OKLAHOMA CITY — Bryan Hull will soon strap his Smith & Wesson .357 Magnum revolver to his hip and meet his armed friends at Beverly’s Pancake House here. They have no interest in the cash register. They just want a late-night breakfast.

A new law takes effect on Thursday in Oklahoma — anyone licensed to carry a concealed firearm can choose to carry a weapon out in the open, in a belt or shoulder holster, loaded or unloaded. Five minutes after midnight Thursday, Mr. Hull and his friends — supporters of the Oklahoma Open Carry Association, a gun rights group — will mark the occasion by wearing their unconcealed handguns while dining at Beverly’s, a 24-hour restaurant.

“It’s just a peaceful assembly,” said Mr. Hull, 44, the association’s co-director. “We’re all licensed by the state to carry. We’ve all been trained and vetted. Why wouldn’t somebody want to have that kind of a group do business with them in their establishment?”

In a state with 142,000 men and women licensed to carry concealed weapons, the scene at Beverly’s will most likely become commonplace as Oklahomans take advantage of the law by displaying their handguns while they shop for groceries, eat at restaurants and walk into banks.