SACO – When U.S. attack jets and helicopters fired off thousands of rounds at enemy targets in Iraq, the odds were good that those deadly rapid-fire weapons were made in Maine.

General Dynamics Armament and Technical Products Co. is in the business of manufacturing high-tech, and highly lethal, weapons used by American troops and military aircraft. Most of the General Dynamics-made weapons used in Iraq were made at the company’s plant in Saco.

On the ground, troops in Iraq are using MK19 grenade launchers and M-2 machine guns that were manufactured in Saco. In the air, F-15, F-16 and F/A-18 fighters use Gatling guns assembled at the plant.

A-10 “Warthog” warplanes and Cobra attack helicopters are equipped with Gatling guns manufactured at General Dynamics’ Burlington, Vt., plant before the company bought the Saco facility three years ago.

These are serious weapons.

The MK19’s explosive grenade cartridges fire at a rate of more than 300 per minute and can penetrate armor more than a mile away. The Gatling guns on U.S. aircraft have firing rates of up to 6,000 rounds per minute and enough power to take out enemy tanks.

The Saco plant has manufactured and assembled tens of thousands of the weapons over the years.

“With the exception of the Apache [helicopter], if it’s an aircraft and has a gun, it’s ours,” said Phil Hynes, vice president of strategic planning for General Dynamics Armament, based in Burlington.

General Dynamics Armament is a division of Virginia-based General Dynamics Corp., which is the parent of Bath Iron Works, the Maine shipbuilder that has 22 of its destroyers, cruisers and frigates deployed to the Middle East.

In Saco, General Dynamics’ 240 employees manufacture and assemble a variety of weapons, which are also tested at the plant.

The guns in the F-15, F-16 and F/A 18 fighter jets are primarily used in dogfights, which have not occurred in Iraq, said Christopher Hellman, a senior analyst with the Center for Defense Information, an independent research organization in Washington.

It’s a different story, he said, for the guns on the Cobras and A-10s. The A-10s have been described as “flying Gatling guns” because of their 30 mm seven-barreled guns capable of firing up to 4,200 rounds per minute. The rounds are designed to pierce tank armor.

“When you get to the A-10s and the Cobras, that’s the centerpiece of their armament,” Hellman said. “And they’re playing a critical role as our ground forces move forward. I can’t envision the Marines moving forward without them.”

The Saco plant, which has been around for more than 50 years, was purchased by General Dynamics from New Colt Holding Co. in 2000.

The sprawling 450,000-square-foot plant, which is currently off-limits to reporters and the public, is set among some woods across the street from an elementary school. Its parking lot abuts a residential neighborhood.

The plant has produced more than 25,000 MK19s since the late ’80s, and thousands more M-2 machine guns, Hynes said. It has also assembled hundreds of the Gatling guns used on military aircraft.

There will be more to come.

General Dynamics, which calls the Saco plant its “Center for Excellence for Armament Production,” was awarded a contract in February for $9.8 million for 633 MK19 grenade launchers. In January, McDonnell Douglas Corp. awarded the company an $18.9 million contract for Gatling guns for its F-15 aircraft program.

And last summer, it was awarded a $37 million contract from the Navy for gun systems for the F/A-18s.

General Dynamics is also developing the gun system for the next-generation F-35 Joint Strike Fighter that is scheduled to be ready for service in 2008. Those guns, too, will be manufactured in Saco.

The company is also working on a military contract to develop the next generation of grenade launcher, also to be manufactured in Saco.