Sometimes referred to elsewhere as a "psychopathic killer," "Baby Face" Nelson's exploits ended in a bloody shootout at Barrington, Illinois in 1934. The most his wife and criminal companion, John Paul Chase, could do for him after the escape with his body from the shootout scene was place Nelson in a roadside ditch. Special agent Herman Hollis carried a shotgun and service revolver; Inspector Samuel Cowley carried a Thompson .45 caliber with a drum magazine holding 50 rounds, in addition to his service revolver. As most know, both Hollis and Cowley also met their death at Barrington.
When Nelson's body was found later in a ditch, he was dead and so were Cowley and Hollis. The autopsy report in the Dillinger file reveals Nelson actually died from (1) .45 round entering his side and clipping major arteries/organs. Obviously the .45 round came from Cowley's Thompson. Hollis died of a head wound to the rear; Cowley died of stomach wounds. Although there were bullet proof vests at the Chicago FBI Office, the shooting investigation later determined neither Hollis nor Cowley put one on before they left the office to join in the chase. A vest would not have saved Hollis regardless.
But how many rounds actually hit Nelson? If you guessed "17" you're right. A phone conversation with FBI Headquarters at the time recorded this info.