A press for forming large cylindrical bales includes a forward bale chamber for forming a bale core during the time a full sized bale located in a main bale chamber is being tied and discharged. A set of belts are mounted on a vertically shiftable roller so as to form a loop that delimits a rear portion of the forward chamber and a rear portion of the main chamber when the roller is in a lowered position and which is moved out of the way to permit a formed bale core to move from the forward chamber into the main chamber when the roller is in a raised position. In one embodiment a conveyor delimits the bottom of the forward chamber and cooperates with a first pickup to feed crop material to the forward chamber. A second pickup is arranged for delivering crop material directly into the main chamber. In a variant to the first embodiment a longer conveyor is used and the second pickup is omitted. The first pickup and longer conveyor cooperate to deliver crop material to the main chamber. In a second variant to the first embodiment, the conveyor and second pickup are omitted with a set of belts being arranged to delimit the bottom of the forward chamber and with the belt set loop and first conveyor being located for feeding crop material into the forward chamber when the shiftable roller is lowered and for feeding material to the main chamber when the roller is raised.