This despite news the investment firm that owns Bushmaster said it would sell the company, and Dick's Sporting Goods and other national retailers have pulled the weapon from shelves out of respect for the 26 dead at Sandy Hook Elementary School.
Andrew Molchan, director of the National Association of Federally Licensed Firearms Dealers, told ABC News Wednesday the gun's recent attention following the shooting at Sandy Hook has had an effect.
"Naturally, when something's a lot in the news, it has increased sales," Molchan said. "I doubt there's much inventory left at this point. There are no discounts, that's for sure."
Adam Lanza, 20, took the rifle and two other handguns from his mother's collection and used it to kill her and 26 people at a nearby elementary school -- 20 of the victims being first-grade children -- before killing himself. The Bushmaster, a civilian model of the M-16 assault rifle commonly used by members of the military, was his primary weapon.
Gun collectors say the Bushmaster and other AR-15s made by Smith & Wesson, Colt, Remington, Ruger and Olympic Arms have always been a popular gun, partly because former military members have been trained to use it. It is also highly customizable, with a variety of grips, scopes, flashlights and other tweaks that allow an owner to personalize their assault rifle.
Ross Meyer, owner of Gunworld & Archery in Elko, Nev., told ABC the AR-15 is "the Barbie Doll of rifles" for the number of accessories that can be bought.
"You can add scopes, flashlights, lasers," he says. "You can really tech it out. And being semi-automatic, it's fun to go out and shoot."
The increased talk of renewing the nation's ban on assault rifles is also driving the number of sales, with gun owners wanting to get theirs before a potential ban is put in place, ABC said.