On Tuesday, President Trump tweeted “I am looking into 3-D Plastic Guns being sold to the public. Already spoke to the NRA, doesn’t seem to make much sense.” The president, lawmakers, and many Americans have targeted 3D-printed guns as the latest menace to society. Perhaps they should also direct their attention at books such as the Improvised Munitions Handbook that are easily accessible as free PDFs and contain DIY plans for guns and much, much more.

After all, you didn’t need to wait for 3D printers or fancy plans to know how to build a gun at home, or even to build several and arm your friends. Instead, you can find a free online copy of that old army handbook and just open to the section on firearms.