The vertical chamber of the open throat, vertical chamber baler has its bottom inlet opening devoid of a starter roll. A resilient rotary rake tine assembly positioned below and ahead of the inlet opening picks up crop material from the ground and delivers it to a rigid tooth feeder spaced below the inlet opening in vertical alignment therewith. At the beginning of each bale forming cycle when the chamber is small and empty, the rigid tooth feeder propels the crop material into the chamber and against the upwardly moving rear belt stretch which encourages the material to tumble forwardly against the downwardly moving front belt stretch. The oppositely moving surfaces presented by the front and rear belt stretches encourage the tumbling material to coil into a bale core, which ultimately forms a larger bale. In the event loose material drops through the bottom inlet opening during core starting, such material is immediately returned to the chamber by the rigid tooth feeder along with other material delivered to the rigid tooth feeder in the meantime.