(CBS) — Guns and ammunition are disappearing off store shelves in the Chicago area.

Is it fueled by gun-ban fears, or something else? CBS 2’s Courtney reports.

Several gun store owners say they started noticing a surge in sales after mass shootings like the ones in Aurora, Colo. and Newtown, Conn.

To add fuel to the fire, customers really began flocking to their stores when politicians started talking about making changes to gun laws.

Empty cases, bare shelves, and a phone that’s been ringing off the hook – that’s what things have been like for Don Mastrianni inside his Elmwood Park gun store.

“You can’t get them in here fast enough. As a matter of fact, for a while, I was selling things before I actually got them,” Mastrianni, owner of Illinois Gun Works, says.

He tells CBS 2 the state’s proposed assault rifle ban and President Obama’s vow to address gun laws has sent him customers by the dozen. They’re buying whatever they can get their hands on, he says.

“A lot of the politicians really are the gun industry’s best salesman, because anytime they threaten to make some kind of regulation, everybody runs out,” Mastrianni says.

Bernadette Terry, co-owner of North American Firearms in Lombard, is noticing the same thing. She says even ammunition is now hard to come by.

“Anything that has high-capacity availability: gone. People are grabbing it because they don’t’ think they’ll be able to get it anymore,” Terry says.

State Sen. Dan Kotowski, D-Park Ridge, says he believes gun sellers are using such rhetoric as a marketing ploy to help boost sales. He is sponsoring the bill to ban assault rifles in Illinois.

Gun store owners tell CBS 2 they’re having a hard time replenishing their supply because most nationwide distributors are also out of stock.