Do firearm purchase delay laws reduce aggregate homicide levels? Using variation from a 6-month countrywide gun demand shock in 2012/2013, we show that U.S. states with legislation preventing immediate handgun purchases experienced smaller increases in handgun sales. Our findings indicate that this is likely driven by comparatively lower purchases among impulsive consumers. We then demonstrate that states with purchase delays also witnessed comparatively 2% lower homicide rates during the same period. Further evidence shows that lower handgun sales coincided primarily with fewer impulsive assaults and points towards reduced acts of domestic violence.