Quawi Twiggs must serve 85 percent of the prison term imposed Friday before becoming eligible for parole.
Camden County prosecutors say Twiggs was 17 when he shot 50-year-old Kevin Archie in May 2010, at the older man's home in Camden. Archie died from his wounds several days later.
The case eventually was moved to adult court, and the now 19-year-old Twiggs pleaded guilty in May to aggravated manslaughter.
Twiggs' attorney said he planned to appeal the sentence, saying the judge didn't adequately weigh allegations that Archie had physically abused his son.