Rapper B.G. ... aka Baby Gangsta ... aka one of the guys from Lil' Wayne's old group Hot Boys -- has been sentenced to 14 years in federal prison for gun possession and witness tampering.
The 31-year-old -- real name Christopher Dorsey -- appeared in federal court in New Orleans today ... after previously pleading guilty to being a felon in possession of a firearm during a 2009 traffic stop in eastern New Orleans.
According to Nola.com, officials say B.G. later obstructed justice by pushing one of his associates to falsely claim ownership of the firearm.
B.G. already had 3 felony drug convictions on his record.
No word on when the rapper will begin his sentence.