Improvements in technology and information sharing have transformed PMFs from crude, impractical homemade devices of limited value to most criminals into highly functional weapons that are increasingly viewed as viable substitutes for factory-built firearms. The effectiveness of national and international small arms control regimes are gradually being eroded; the lack of serial numbers on such weapons, for example, undermines tracing efforts that have been a cornerstone of investigations. 

The trafficking of firearms and their use in criminal violence in Europe has received significant attention from researchers and policymakers. Less is known, however, about the illicit proliferation of firearm ammunition and other explosive munitions. Currently, detailed data on illicit munitions in Europe can only be accessed through specialized law enforcement agencies. National seizure statistics often lack the necessary detail for policy-relevant analysis, as do the media reports, which often include incomplete or inaccurate information on the types and calibres of ammunition.