Studies to date provide little support for the view of many policymakers and much of the public that FSEs will necessarily reduce gun crime, either through deterrence of new offenses or incapacitation of dangerous offenders. For several reasons, however, the studies do not necessarily prove that FSEs are unsound policy. The research suggests that the effectiveness of FSEs depends, in part, on how the provisions are written, how they are communicated to the public, and how prosecutors and judges apply them. The Federal courts now have two overlapping and, in some respects, inconsistent sets of rules for firearm sentencing. The statutory and Sentencing Guidelines FSE provisions differ in important ways. Because the overlapping provisions make the law of sentencing for firearms complicated, this article provides a brief overview of the differences between the statutes and Federal Sentencing Guidelines as well as a discussion of the integration of the overlapping provisions. An examination of Federal FSEs focuses on evidence of underuse of FSEs and reasons why the FSEs are sometimes circumvented. A section on recent changes and their effects considers the effects of Court decisions in "Bailey" and "Muscarello" on the application of the FSEs, the provisions of P.L. 105-386, and empirical data on firearm sentences after the recent changes. Proposals are offered for developing fair and effective FSE's. 2 tables and 108 footnotes