Some gun makers responded by advertising handguns for women. Others found success in adapting combat weapons for civilians. Colt, which had introduced an updated version of the M-16 for the military, began selling a similarly tweaked AR-15 for the consumer market. Some parts manufacturers started selling AR-15 parts to consumers who wanted to piece together their own rifles. Other companies imported semiautomatic Uzis, a version of the Israel Defense Force weapon, for civilian use.
The look and the gas-powered mechanisms of the new black rifles offended some gun enthusiasts, who viewed them as mere high-powered toys. Even magazines like Guns & Ammo, the Vogue of firearms, had to acknowledge the initial wariness of some readers.
"The dyed-in-the-wool deer hunter watching his domain being infiltrated by these black and gray guns assumes these 'new generation' hunters are merely fantasizing 'war games' and are playing 'soldier,' " Art Blatt, a writer at Guns & Ammo, said in that 1981 issue. Mr. Blatt, now deceased, covered all types of firearms for the magazine and was himself a shotgun enthusiast.
But the gun media found ways to appeal to readers. In that 1981 article on the Colt AR-15 and similar firearms, Mr. Blatt invoked the rifles' military pedigree, "spawned in the crucible of war." He spoke of their military-level durability, speed and accuracy. In a 1983 cover article on "Bushmaster assault systems," he noted that in tests on a human-size silhouette target 10 yards away, a Bushmaster with a full 30-round magazine could be "rapidly emptied into the lethal zone."
The new rifles used ammunition — .223 caliber — that was considered too small for big-game hunting in most states. Before long, consumers were buying the guns for small game — "varmint hunting" — as well as recreational shooting called "plinking."
Some gun writers were not entirely comfortable with the rifles. In his article on Bushmaster, Mr. Blatt wrote that the guns seemed "a mite too powerful and penetrating" for home defense. He recommended the Bushmaster for police SWAT teams "in close-quarter encounters with evildoers."
Despite such reservations, the AR-15-style rifle — which is fast, modern, ergonomically designed, relatively easy to handle and produces little recoil — soon found a wide audience, be it Vietnam War veterans who had used the military version or first-time gun buyers.
"End users with minimal firearms exposure can learn to quickly become safe and proficient with the platform regardless of prior firearms experience," Mr. James, the editor at Guns & Ammo, wrote in an e-mail.
Another feature of the AR-15 is that it can be easily personalized and accessorized.
"You can take the whole gun apart and replace any part you want to without special tools, without knowing a whole lot," says Tim McDermott, a range officer at the Personal Defense and Handgun Safety Center in Raleigh, N.C. "They are Legos for guys."
IN 1976, Richard Dyke, a Korean War veteran, bought a bankrupt gun maker in Bangor, Me., for $241,000. That business grew into Bushmaster Firearms, which quickly earned a following after target shooters began winning competitions with its rifles.
"That did give us prestige," Mr. Dyke said in an interview with The New York Times in 2011. "Then we won law-enforcement contracts and started getting recognition in the trade press." (Mr. Dyke later sold Bushmaster and started another gun company, Windham Weaponry. He declined to comment for this article).
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Then, in 1994, the AR-15 hit a speed bump. Congress passed a 10-year ban on "assault weapons," which legislators defined as semiautomatic rifles that included two or more specific features, like pistol-type handle grips and metal mounts, called bayonet lugs, to which bayonets could be attached. People who already owned such rifles were allowed to keep them.
The ban made the rifles only more desirable for some consumers. To meet the demand, gun makers removed prohibited features, like bayonet lugs, and marketed them as legal alternatives.
"It was unfortunately an industrywide event where companies were openly bragging about their ability to sell guns in circumvention of the law," says Josh Sugarmann, executive director of the Violence Policy Center, a research and gun-control advocacy group in Washington.
The industry produced an estimated one million modified AR-15-style rifles during the ban — more than it had produced of the original version in the previous decade — says Gary G. Mehalik, a former marketing executive at the National Shooting Sports Foundation and at Taurus USA, a handgun maker in Miami. He denied that gun makers circumvented the law.
"If you drive 40 miles an hour in a 40-mile-an-hour zone, are you exploiting a loophole or following the law?" Mr. Mehalik asked.
After the ban's expiration, gun makers simply restored the once-prohibited features. Some companies added muscle to the rifles — to enthusiastic reviews in the gun media.
"Scoffed at for being a 'poodle shooter,' the AR has grown fangs and is now available in a variety of calibers including big bores," said an article in Guns & Ammo in 2005. "Today's ARs ride in an increasing number of patrol cars," the article said, adding that the guns' military counterparts "are turning live terrorists into dead ones in Iraq and Afghanistan."
Combat allusions increased in ads as well. In a 2008 issue of Guns & Ammo, an ad for Stag Arms, a leading AR-15-style rifle and parts maker, showed a photo of two policemen wearing bulletproof vests and helmets, carrying the black rifles. "Stag Arms rifles meet the highest standards of engineering precision and reliability," the ad said. "Just ask these guys."
An article about Stag Arms in the same issue described one of the company's models as "a southpaw's dream" and invoked "the role this rifle plays in combat."
Mark Malkowski, the president of Stag Arms, declined to comment.
Mr. James, of Guns & Ammo, said his magazine devoted many articles to AR-15-style rifles because manufacturers over time had improved the guns and introduced a variety of accessories, thereby attracting readers' attention.
"Guns & Ammo's role in popularizing the platform is purely a function of reader interest and the platform's unique adaptability for a wide range of sporting purposes," Mr. James wrote.
Pressured by investors in the wake of Newtown, Cerberus Capital Management, a private investment firm that bought Bushmaster from Mr. Dyke and has built the nation's largest gun company, the Freedom Group, announced that it would sell its gun interests. It has yet to find a buyer.
A woman wearing mirrored aviator sunglasses and a make-my-day smirk aims a hefty black semiautomatic Benelli rifle at an unseen predator. "This baby handles prairie varmints or the kind that come uninvited through your door," the Benelli Web site says of the rifle. "Chosen by the United States Marine Corps."
Gun makers seem to be competing to roll out the next civilianized combat weapon. Today, one trendsetter in handguns is a new generation of semiautomatic pistols with large-capacity magazines and other features. An ad for a pistol from Taurus USA promoted it as "the extreme-duty next-generation handgun, created for Special Operations Personnel."
Such marketing aside, the industry disavows a link between military-style guns and gun violence. Industry representatives, like the National Rifle Association, often fault news outlets for demonizing and mislabeling the rifles.
"As you should know, but your non-gun-owning friends probably don't, the guns our opponents call 'assault weapons' are not 'high-powered' when compared to other firearms," Chris W. Cox, the executive director of the N.R.A.'s Institute for Legislative Action, wrote in a 2009 article in American Rifleman, a monthly N.R.A. publication.
Some marketing executives take a different view, suggesting that the industry include warnings the way alcohol and cigarette ads do. In a blog post last month on Adage.com titled "In a Culture of Mass Shootings, the Ad Industry Shares the Blame," David Morse, a contributor, recommended that gun makers develop "more responsible ways" to present their products.
"Should we be holding manufacturers accountable?" Mr. Morse, the C.E.O. of New American Dimensions, a multicultural marketing research firm, asked in a phone interview. "The marketing messages do share in the blame because the messages are picked up and misinterpreted by the wrong kind of people."
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