The May 4 front-page article “How military rifles got to be a civilian commodity,” about the company Blue Sky Productions’ importation of M-1 rifles, stated that “the modern tale of military-style weapons in America opens on Capitol Hill, in mid-1984.” Josh Sugarmann of the Violence Policy Center was quoted as saying that the 200,000 rifles imported by Blue Sky were “basically the first of the military weapons marketed to the civilian population. If you were going to draw an ‘assault weapons timeline,’ it would start with the M-1 and eventually end up where we are today.”
I would suggest the Civilian Marksman Program (CMP) as a much earlier source of military weapons sold to civilians. The CMP has been selling military-style weapons to citizens since the early 1900s. The CMP was created by Congress to provide civilians a chance to develop marksmanship skills in case they were drafted. It was run by the government until the mid-1990s, when it became a nonprofit organization. The CMP still gets military surplus guns and sells them. It also promotes gun safety and youth gun training.