Although the number of craft-produced small arms and light weapons is difficult to estimate, they are prevalent and range broadly in sophistication and quality.

Improvised and craft-produced firearms remain an important source of firepower for a wide range of actors, including tribal groups, poachers, criminals, insurgent groups, and even some states and quasi-state groups. In various locations, these weapons account for most of the firearms used in crime; in others, their production is institutionalized, providing essential income for local gunsmiths.

Based on extensive research in four Nigerian states, the Briefing Paper Handmade and Deadly: Craft Production of Small Arms in Nigeria finds that the use of craft-produced weapons in firearm-related crime in those states ranges from 32 per cent (Adamawa state) to 69 per cent (Plateau state).

Criminals purchase weapons unable to fire live ammunition legally and at low costs across Europe, converting them into lethal firearms with little to no training or expertise. The Small Arms Survey report From Legal to Lethal: Converted Firearms in Europe provides a detailed examination on the topic.