The invention relates to a firearm comprising a housing (1), a magazine (2) for cartridges (3) which are preloaded in the direction of a transfer opening by means of a magazine feeder (7), a lock (8) which can be moved relative to the housing (1) in order to convey the cartridges (3), and a lock catch lever (4) which holds the lock (8) in a rear position when the magazine (2) is empty. A trigger element (9) is provided for automatically releasing the lock (8) into the front position when a loaded magazine (2) is inserted. An engagement surface (10) of the trigger element (9) protrudes into the movement path of a control surface (11) of the magazine (2) in a front starting position. The trigger element (9) is coupled to the lock (8) in a kinematic manner via an effective surface (12) at least during a part of the movement when moving from the front starting position into a rear end position. At the end of the coupled part of the movement, the lock (8) is offset towards the rear relative to the lock rear position by another portion along the lock movement path. The effective surface (12) of the trigger element (9) is disengaged again from the lock (8) in the rear end position of the trigger element (9).