The incident happened on Broad Street in Keyport.
The child's injuries are not life threatening, and the shooting is said to be accidental.
Police say he was playing with the gun when it accidentally went off, striking him in the leg.
He was admitted to Jersey Shore Medical Center, where he needed stitches. He will not need surgery and did not break any bones.
Sources say the gun belonged to his father, and it appears to be legally owned.
The shooting remains under investigation by Keyport Police and the Monmouth County Prosecutor's Office.
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