This answer cites a recent Time story (titled either Florida School Shooting: Why Civilians Started Buying AR-15s or Why Americans Started Buying Military-Style Weapons Like the One Used in the Florida Shooting) which mentions the 2010 book The Gun and cites another Time story from 1989, repeating these claims from it:
The Feb. 6, 1989, TIME cover story tried to make sense of how the gunman got a hold of a Chinese-made semiautomatic weapon in the first place. It reported that as trade increased following the normalization of relations, so did imports of Chinese copies of the AK-47, “which soared from a mere 4,000 a year as recently as 1985-86 to more than 40,000” in 1988. AR-15 sales went up too.
Also boosting sales was another one of the major domestic stories of the 1980s: the crack epidemic. “Law-enforcement officials note that the rise of semiautomatic weaponry parallels almost exactly the virtual takeover of parts of big cities by crack dealers,” the story noted. Robert Stutman, who ran the Drug Enforcement Administration’s New York State operation back then, told the magazine that “the paranoia induced by the drug, which most of the traffickers use themselves, makes them pick the best weapons available for protecting themselves, and they have the money for it.”
Then, when the police couldn’t match the dealers’ firepower, citizens who felt unsafe started buying these weapons themselves for self-protection:
The final and most dismaying turn in this cycle: responsible, law-abiding citizens — afflicted by a lack of confidence in the police, reading every morning and watching on TV every night the stories about shootouts endangering innocent bystanders — start arming themselves in case they have to join the battle. It used to be that the great majority of American gun owners bought their weapons for hunting or sport (target shooting, for instance). But recent surveys show nearly 50% mentioning self-protection as their primary reason. Says Mark Warr, a sociologist at the University of Texas: ”It’s a giving up on the system. People have lost confidence in the ability of local government to control crime. There is a growing feeling that ‘We must do it ourselves.'”
- Did most crack traffickers use the drug themselves?
- How commonly did use induce paranoia, and how severely?
- Did crack traffickers favor what Stutman calls "the best weapons available" ("military-style weapons," AR-15s, or AK-47s) over other, more affordable weapons?
- Was drug-induced paranoia among dealers the major cause of dealers purchasing what Time calls "military-style weapons," instead of other kinds?
- Were crack dealers/traffickers' purchases a significant factor in the increase in sales of "military-style weapons"?
- At what point in time had "the great majority of American gun owners" not bought them primarily for self-defense? Did the absolute number of hunters decrease between then and the year 1989, and/or did the number of self-defense-motivated owners increase?
- Were police outgunned by crack dealers in the 1980s?
- Was fear induced by media reports a significant factor in the adoption of "military-style weapons"?