed primary trigger and secondary trigger are arranged and configured for linear movement within a housing. The secondary trigger includes locking wing members that move from engagement with upper locking housing grooves to lower housing grooves. The disclosed trigger assembly group further includes a trigger shoe connected to the primary trigger, wherein the trigger shoe comprises a channel formed therein. A lower portion of the secondary trigger is configured to move from a forwardmost position, extending outwardly from the front face of the trigger shoe, to a rearmost position in which the lower portion of the secondary trigger recedes into the channel of the trigger shoe.

Abstract: A firearm lock mechanism includes a trigger, a hammer, a stirrup connected to the hammer at a stirrup connection point, and a spring operably connected to the stirrup at a spring connection point. Progressive pivoting of the trigger drives corresponding progressive pivoting of the hammer. The stirrup connection point is disposed forward of the hammer pivot point. One of the spring connection point, hammer pivot point, and stirrup connection point is offset relative to and laterally spaced between the others of the points to be a vertex of an intermediate angle cooperatively defined by the points. The angle increases in magnitude as the trigger drives pivoting of the hammer. A toggle line is defined between the trigger pivot point and the hammer pivot point. The trigger contacts the hammer at a contact point that shifts across the toggle line as the trigger drives pivoting of the hammer.

Abstract: A mechanism using flexure hinges as part of the trigger and/or safety mechanism of a firearm. Flexure hinges provide relative motion between two stiff members by the elastic deformation of an arbitrarily shaped flexible connector often implemented in metallic and composite materials. The flexure hinges are formed by flexure links connecting two stiff members. The flexure links connect various parts of the trigger assembly, such as a trigger component, including a shoe, plate, or safety, to a housing of the firearm. A method of creating the mechanism provides a trigger component, a housing, and connects the two parts by a flexure link with a flexure hinge.

Abstract: A selective fire firearm may be provided having a fully automatic open bolt and a semi-automatic closed bolt mode of operation. The firearm may include a trigger group having a trigger prop that ensures that, when the trigger is released in the fully automatic open bolt mode, the bolt carrier stops in an open bolt position held by an open bolt sear. The trigger prop may include a foot that, following a first trigger pull in the fully automatic open bolt mode, slides under and props a rear end of the trigger in a position that allows the open bolt sear to catch the bolt carrier when the trigger is released and propped but prevents the trigger sear from engaging the hammer.

Abstract: Trigger groups for striker-fired firearms have a frame defining a medial plane, a slide connected to the frame and operable to reciprocate between a forward battery position and a rearward recoil position, a barrel connected to the slide and having a forward muzzle end, a trigger assembly connected to the frame and movable between a forward trigger position and a rearward trigger position, a firing pin assembly connected to the slide and operable to reciprocate between a rearward retracted position and a forward extended position, the firing pin assembly including a forward-facing retention surface, the trigger assembly including a sear surface configured to selectively engage the retention surface to releasably restrain the firing pin assembly, a selector movable between a first selector position and a second selector position, and a connector operably engaged to the trigger assembly and to the selector.

Abstract: A trigger mechanism including a top sear for engaging a cocking piece, a transfer arm for engaging the top sear, and a safety lever and second stage sear which engages the transfer arm. The safety lever prevents unintentional firing of a firearm with the trigger mechanism. A bottom sear cooperates with the safety lever and the second stage sear. A reset spring biases the transfer arm. A single stage operation involves both a first stage spring and second stage spring upon trigger load application. In a two-stage operation, the first stage spring is engaged and then the second stage spring is also engaged. A selector pin provides flexibility to alter the mode of operation of the trigger mechanism between single stage trigger operation and a double stage trigger operation.

Abstract: Firearm control mechanisms have a frame, a trigger element connected to the frame and movable with respect to the frame, a selector connected to the frame and pivotable with respect to the frame about a pivot axis, the selector including a first cam surface operably engaged to a follower portion of the trigger element, the selector having a detent portion having a detent surface opposing a spring biased detent follower connected to the frame and operable to reciprocate against the detent surface, the detent surface having a plurality of stable positions, each corresponding to an operating condition of the fire control mechanism, and the detent portion being a body lacking any concave surfaces. The detent surface may have a plurality of flat cam surfaces. At least two of the flat cam surfaces may be perpendicular to each other. A corner may join the plurality of flat cam surfaces.

Abstract: The handgun contains a frame composed of polymer material, the frame contains a channel formed therein, wherein the channel contains sides, and a forward rail positioned within the channel.

Abstract: Provided are multi-mode firearms, triggers, kits, and methods of use that allow a user to select between a semi-automatic firing mode and a pull-and-release firing mode that fires the firearm upon both pulling the trigger and releasing the trigger, by using the selector switch or other mechanism to change the amount the trigger can move. A safe mode that prevents the firearm from firing may also be selected in various example embodiments by using the selector switch or other mechanism to change the amount the trigger can move. In certain example embodiments the trigger cannot move at all in safe mode, can move more in semi-automatic mode, and can move yet more in pull-and-release mode. The modes can be positioned for selection in any order. Kits comprising a trigger assembly and a selector assembly are provided for retrofitting conventional semi-automatic firearms.

Abstract: A rifle or portable firearm assembly (e.g., 310) configured to work with user-actuable sensors and systems (e.g., S1-S4), comprises a removable receiver assembly 312 attached to and responsive to a trigger assembly 50 which are removably received in a stock or chassis 316 having a middle section 324 with a trigger motion sensing sidewall segment with at least one trigger motion sensor (e.g., 340L, 340R) which does not physically contact or attach to the trigger assembly and is instead spaced from every component of the trigger assembly when the receiver is installed in said stock or chassis. The trigger motion sensor is configured to sense, from a selected standoff distance, without contacting or interfering the trigger assembly in any way, at least one of (a) the trigger's first stage movement or (b) actuation of a safety lever, and generate a “trigger motion sensed” signal in response thereto.

Abstract: A slidable trigger assembly for a firearm is described. The slidable trigger comprises a main body housing a trigger and a sear and a slider, slidably coupled with the main body. The slidable trigger assembly may include a slide adjuster configured to set the sear at a target position with respect to the slider. Alternatively, the slider moves laterally in response to physical manipulation of the slidable trigger assembly to set the sear at a target position with respect to the slider.

Abstract: A trigger mechanism or fire control for trigger operable devices includes a housing; a sear having a sear body coupled to the housing and including a primary engagement surface and an active sear support reset geometry; and a sear support coupled to the housing and having a body with a sear engagement surface and a passive sear support reset geometry. The primary engagement surface of the sear is moved into an overlapping condition with the sear engagement surface of the sear support as the sear is moved from a discharged position to a reset position after actuation of the trigger operable device. In addition, interaction between the active sear support reset geometry and the passive sear support reset geometry causes a mechanical displacement of the sear support to a reset position.

Abstract: Various examples of a detachable trigger guard for firearms are described. The trigger guard as a monolithic piece has components including a main body, a first connection portion at a first distal end of the main body, and a second connection portion at a second distal end of the main body opposite the first distal end thereof. At least one of the first connection portion and the second connection portion of the detachable trigger guard is elastically deformable to allow the detachable trigger guard to be removably coupled to a receiver portion of the firearm below a trigger of the firearm with the first connection portion coupled to either or both of a first pair of through holes on the receiver portion of the firearm and with the second connection portion coupled to either or both of a second pair of through holes on the receiver portion of the firearm.

Abstract: A surgical instrument includes a housing including a touch sensor having a sensor surface disposed thereon. The touch sensor is configured to sense an actuation pattern input on the sensor surface. A shaft extends distally from the housing and includes an end effector disposed at a distal end thereof. An actuation assembly is disposed within the housing and operably coupled to the end effector. A control module is operably coupled between the sensor surface and the actuation assembly. The control module is configured, in response to input of an actuation pattern on the sensor surface, to actuate the actuation assembly such that a function is performed at the end effector.

Abstract: A hammer extension design for use with various firearms, including specifically muzzle-loading firearms, that makes operating the hammer easier, faster, and safer. The present invention discloses a muzzle-loading firearm which includes a stock, a barrel fastened to said stock, a pivot mounted to said stock, a trigger and hammer mechanism comprising of a hammer and a lever arm both secured to said pivot.

Abstract: A trigger assembly is disclosed. The trigger assembly includes a trigger shoe having a top surface, a brace coupled to the trigger shoe, a joint coupled to the brace, a trigger bar coupled to the brace, a trigger hood coupled to the top surface of the trigger shoe and the joint, and a track disposed between the trigger hood and the trigger shoe, wherein the trigger shoe is configured to move along the track.

Abstract: Trigger module securing apparatus using internally threaded pins and threaded fasteners to secure a trigger module into the lower receiver of a rifle.

Abstract: Trigger groups for semi-automatic firearms have a frame, a hammer connected to the frame and movable between a cocked position and a striking position, the hammer being biased toward the striking position, a trigger element connected to the frame and movable by a user between a forward position and a rearward position, a selector connected to the frame and movable between at least a first position and a second position, and a plurality of retention facilities each operable to selectively restrain the hammer in the cocked position, and when the selector is in the second position to enable discharge of the firearm in response to movement of the trigger to the forward position after movement to the rearward position and to enable an additional discharge of the firearm upon release of the trigger to the forward position.

Abstract: Trigger groups for semi-automatic firearms have a hammer, a trigger element, a sear, a selector, and a disconnector assembly, the disconnector assembly operable when the selector is in a first position to retain the hammer in the cocked position in response to release of the trigger element to the rest position subsequent to discharge of the firearm by pulling the trigger element, and the disconnector assembly operable when the selector is in a second position to release the hammer to the striking position in response to release of the trigger element to the rest position subsequent to discharge of the firearm by pulling the trigger element, such that the firearm discharges once per cycle of the trigger element when the selector is in the first position, and fires once for each forward or rearward motion of the trigger element when the selector is in the second position.

Abstract: Trigger assembly for use in a weapon. Components of the trigger assembly include a spring, a hammer, a disconnector, a trigger and other components related to a trigger assembly.

Abstract: A device implementable on a firearm includes an adjustable multi-angle grip. The grip includes an upper portion and a lower portion. The upper portion is configured to be coupled to a receiver portion of the firearm. The lower portion is pivotably coupled to the upper portion via a hinge on a front side of the grip such that an angle between a longitudinal axis of the lower portion and a longitudinal axis of a barrel of the firearm is variable.

Abstract: A trigger assembly apparatus for a firearm which allows adjustment of the pre-travel distance a trigger travels before initiating a firing sequence and method of making the pre-travel adjustment using the apparatus disclosed herein. The apparatus generally comprises a trigger and a trigger bow, with the trigger bow having at least one threaded receptacle in a front lateral portion thereof. The pre-travel adjustment can be achieved by rotating a threaded fastener within the threaded receptacle and the method of adjusting the pre-travel can be accomplished without complete disassembly of the firearm.

Abstract: Adjustability of trigger pull force is enable by the use of a spring interfacing with a trigger shoe counterweight. The spring force is adjustable by use of a set screw interfacing with the spring. A pivot arm member acts between a trigger shoe counterweight and a firing pin release arm to fix the ratio of trigger shoe pull force and firing pin release arm force.

Abstract: Trigger groups for semi-automatic firearms have a frame, a hammer connected to the frame and movable between a cocked position and a striking position, the hammer being biased toward the striking position, a trigger element connected to the frame and movable by a user between a forward position and a rearward position, a selector connected to the frame and movable between at least a first position and a second position, a disconnector having a hammer engagement facility adapted to selectably engage the hammer, a disconnector control element movable between a first control position and a second control position, the disconnector being operably engaged to the disconnector control element, the disconnector operable to move in a first range of motion when the disconnector control element is in the first control position, and in a second range of motion when the disconnector control element is in the second control position.

Abstract: A trigger return spring assembly mountable on a frame of a firearm includes a trigger mounted on the frame pivoting about a first axis of rotation. A trigger bar attached to the trigger pivots relative to the trigger about a second axis of rotation fixed on the trigger. A bore extends through the trigger along a third axis oriented transversely to and positioned between the first and second axes of rotation. A plunger extends through the bore and is movable along the third axis. A first end of the plunger is attached to the trigger bar and a second end has a retaining surface oriented transversely to the third axis. A shoulder is positioned within the bore proximate to the trigger bar. A compression spring captured within the bore, between the shoulder and the retaining surface, exerts a force pushing the retaining surface away from the shoulder.

Abstract: A device for pulling the trigger of a firearm includes an actuator, a controller in signal communication with the actuator and a switch in communication with the controller. The actuator mounts on the firearm adjacent to the trigger. The actuator has a body movable into engagement with the trigger for pulling the trigger. The body is movable out of engagement with the trigger permitting the trigger to reset. The controller is adapted to transmit first and second commands to the actuator. The first command directs moving the body into engagement with the trigger, and the second command directs moving the body out of engagement with the trigger. The switch is adapted to transmit a first signal to the controller causing the controller to transmit the first command to the actuator, and a second signal to the controller for causing the controller to transmit the second command to the actuator.

Abstract: A trigger resistance mechanism, especially of rifles, comprising a trigger device, containing at least one class 1 lever (12) whose one arm is adapted to be controlled by the trigger (2) while a trigger (2) resistance spring (4) bears on the other arm. The spring (4) is fitted, at the end averted from the trigger (2), with a bearing element (3) that bears on a cam (1) that is seated in the firearm frame in a rotary way.

Abstract: A simulated magazine useful to provide for simulated firing of a firearm includes a cycling lever arm which is depressed once every time the firearm is cycled; a linearly shaped counting plunger; a plunger spring biasing the plunger in an upward position; and a spring assembly connected to the cycling lever arm and acting upon the plunger. Depression of the cycling lever arm causes the plunger to move incrementally upward. When the plunger is in a fully up state, a slide catch trigger extends upward from the magazine, the slide catch trigger causing a slide of the firearm to remain in a back, open state.

Abstract: A remotely activated trigger release for a firearm is disclosed. The disclosed trigger release can provide immediate disengagement from the firearm when a user ceases interaction with the trigger release. Trigger activation can he achieved by means of a handheld pneumatic pump that pressurizes an expandable member inside a hinged assembly which can provide a force to move the trigger.

Abstract: An apparatus and method for a slotted trigger actuation mechanism for a firearm are described herein. The slotted trigger actuation mechanism may be a slotted trigger bar interface. The slotted trigger bar interface may serve to increase a distance of trigger pull required to execute firing ammunition. A trigger body may comprise a trigger bias for increasing trigger work. The apparatus and method described herein may help to improve results during drop safety testing.

Abstract: A universal percussion trigger mechanism, comprising a trigger housing (22) with a magazine (1), safety catch (3), magazine latch (7), firing pin (8), trigger bar (23), spring (12) of the trigger bar, universal percussion mechanism (38), which is fixed in the receiver (20), and consists of a bracket for universal percussion mechanism (16), cocking piece (17) with a cocking indicator mounted on the axis of the cocking piece (18) and spiral mainsprings (19), sear (11) and a single-shot sear (27).

Abstract: A fire control group has a receiver having opposed sidewalls defining a space configured to receive a fire control group, the opposed sidewalls each defining a pivot pin aperture, the pivot pin apertures being registered with each other, a fire control group including a trigger received in the space, the fire control group defining a transverse pivot pin passage configured to be registered with the pivot pin apertures of the receiver, the fire control group including a pivoting operational element, the fire control group including a pivot pin supporting the pivoting operational element and received in the transverse pivot pin passage and the pivot pin apertures, the firearm having a hand grip aft of the trigger and defining a screw aperture, and a grip screw engaging the hand grip and engaging the fire control group. The grip screw may occupy a medial plane of the firearm.

Abstract: The present disclosure provides a trigger assembly and related method for a firearm (e.g., an AR, SR-25, or M4 style rifle, or another type of firearm). The trigger assembly minimizes inadvertent discharge of the firearm by blocking the trigger from rearward pivoting until pressure is applied to the center portion of the trigger. The system and method employ a configuration wherein a camming surface is engaged with a machined portion of the lower receiver once the trigger assembly is connected to the lower receiver via a pivot that extends through the trigger assembly and at least a portion of the lower receiver.

Abstract: A handgun sear has a sear body extending between a proximal end portion to a distal end portion. The sear defines a first engagement surface adjacent the proximal end portion and a second engagement surface positioned distally of the first engagement surface. The sear can pivot about the distal end portion between a cocked position and a displaced position. The second engagement surface can be used to arrest forward movement of the striker in the event of an impulse that causes the striker to disengage from the first engagement surface. The sear may be incorporated into a fire control assembly of a semiautomatic handgun or other firearm.

Abstract: A shotgun including a barrel, a receiver, a magazine well and a magazine can be provided. The barrel may include a breech end at which a chamber is provided. The receiver can include a forward end coupled to the breech end of the barrel and a first side having an ejection port. The receiver may have a bolt movable therealong, with the bolt including a stripping lug removably attached thereto. The magazine well that can be received along and mounted externally to the receiver may include an attachment portion for attaching the magazine well to the receiver, a magazine release latch, and a feed ramp. This feed ramp may include a body that is removably mounted to an existing tubular magazine of the shotg, in front of the magazine well.

Abstract: A sighting device includes a body, a lighting unit, a touch unit, and a controller, wherein the lighting unit, the touch unit, and the controller are disposed on the body, and the controller is electrically connected to the touch unit and the lighting unit. The body has an accommodating space for accommodating a lens or at least one lens assembly. A reticle or an optical beam splitter is disposed in the accommodating space, and a light generated by the lighting unit is projected onto a scale or hairline of the reticle or the optical beam splitter. The touch unit senses an external touch and generates a touch signal in correspondence to the external touch, and the controller adjusts the brightness level and/or the color of the light generated by the lighting unit based on the touch signal.

Abstract: A hybrid firearm receiver includes a receiver body having a first end, a second end opposite the first end, a substantially planar bottom surface extending from the first end to the second end and transitioning to two upwardly extending opposing sidewalls, and a top end, the receiver body extending along a longitudinal axis from the first end to the second end. The first end is integrally formed with the receiver body and includes a first outer face and a rail interface that facilitates receiving a clamping mount of a gunstock between side edges of the rail interface and the first outer face. The rail interface has a plurality of flats disposed along a first plane that is transverse and non-perpendicular to the axis. The top end, the two opposing sidewall, and the first end form trough extending transverse to the axis.

Abstract: Trigger groups for semi-automatic firearms have a frame, a hammer connected to the frame and movable between a cocked position and a striking position, the hammer being biased toward the striking position, a trigger element connected to the frame and movable by a user between a forward position and a rearward position, a selector connected to the frame and movable between at least a first position and a second position, a disconnector having a hammer engagement facility adapted to selectably engage the hammer, a disconnector control element movable between a first control position and a second control position, the disconnector being operably engaged to the disconnector control element, the disconnector operable to move in a first range of motion when the disconnector control element is in the first control position, and in a second range of motion when the disconnector control element is in the second control position.

Abstract: Trigger groups for semi-automatic firearms have a frame, a hammer connected to the frame and movable between a cocked position and a striking position, the hammer being biased toward the striking position, a trigger element connected to the frame and movable by a user between a forward position and a rearward position, a selector connected to the frame and movable between at least a first position and a second position, and a plurality of retention facilities each operable to selectively restrain the hammer in the cocked position, and when the selector is in the second position to enable discharge of the firearm in response to movement of the trigger to the forward position after movement to the rearward position and to enable an additional discharge of the firearm upon release of the trigger to the forward position.

Abstract: An ambidextrous charging handle for a semi-automatic rifle comprises left and right handles, a mechanism for securing the charging handle to the rifle when not in use, and at least one roller bearing positioned to facilitate smooth operation of the securing mechanism. Friction-reducing features may be provided to improve the sliding operation of the charging handle. Construction using aluminum or titanium permits the use of anodizing to improve surface toughness.

Abstract: Trigger groups for semi-automatic firearms have a hammer, a trigger element, a sear, a selector, and a disconnector assembly, the disconnector assembly operable when the selector is in a first position to retain the hammer in the cocked position in response to release of the trigger element to the rest position subsequent to discharge of the firearm by pulling the trigger element, and the disconnector assembly operable when the selector is in a second position to release the hammer to the striking position in response to release of the trigger element to the rest position subsequent to discharge of the firearm by pulling the trigger element, such that the firearm discharges once per cycle of the trigger element when the selector is in the first position, and fires once for each forward or rearward motion of the trigger element when the selector is in the second position.

Abstract: A trigger bar for a semi-automatic firearm. The trigger bar includes a longitudinal body with a rearward lateral arm. The arm includes surfaces for engaging the sear and the drop safety lifter of the firearm. The surfaces are configured to reduce trigger pre-travel distances by reducing a trigger travel distance prior to drop safety lifter engagement, sear engagement, and striker release. An over-travel stop reduces a trigger over-travel distance.

Abstract: A rear trunnion assembly includes: a modular rear trunnion fitting including a rear connection feature, an upper portion, and a lower portion; a folding hinge fitting including an upper lug, a lower lug, and a forward portion disposed under the modular rear trunnion fitting, the folding hinge fitting disposed on a rear side of the modular rear trunnion fitting, the forward portion including a first mounting hole configured to interface with the upper portion and a second mounting hole configured to interface with the lower portion; and a pivoting latch fitting configured to pivot with respect to the folding hinge fitting about an axis extending from the upper lug to the lower lug. The pivoting latch fitting may be configured to lock in at least one position with respect to the folding hinge fitting.

Abstract: A trigger mechanism includes a hammer element that has a ready position, an intermediate position, and a fired position. The hammer element includes a hammer sear and a notch positioned at a front of the hammer element. The trigger mechanism includes a trigger element has a ready position that retains the hammer element in the ready position. The trigger mechanism also includes a fired position that releases the hammer element. The trigger element includes a trigger sear that includes a hammer sear engagement zone and a notch engagement zone. When the hammer element is in the ready position, the trigger sear at least partially engages the hammer sear at the hammer sear engagement zone. When the hammer element is in the intermediate position, the trigger sear at least partially engages the notch at the notch engagement zone and not at the hammer sear engagement zone.

Abstract: Upgrading a customized configuration file can include replacing the configuration property value of the upgraded configuration file with the corresponding configuration property value of the customized configuration file in response to the configuration property value of the upgraded configuration file being the same as the corresponding configuration property value of the previous version configuration file and in response to the configuration property value of the upgraded configuration file being different than the corresponding configuration property value of the customized configuration file.

Abstract: The present disclosure provides a trigger assembly and related method for a firearm (e.g., an AR, SR-25, or M4 style rifle, or another type of firearm). The trigger assembly minimizes inadvertent discharge of the firearm by blocking the trigger from rearward pivoting until pressure is applied to the center portion of the trigger. The system and method employ a configuration wherein a camming surface is engaged with a machine portion of the lower receiver once the trigger assembly is connected to the lower receiver via pivot that extend through the trigger assembly and at least a portion of the lower receiver.

Abstract: A device and method for stabilizing a rifle scope that employs a pocket cut in the bottom of a scope base (picatinny rail) that precisely mates with a key formed on the top of a recoil lug, such that when the scope base is attached to the rifle's action receiver and mated with the lug's key, the lug holds the barrel and the scope base locked in tandem so that they move exactly together during recoil events or any vibrations experienced by the rifle.

Abstract: A trigger can include one or more kinesthetic features to provide increased mechanoreceptor stimulation. This can give a shooter increased kinesthetic awareness of the trigger pull. The trigger can include any number of different kinesthetic features in different configurations such as ridges, grooves, bumps or depressions, raised or depressed surfaces, bars, etc. These features can provide an increased sense of feel to encourage the straight, even, efficient and/or consistent pressing of the weapon's trigger to produce consistent and accurate shot placement. The trigger can include two kinesthetic features or reference points, such as parallel bars, on the trigger face. With the parallel reference points the operator can apply equal pressure across the face of the trigger during manipulation.

Abstract: An electromagnetically variable firing system for a firearm is disclosed which may include a trigger assembly or mechanism comprising an electromagnetically-operated control device which allows the user to select and adjust the trigger pull force-displacement profile electronically. In one embodiment, the control device may be an electromagnetic trigger mechanism comprising an electromagnetic snap actuator operated via a microcontroller. The microcontroller is configurable by a user to adjust the trigger force-displacement profile according to preset user preferences. The microcontroller energizes the actuator during a trigger pull according to a preprogrammed trigger force and/or displacement setpoint aided by a trigger sensor(s). The energized actuator creates a magnetic field which dynamically increases or decrease the trigger force required to fully actuate the trigger to discharge the firearm. In other embodiments, the control device may be an electromagnetic magnetorheological fluid actuator.

Abstract: In some embodiments, a firearm trigger assembly comprises a hammer arranged to pivot on a hammer axis. The hammer comprises a cavity offset from the hammer axis, and the cavity has an opening that extends along a length of the cavity. A secondary biasing mechanism comprises a support member and a biasing member. The support member comprises a first portion oriented in the cavity and a second portion arranged to support the biasing member. The first portion is fixedly attached to the second portion. The trigger assembly has a first orientation and a second orientation. The secondary biasing mechanism biases the hammer in a first direction about the hammer axis in the first orientation, and in a second direction about the hammer axis in the second orientation.