An apparatus for installing a high-pressure gas cartridge of this invention comprises: a high-pressure gas cartridge attachment and detachment apparatus for an air gun comprising: a high-pressure gas cartridge housing provided in a clip of an air gun; a back grip panel for a grip formed as a clamp lever; a lever rotation axis constituting a rotation fulcrum for a back grip panel; and a pressing curved surface capable of pressing a bottom part of the high-pressure gas cartridge, wherein a side grip panel of the grip is provided in an attachable and detachable manner so as to open and close the high-pressure gas cartridge housing, the high-pressure gas cartridge may be attached and detached with the back grip panel of the grip rotated about the lever rotation fulcrum so as to be in an open state, and the back grip panel presses against the bottom of the high-pressure gas cartridge due to rotation centered about the lever rotation axis so as to be closed and so as to push up and install the high-pressure gas cartridge A.

An assembly for use on weapons includes an illuminated gun sight system to permit the user to aim and shoot the weapon in varying ambient light conditions and including a first light emitting element on a front sight and a second pair of light emitting elements on a rear sight of the firearm, a light generating source to provide light to the first light emitting element and the second pair of light emitting elements; the first and second light emitting elements including a light modifying element to produce a distinct luminous reference shape of uniform light intensity throughout a visible light radiating area. A servo system sensor is responsive to ambient light conditions for adjusting the intensity of light radiating from the light emitting elements so that the intensity of light radiating from the light emitting elements increases and decreases in direct relation to changes in ambient light conditions. A low ammunition warning system includes a detector and a circuit for tracking depletion of ammunition contained in the weapon. Visible and tactile signals, responsive to the circuit, warn the user when a known pre-set low ammunition count has been reached.

A display device for showing the exact number of rounds remaining in a firearm magazine without removing the magazine from the weapon. The device comprises a grip panel assembly attachable to the frame of an automatic pistol. The assembly includes a grip having a transparent window through which a numbered scale can be seen. The frame and magazine of the firearm are modified, if necessary, to include elongate slits through which a portion of the follower is visible. As the weapon is fired a highly visible marker, strategically placed on the exposed follower, points to succeeding numbers on the calibrated scale, indicating the number of rounds in the magazine at any given time while the magazine remains in the firearm. This method of counting rounds is adaptable to automatic rifles having exposed magazines.

A firearm magazine with loading status indicator. the magazine comprising a housing (1) for storing bullets in a stacked configuration, with an opening (6) for receiving the bullets (5); a follower (3) for supporting the bullets within the housing, movable along the housing and resiliently pressing towards the opening, so that at any time, when there exist at least one bullet within the housing it is presented at the opening, ready to be discharged; an indicator having a prominence (7), which in one indication state the prominence protrudes outside the housing and in another indication state the prominence does not protrude outside the housing, wherein one of the indication states corresponds to a state where the magazine is in a full condition, that is when it is filled with bullets up to a maximal capacity, and another indication state corresponding to a state where at least one bullet is missing with respect to full condition.

An automatic cartridge monitoring and indicator system for a firearm includes: a magazine for storing a plurality of cartridges; a follower mechanism in the magazine for feeding the cartridges from the magazine into the firearm; an actuator movable with the follower mechanism; a monitoring device disposed along the path of the follower mechanism and operable by the actuator to monitor the level of the follower mechanism and the level of cartridges in the magazine; and an indicator device responsive to the monitoring device for providing a representation of the level of cartridges in the magazine.