Advancements in 3D-printing technology have yielded increasingly reliable 3D-printed firearms, many of which require no federally regulated components to function. Making a gun from scratch at home required thousands of dollars of machining equipment and years of engineering expertise.īut in recent years, that has begun to change. For decades, weapons manufacturing has been the domain of arms industry heavyweights: Glock, Sig Sauer, Remington, Sturm, Ruger & Co.