Starbucks Corp. and some other chain stores in the U.S. are finding themselves caught in the middle of a firearms debate, as gun-control advocates go up against a burgeoning campaign by gun owners to carry holstered pistols in public places.

The "open carry" movement, in which gun owners carry unconcealed handguns as they go about their everyday business, is loosely organized around the country but has been gaining traction in recent months. Gun-control advocates have been pushing to quash the movement, including by petitioning the Starbucks coffee chain to ban guns on its premises.

. . .

"The concealed carry movement has been successful but open carry is coming up," in popularity, said Mike Stollenwerk, a retired Army lieutenant colonel and co-founder of the site.

. . .

Home Depot Inc., Best Buy Co. and Barnes & Noble Inc., are designated as "open-carry" friendly in some online forums or say they abide by existing laws. "Our practice is to comply with local and state laws," said Best Buy spokeswoman Sue Busch Nehring.

Open-carry proponents are also taking advantage of some momentum in state legislatures to expand gun rights, although most new and pending measures don't specifically address unconcealed handguns.

Open carry hasn't been part of the official focus of the pro-gun lobbying group, the National Rifle Association, which has 4 million members.

In the past 20 years, the NRA has focused on expanding the ability of U.S. gun owners to carry a handgun in a concealed manner.

Today, 38 states have a "shall issue" permit process. Two states don't require a license to conceal carry. Eight states have "may issue" concealed carry laws, meaning permits will be given with the discretion of a local politician or police officer.

"We support the self-defense rights of law-abiding Americans in accordance with local, state and federal laws," says Andrew Arulanandam, an NRA spokesman, who declined further comment on open-carry activity.