In the latest in a string of legal battles over gun control, Rocky Mountain Guns Owners (RMGO), a pro-gun group, is challenging Colorado's large-capacity magazine ban in court.

The state's ban on large-capacity magazines, devices that can hold more than 15 rounds of ammunition, was one of a handful of gun control measures passed in 2013 in the aftermath of the Aurora theatre shooting.

Credit Rocky Mountain Gun Owners

"It was a reaction. An emotional reaction in the legislature to a tragedy and it's bad public policy. (...) We're really arguing that it's unconstitutional and it's ineffective. It's not going to stop mass shootings," said Dudley Brown, the executive director of RMGO.

When asked for the source of the data behind the assertion that magazine bans are ineffective, Brown said there are "many, many data sources."

"One of them, in the state of Virginia, they have data from the entire 10-year magazine ban on a federal level," he said. "And it showed no change in the number of high capacity magazines that a criminal was carrying when he was arrested for other crimes. So, what we found is that criminals were still carrying high capacity magazines, even during the ban."

Brown also pointed to a recent legal decision in California as an indication that there could be a favorable outcome in Colorado. Last July, a California law limiting gun magazines was set to go into effect, but a federal judge granted a preliminary injunction so that a lawsuit could move ahead. A federal appeals court later upheld the injunction.

In Colorado, there have been lawsuits against the ban since it passed. In 2016, a federal appeals court rejected a lawsuit against the ban brought by dozens of sheriffs, ruling that they hadn't shown the law had harmed them enough to sue. In the legislature, lawmakers have attempted to repeal the ban several times.

The Colorado Court of Appeals will hear RMGO's case Wednesday afternoon. Brown says that if the group loses its appeal, it will continue to fight the magazine ban at the legislative level.