An Updated Assessment of the Federal Assault Weapons Ban: Impacts on Gun Markets and Gun Violence, 1994-2003

http://www.sas.upenn.edu/jerrylee/research/aw_final2004.pdf:
"Should it be renewed, the ban’s effects on gun violence are likely to be small at best and perhaps too small for reliable measurement. [Assault weapons] were rarely used in gun crimes even before the ban. [Large capacity magazines] are involved in a more substantial share of gun crimes, but it is not clear how often the outcomes of gun attacks depend on the ability of offenders to fire more than ten shots (the current magazine capacity limit) without reloading."