[20180822]IN10957_枪械控制：3D打印AR-15下接收机.pdf

CRS INSIGHT Prepared for Members and Committees of Congress INSIGHTINSIGHTi i Gun Control: 3D-Printed AR-15 Lower Receivers -name redacted- Specialist in Domestic Security and Crime Policy August 22, 2018 The possibility that criminals could use three dimensional-printing (3D-printing) technology to produce “untraceable” firearms, including AR-15s, is an issue of growing concern for some lawmakers. It overlaps in part with the issue of 3D-printed “undetectable” firearms discussed in a previous Insight (CRS Insight IN10953, Gun Control: 3D-Printed Firearms). Defense Distributed, a federally licensed firearms manufacturer, recently uploaded 3D-printable computer assisted design (CAD) files on its website for an AR-15 type rifle, including its lower receiver. The lower receiver is the “controlled part” of an AR-15 under federal law and, thus, the main component around which a fully functional firearm can be assembled. Defense Distributed demonstrated that a 3D printer could be used to produce an AR-15 lower receiver out of a polymer material, but functional reliability appeared to remain an issue. On July 31, 2018, a federal judge granted a temporary injunction preventing Defense Dist