Our knowledge about neuronal activity in the sensorimotor cortex relies primarily on stereotyped movements which are strictly controlled via the experimental settings. It remains unclear how results can be carried over to less constrained behavior, i.e. freely moving subjects. Towards this goal, we developed a self-paced behavioral paradigm which encouraged rats to conduct different types of movements. Via bilateral electrophysiological recordings across the entire sensorimotor cortex and simultaneous paw tracking, we identified behavioral coupling of neurons with lateralization and an anterior-posterior gradient from premotor to primary sensory cortex. The structure of population activity patterns was conserved across animals, in spite of severe undersampling of the total number of neurons and variations of electrode positions across individuals. Via alignments of low-dimensional neural manifolds, we demonstrate cross-subject and cross-session generalization in a decoding task arguing for a conserved neuronal code.