An improved selector device is provided for controlling the locking and striker mechanisms of a firearm. This device includes a movable button selector and a shaft rotatably mounted in said firearm in sliding engagement with the button selector. The shaft includes a base gudgeon which guides the selector in one direction as the selector slides over it. The shaft guides the button selector along a second direction and allows the selector to move in the second direction, which is substantially perpendicular to the first, by rotating as the button selector pushes the base gudgeon in the second direction.