The Firearm The Accused Boulder Shooter Bought Looks Like A Rifle, But It’s Regulated Like A Pistol

Too long to be easily concealed like a handgun and too short to really be a rifle, the firearm purchased by a 21-year-old Arvada man days before police say he went on a killing rampage in a Boulder supermarket defies easy categorization.

Police have not said whether that was the gun he used in King Soopers, and the confusion among witnesses and even officers on the scene does nothing to clarify it. Witnesses described it as an AR-15, the popular civilian version of a military weapon. Even police described it as a “possible AR-15,” after recovering it from inside the store, according to the arrest affidavit.

It probably wasn’t.

Instead, the gun used in the shooting appears to be a Ruger AR-556 pistol. According to the arrest affidavit, the accused gunman, Ahmad Alissa, bought one six days before the rampage. 

It is the pistol version of Ruger’s AR-556 rifle, which is the company’s take on the AR-15. Aside from being among the most popular firearms in America, AR-15-style rifles are also commonly used in high-profile mass shootings. It is easy to shoot, even for novices.

The pistol AR is a little lighter, a little less expensive and, for some gun enthusiasts, a little more fun to shoot, while still being as deadly as other guns.

The confusion around it extends to the federal Bureau of Alcohol, Tobacco, Firearms and Explosives. In the waning days of the Trump administration, that agency opened a comment period to talk about better defining what makes a pistol a pistol. They abandoned the effort after just five days when they were inundated by complaints from the gun industry and enthusiasts worried they were going to lose the right to buy it.

At first glance, an untrained eye could easily mistake the pistol version for the rifle version.

But there are differences. The pistol version has a barrel that is about six inches shorter and the total weight of the gun is six pounds, about a pound lighter than the rifle version. If it came with a stock attached to the gun it would be a short barrel rifle. But the pistol variant comes with a “brace,” which looks like a stock, but is designed to be strapped to the forearm. It is unlawful to fire it like a rifle with the brace pressed against the shoulder, according to firearm experts. 

Rick Vasquez, a former ATF firearms enforcement officer in the Firearms Technology Branch of the ATF and owner of Rick Vasquez Firearms, which does consulting and training, said there are two good reasons someone would want to buy the pistol variant.

“One way is very simple: ‘I just want one,’” said Vasquez, who is based in Winchester, VA. “The other answer would be: ‘Well, if it's a pistol it's shorter, and it's a lot of fun to shoot at the range.’”

Most people don’t need the longer rifle barrel, which would provide more accurate long-distance shots, to shoot at targets 25 yards away at the shooting range, said Vasquez.

“The undeniable fact remains: that shorter AR’s are more fun,” according to an enthusiastic review of the AR-556 pistol on a popular YouTube channel, TFB TV. “It handles like an AR and shoots like an AR.”

Pistol variants of AR-15’s are almost as popular as the AR-15’s themselves.

“It's unbelievable,” Vasquez said. “I mean, there's all different variants. If it looks like a rifle and could be made into a handgun it's been made into a handgun.”

Pistol variations of rifles aren’t to be confused with short-barreled rifles. Those have been tightly regulated since the Great Depression, partly because they were identified as the gun of choice for Prohibition-era gangsters.

“Short-barreled rifles have been regulated since the federal National Firearms Act (NFA) of 1934, and before owning one, one has to pay a special tax and go through a registration process (through the Bureau of Alcohol, Tobacco, Firearms and Explosives),” said David Kopel, an expert on firearm law and research director of the Independence Institute.

And there would be more paperwork, should the owner of a short-barrel rifle wish to drive across state lines.

A pistol variant avoids those regulations.

There has been an effort to regulate what constitutes a brace on a pistol, and define which braces are essentially a stock and which are legitimate braces to aid firing a pistol variant with one hand. ATF briefly opened a comment period on new rules, but then abruptly withdrew it five days later without further action.

ATF noted the original “intent of the arm brace was to facilitate one-handed firing of the AR15 pistol for those with limited strength or mobility due to a handicap, and to reduce bruising to the forearm when firing with one hand.” 

But in practicality, the brace is often used as a stock.

ATF also noted that if the brace isn’t used properly, then the firearm could be considered a short barrel rifle and subject to strict regulation under NFA, “particularly where the accessory functions as a shoulder stock for the weapon,” reads ATF’s rescinded guidance.

ATF did not respond to a request for comment.

Firearm trade groups applauded the move to rescind any effort at creating new guidance. 

The National Shooting Sports Foundation said it had long sought guidance from ATF on “objective criteria” for gun makers, but “The guidance proposed by the ATF last week did little, unfortunately, to clear the ambiguity that exists with subjective criteria,” read a Dec. 23, 2020, press release from NSSF. 

Still, a brace “is not supposed to be used like a stock,” said Vasquez, the former ATF agent.

It’s not clear that the Boulder King Soopers shooter used the brace as a stock. But, “if this individual used it as a stock in the commission of a crime, then he is actually using a short barrel rifle, not a handgun.”

Editor’s Note: CPR News includes the name of an alleged shooter only when it is critical to the story.