A baler comprises a baling chamber (C) that includes a bale-forming channel (A) having an inlet end (13) and an outlet end (14), a plunger (D) mounted within the channel for compressing bale material (1) in the channel and driving the compressed bale material towards the outlet end of the channel and a rotary drive mechanism (X) for driving reciprocating movement of the plunger. The baler also includes an additional drive means (22, D2) for driving the compressed bale material (1) towards the outlet end of the channel, thereby reducing torque in the rotary drive mechanism (X).
