Lance Cpl. Zack Cazares leaned back on his 155mm howitzer, the one with "Psalm 23" painted on the barrel, and chuckled about popping off 17 Iraqi tanks like ducks in a gallery.

"First shoot, first kill," he said, laying aside a pocket-size Bible to explain how U.S. Marine gunners pulverized an enemy column in Khafji, helping Saudis and Arab allies take back the border town.For the Marines, their success in a high-noon shootout raised confidence that artillerymen on the ground could match pilots' superiority in the air to destroy Saddam Hussein's heavy armor.

"We had real good F.O.'s (forward observers) up there, and we all just picked 'em off," said Cazares, from Dallas, waving an arm toward a crescent of howitzers deployed across the empty desert.

The battle of Khafji started Tuesday night when an Iraqi brigade rolled through a deserted border post and down a broad avenue into the abandoned town. Saudi defenders retreated at some speed.

The Marines, based 25 miles down the coast, hurried up to help.

"When we came up the road, everybody else was headed south," one young Marine recalled on Friday. "I wondered if we were the only ones who were going to fight this war."

But the Saudis counterattacked, helped by Qataris. Only a small Marine force shot its way into town to rescue two reconnaissance teams holed up in the center. For the most part, the Marines used firepower.

Cobra assault helicopters swept over Khafji, spewing rockets and Gatling gun fire. And the howitzers zeroed in.

When the 155mm guns began to blaze, a voice crackled over the radio: "That was dynamite, give me a repeat." The 1st Marine Battalion, 12th Marine Regiment obliged.

Howitzers fired dual-purpose rounds, shells that explode over a target and scatter armor-piercing bomblets.

The gunners were told they killed 17 tanks, although some were probably armored personnel carriers. That was good enough for Cazares and his Hawaii-based buddies.

"We must have scared 'em pretty bad," he said, recounting how some Iraqis surrendered and helped Marines change a tire on their vehicle. "I saw my first Iraqi - a prisoner. I hope I keep seeing 'em like that."

Marine officers could hardly mask pride at how artillery and airstrikes had repulsed the Iraqis. Officially, it was a small incursion of no military value. But it was a political coup for Saddam Hussein.

Persistent reports say that Iraqi armored columns are amassing in southern Kuwait and moving toward the Saudi border in an area 50 miles west of Khafji.

Speaking privately, officers wondered aloud at why Iraq would expose so much hardware in open country for dubious gain. They suspected that Saddam had something up his sleeve, and were glad their guns had scored.

For the gunners, it was just a for-real exercise in what they learned at Kaneohe Bay.

The unit came out on Sept. 5, a month after Iraq invaded Kuwait. It was attached to the 1st Marine Expeditionary Brigade and sent to live in the sand.

"I'm afraid we're going to be here a little longer than we expected," Cazares said. "The party's just starting."

Cazares, 24, spends a lot of time reading his Bible and writing to his two sons, Joseph and Zack Jr., who live with their mother in Jacksonville, N.C.

"We're not real killers," Cazares said, explaining that his father was a preacher in Dallas. "Other guys write `Destroyer' or something radical on their howitzers. We wrote, `Psalm 23.' "

That is "The Lord is my shepherd" psalm, and the crew takes confidence from it. As the long guns rolled off Friday, Lance Cpl. David Crowe of Stockton, Calif., yelled down from the ammunition truck: "It's not over. We're not in Kuwait yet."