Abstract: Mid-size balers and methods for compressing material into bales are disclosed. An exemplary baler (10) comprises a cylindrical baling chamber (24) configured to receive the material. The baling chamber is formed by a pair of circular, disk-shaped end plates (26) limiting opposite end faces of the baling chamber. The baling chamber is further formed by an axial motion actuator operatively associated with at least one of the end plates. The axial motion actuator including at least one piston providing an axial force to position the at least one of the end plates and react to forces of the bales (215) against the at least one of the end plates during operation. The baling chamber is further formed by a driven endless belt (12) guided by a plurality of rollers (20, 30, 32, 34, 42). The endless belt extends around the outer, circular perimeter of the end plates, forming a cylindrical periphery of the baling chamber.