What features/mods are necessary to make a semi-auto that is approved by ATF?
The receiver must be “permanently attached to the trunion, bottom plate and top plate by means of deep penetrating, full fusion, gas or electric steel seam welds” when finished. A new right side plate needs to be created that is approximately .065 inches thicker than a normal 1919 machinegun side plate. This is to ensure that the finished product can not be easily converted to full auto. See blueprints and images here. For additional information, see the ATF Approval Letter that American Arms received. • Can a home-built 1919a4 ever be sold? Yes, but any profit must be declared on taxes. • How many home-built guns can one make in any given time period? One per year for a semi auto. • Does there need to be name, serial number, date of mfgr, and place of mfgr if I build my own? Yes. • Is welding the receiver necessary for the home builder? Yes. See the above question for additional details. • Can I own a semi-auto with a full-auto parts kit to be used as spare parts? Or do all parts kits
