Gun Trafficking Prevention Act of 2017 This bill amends the federal criminal code to make trafficking in firearms a crime. Specifically, it prohibits: purchasing or transferring a firearm with the intent to deliver it to a prohibited person; providing false or misleading material information in connection with a firearm purchase or transfer; and directing, promoting, or facilitating such prohibited conduct. The prohibition does not apply to a firearm lawfully acquired to give as a gift or lawfully received as a gift. A person who commits a gun trafficking offense is subject to a prison term of up to 20 years (or 25 years if such person also acted as an organizer). A person who conspires to commit a gun trafficking offense is subject to a prison term of up to 10 years. The U.S. Sentencing Commission must review and, if appropriate, amend the sentencing guidelines and policy statements that apply to persons convicted of trafficking in firearms.