Notorious hit man Salvatore “Sammy Bull” Gravano, whose testimony helped sink mob boss John Gotti, failed Thursday in a bid to shorten his federal drug sentence.

Citing his “longstanding reputation for extreme violence,” Brooklyn Judge Allyne Ross declined to shave three years off Gravano’s term for running an ecstasy ring in Arizona.

Ross sentenced Gravano to 20 years in prison in 2002 and said at the time that he likely deserved more because of his bloody Mafia résumé.