To provide for mandatory prison terms for possessing, brandishing, or discharging a firearm or destructive device during a Federal crime that is a crime of violence or a drug trafficking crime.

Revises Federal criminal code provisions to set mandatory prison terms for possessing, brandishing, or discharging a firearm or destructive device during a Federal crime of violence or a drug trafficking crime. Establishes penalties for second or subsequent convictions. Bars the court from imposing probationary sentences or concurrent terms of imprisonment on persons convicted of such violations.