This Buck Privates knockoff concerns the misadventures of the three Patterson brothers: Charley (Wayne Morris), Eddie (Tom Brown) and Kenneth (William T. Orr). Pampered by their pacifistic mother Margaret (Irene Rich), the Patterson boys do everything they can to avoid being drafted into the Army. Once they've donned unifom, however, our heroes calmly and courageously do their patriotic duty, while their mother at last realizes it's all for the best. Before this happens, however, the audience is subjected to all manner of goofy slapstick setpieces, including a trained-seal bit right out of the Mack Sennett era. Incidentally, Three Sons O' Guns costar William T. Orr was the son-in-law of Jack L. Warner, whose studio produced the film.