A surgical instrument handle having a cam-actuated system is disclosed. The surgical instrument handle includes a rotating member that defines a cam-actuating surface operatively engaged with a locking member, which is fixedly engaged to a reciprocating member for moving the reciprocating member between a retracted and extended positions. The cam-actuating surface of the rotating member is configured to permit the locking member to slide along the cam-actuating surface such that the tangential angle along the point of contact between the locking member and the cam-actuating surface is maintained at a predetermined angle.