When U.S. soldiers need to penetrate a tank's armor from a mile away, they count on a weapon that evolved from the garage tinkering of a former wedding photographer.

The .50-caliber rifle created by Ronnie Barrett and sold by his company, Barrett Firearms Manufacturing Inc., is the most powerful firearm civilians can buy. It weighs about 30 pounds and can hit targets up to 2,000 yards away with armor-piercing bullets.

That kind of power has drawn a customer base of gun enthusiasts, Hollywood actors and Barrett's most loyal buyer, the U.S. military, which has been buying Barrett's rifles since the 1980s and using them in combat from the 1991 Gulf War to the present.

But the powerful gun has drawn plenty of critics, who say the rifle could be used by terrorists to bring down commercial airliners or penetrate rail cars and storage plants holding hazardous materials.

For years some state and federal lawmakers have sought to limit or ban the gun's sale, as California did this year.

Tom Diaz, a senior policy analyst with the Washington-based Violence Policy Center, says the guns should be more regulated and harder to purchase. The gun can now be bought by anyone 18 or older who passes a background check.

"They're easier to buy than a handgun," Diaz said. "These are ideal weapons of terrorist attack. Very dangerous elements gravitate toward these weapons."

The majority of Barrett's sales come from military orders, for armed forces and police departments in some 50 allied countries. Every branch of the U.S. military uses the rifles, and the Department of Defense last year spent about $8 million on his firearms, Barrett said.

Barrett estimates about 1,000 of his rifles — which each cost between $3,500 and $10,000 — have been used in both the 1991 Gulf War and the current war in Iraq.

The guns are used by most civilians for hunting big game and in marksmanship competitions. Civilian sales are crucial to business because military and police orders can fluctuate year to year, Barrett said.

"It's like, what does a 55-year-old man do with a Corvette? You drive it around and enjoy it," said Barrett, 51, whose customers include doctors, lawyers, movie makers and actors. "I know all the current actors who are Barrett rifle shooters, some Academy Award-winning people. But they don't publicize it. They love to play with them and have fun. Shooting is very fun."

A 1999 investigation by the U.S. Government Accountability Office found the rifles were available on civilian markets with fewer restrictions than those placed on handguns. Ammunition dealers were willing to sell armor-piercing bullets even when an agent pretending to be a buyer said he wanted the ammunition for use against armored limousines or "to take a helicopter down."

Other reports have observed the rifles have made their way to terrorists, drug cartels and survivalists.

Joseph King, a terrorism expert at the John Jay College of Criminal Justice in New York, said terrorists could use the weapon to take out a plane.

"I don't understand what good a .50-caliber is going to do you," King said. "I don't understand any civilian use of it. The only thing it's good for is for military or police application. You can't really hunt with it because it would destroy most of the meat."

Barrett and gun advocates say the gun's power has been exaggerated and doesn't pose a threat to citizens because the weapons are too expensive and heavy to be used by criminals.

Barrett and other gun advocacy groups heavily lobbied the state of California, the first state to pass a law making it illegal to make and sell the gun. Several other states and some federal lawmakers have introduced similar legislation.

Despite these efforts, Barrett says sales are up nearly $6 million from last year thanks to recent military and police orders.

The New York City Police Department recently announced it's training officers in its aviation unit to use the rifles, which will be on board some of the department's helicopters to intercept potential attacks from boats or airplanes. In 2002, the Army placed an order for 4,200 of the guns, Barrett said.

Other manufacturers now make the gun, but Barrett dominates the market.

In the next few years, he said he plans to more than double the current number of employees, 80, and the size of his 20,000-square-foot gun-making facility located in Murfreesboro, about 30 miles southeast of Nashville.

A lifelong gun enthusiast, Barrett never went to college and worked as a commercial photographer and reserve deputy for years before he started tinkering with the .50-caliber Browning Machine Gun in the early 1980s.

The heavy recoil of the Browning made it nearly impossible to shoot without it being mounted on a turret, but Barrett's rifle reduces recoil to the point where it can be shoulder-fired, while the weapon rests on a bipod.

Barrett says he was nearly $1.5 million in debt at one point trying to get the business on its feet. He sold his first guns to the military in the late 1980s and the long-range weapons gained popularity after they were used to attack Iraqi tanks in the 1991 war.

Barrett's son, Chris, who works with his sister at their father's business, said he watched his dad build the gun in the family garage and is not surprised by the growth and success of his father's business.

"He's worked hard all his life. I think he would do as well at anything he pursued," Chris Barrett said. "He's not one of these big suits, a CEO at the top of one these big money machines. He's not one to back down. He can make anything work, no matter what he's doing."