An assembly for a bolt catch on a firearm having a bolt that slides between a latched position and an unlatched position, the bolt held in the latched position by a bolt catch mechanism that includes a catch-release actuator pivotally mounted on the rifle to provide for latching and unlatching of the bolt by a user, the assembly including a lever having an L-shaped body that comprises a first leg and a second leg that is formed at substantially a right angle to the first leg, the first leg having a free end on which is formed a mounting member; and a clamp member structured to attach to the mounting member on the lever to enable clamping of the lever to the catch-release actuator in a manner that does not require disassembly of the firearm or disassembly or removal of the catch-release actuator from the firearm.