The FN 303 was involved in a controversial 2004 incident in Boston in which Victoria Snelgrove was accidentally shot in the eye and fatally wounded. Subsequent tests by Boston Police indicated that the 303's accuracy "decreased significantly" after about three hundred firings. This is circumstantially corroborated by testimony of the officer who fired the weapon, stating that he was aiming at a rioter throwing bottles and did not even know that a bystander had been hit.
A fifteen million dollar wrongful death lawsuit against the City of Boston and FN Herstal was settled in July 2006. In 2007 the Boston Police destroyed their remaining FN303s, stating they were more powerful and lethal than had been anticipated.
During violent protests in front of the ARCELOR [former ARBED] building in Luxembourg city on May 11, 2009, the weapon was used for the first time by Luxembourgish police forces. An RTL cameraman was shot at the hand, breaking one finger.