This chapter contributes to the emerging literature that examines the threat level 3D printed firearms pose to international security. It has shown the current risk from 3D-printed firearms is low. It determines the threat and implications of 3D printed firearms for international security and public safety. At present, given 3D printers are still an emerging technology and there is little evidence about the capacity in which they are being used for firearm manufacture and proliferation, this is a speculative space, and the level of threat 3D printed firearms pose can only be theorized. By examining the current capabilities of 3D printed firearms and challenges to using them and the related threat they pose, this chapter has argued the risk of an extreme event occurring in the near future as a result of a 3D printed firearm is low.