Back in the 60's, my father took an AK round that collapsed a lung while he was with the 173rd Abn. Bde. (Sep). After the hospitalization, he was made a cadre member at Ft. Wolters, TX-- but not allowed back on jump status.
He then managed to get into Ranger School and finish it. He is still rated as 30% disabled.
He later commanded a LRRP detachment on his second tour.