The gunfire in the 700 block of Selma Place was reported shortly after 4 p.m., according to San Diego police Officer Robert Heims.
The 61-year-old victim, whose name was not released, was taken to a hospital for treatment of a non-life-threatening gunshot wound to his left shin area, Heims said.
George Eisele, who had told police the shooting was an accident, was arrested at the scene and the rifle was recovered, according to Heims.