An apparatus for ambidextrous control of a bolt carrier and/or a magazine release is disclosed. In certain examples, the apparatus includes a lower receiver of a firearm including a protrusion extending outward from a first side of the lower receiver, the protrusion. The protrusion, in certain examples, includes a first slot for receiving an L-shaped lever, the L-shaped lever having a vertical arm coupled to a bolt catch lever and a horizontal arm that extends through a trigger area to a second side of the lower receiver that is opposite the first side. In certain examples, the protrusion also includes a second slot for receiving a magazine catch lever.