FAZENDA CAPAZ, BRAZIL -- Buckshot fired at a 10 paces from a 12-gauge shotgun makes a hole the size of a man's hand in a hardwood door. One round can drop an Amazon jaguar or lift a grown man off his feet. So in a way, you could say that John Davis was lucky.

When the Ford coupe braked that midnight by the front door and the gun roared, he had time to turn from where he was standing guard and take a few steps into the house. He was only slightly wounded.

Today, John Davis III, a gangly 16, showing the first traces of whiskers, laughs off that assault six months ago on the family farm in the Brazilian Amazon. In this surly backcountry, feuds over land abound and scores often are settled in blood. It was not the first violence to touch the Davises.

The trouble dates back three generations, to the days of John's grandfather. In 1961, John Weaver Davis, a Mississippi farmer and Presbyterian minister, was casting about for a place to raise a family and continue the Lord's work. A fellow churchgoer told him about Brazil's northern frontier, a "paradise" of bounteous lands and squalid poverty -- fertile ground for planting crops and God's word. The agricultural missionary, who had fled the Belgian Congo in the tumult following Patrice Lumumba's 1960 revolution, jumped at the chance.

The burly evangelist farmer bought 250,000 acres in the northern state of Para, in the central Amazon basin. He called it Fazenda Capaz, a handsome spread appointed by stately palms and towering Brazil-nut trees, and traversed by the Blue River.

Little did Davis know that he had set down in a battlefield. Shortly after he bought his farm, hundreds of squatters moved in. In July 1976, Davis and his sons Mallory and Bruce were shot down in a hail of bullets during an apparent ambush by some 60 squatters. The sons died immediately; the pastor suffered for nine days in a hospital bed before lapsing into coma and death. To this day, no one has been convicted of the crime, and surviving Davises have known but a few interludes of peace ever since.

The Davises are unusual victims in Brazil's spreading land wars only in that they are of U.S. origin. Although violence is a traditional feature of the backlands, conflicts over property claims have spread to all 25 states and territories.

In 1985 and 1986, almost 300 Brazilians were killed in land-related disputes, according to the Land Pastoral Commission, which is linked to the Roman Catholic Church. This year, more than 100 have died in clashes between squatters and land owners or their hirelings.

In late August, on the plains of Goais, the Rev. Francisco Cavazzutti, a priest known for his work with the landless, was hit in the face by a shotgun blast as he walked to his car after saying evening mass. Doctors said he probably will be blinded for life.

In June, Paulo Fontelles, a Para State congressman and attorney who often represented squatters, died of 11 bullet wounds in the head. The leading suspect, a Para rancher, allegedly was evening the score for the murder of his son in a shootout with squatters last year.

One of the most brazen killings was that of the Rev. Josimo Tavares, another priest who defended the landless, shot dead last year in the main square of Imperatriz, a city of 200,000. The pistoleiro admitted working for a big rancher. His bounty: about $2,000.

The violence results in part from of an agrarian reform program that has convulsed and confounded Brazil almost before it has begun. Just after President Jose Sarney took office in March 1985, he announced plans to confiscate idle estates from land barons and distribute millions of acres to 7.6 million landless peasants.

The plan met with fierce resistance from the big farmers, who denounced it as too radical, and from Catholic liberals and the left, who branded it too tame. While hopes and tempers flared, the vaunted program unraveled.

Three agrarian reform ministers have come and gone in 30 months. The first two fell prey to the political cross fire between the powerful lobbies of the landed and the landless in Brasilia. The third, Marcos Freire, was killed, along with six top aides, in September when an Air Force jet crashed in the jungle.

Of the 450,000 families that were to be settled by end of this year, 37,000 have received plots. Dozens of projects await settlement in courts.

In the Constituent Assembly, where Congress is drafting a new constitution, both the left and the landed have been well represented. Dozens of members of the Rural Democratic Union, organized by the rancher gentry, packed the galleries alongside leftist and priests. Half a dozen amendments were proposed, torn up, and pasted together again.

The new land law will not be ready until Congress votes on the finished constitution early next year, but the liberals recently got a stern rap on the knuckles. The armed forces minister, Gen. Leonidas Pires Goncalves, lectured Sarney's Cabinet that the constitution was being "conducted by an active minority" against the "desires of the moderate majority of Brazilian society." In a country that recently finished two decades of military rule, such admonitions are not taken lightly.

As Congress backs and fills, the tensions in the countryside have only heightened. In the Amazon, migration is intense and justice uncertain. About the time that Davises settled in Para, the Brazilian generals were determined to open new frontiers, exploit the vast mineral riches and create a "security cordon" of settlements along the borders.

The government built hydroelectric stations, giant bauxite and iron mines, towns and airports. Thousands of Brazilians, from rich developers lured by tax breaks to starveling peasants in search of a few fertile acres, answered the call.

In the span of a decade, Brasilia had started the biggest land rush in the Americas since the United States' push west of the Mississippi. Soon, there were many more pilgrims than plots to settle them on. Many pioneers failed, selling out their stake and squatting on someone else's. Often, deeds were vague and disputed.

"Every place in Amazonia belongs to someone, but few have a legal title," said Gen. Euclydes Figueiredo, who commanded Amazon regiments for several years and befriended the American minister. "Even those that do, like John Davis, have no guarantee of protection."

Ironically, the pastor's children managed on a modest scale the sort of agrarian reform that has eluded Brasilia for years. The family settled its feud with the squatters, selling off 200,000 acres to more than 1,000 invaders and buying out the rest.

Only one family, headed by Marcelino Mendes de Andrade Gusmao, a well-heeled rancher with a reputation for ruthlessness, refused to budge or buy. Although nearly every important official in Para has upheld the Davis' property lines, Gusmao has steadily expanded his claim to the Davises' farm. "Mr. Gusmao is opposed to buying something which he considers his," argued his attorney, Carlos Platilha.

The Davises, for their part, cite acts of vandalism, which they say the Gusmaos have launched over the past 18 months. Last January, witnesses said Gusmao's sons invaded Dan Davis' farm, ran off the workers with gunshots and set ablaze the farmhouse and a tractor.

Last March, after young John Davis was wounded by the shotgun blast, allegedly fired by another of the Gusmao clan, Army troops were moved onto Fazenda Capaz for two months of maneuvers, but also to discourage attacks on the family.

The Davises charge that state and legal authorities have sided with the Gusmao clan. Gusmao's lawyer, Carlos Platilha, originally represented the Davis family, a swap that an attorney here called "at best, unethical."

In August, the Davises said, 27 federal police -- riding in private vehicles driven by Gusmao's three sons -- pulled into the ranch. By this account, a lieutenant slapped Jan Davis and seized her husband Dan and John Jr., and, without explanations, hauled the brothers off to jail.

Two days later, a judge discovered the prisoners were being held without charges and ordered their release. In early October, unidentified gunmen shot several rounds over workers' cabins here.

Through three generations, seven lawyers, and six state governors, "the Davis case," as Brazilians dubbed it, smolders on.

"Brazil is our home. We have no plans to leave," said John Davis Jr., 42, the pastor's oldest surviving son. He has the sinewy muscles of a farmer and his father's penetrating eyes.

On a muggy Sunday, after the regular family prayer meeting, two dozen towheaded children sprawled in a circle on the farmhouse floor, reciting passages from well-thumbed Bibles and belting out hymns. It could have been some painter's tropical idyll, but for the bullet holes in the water tank, the charred tractor, and the tension that coursed through the room whenever a car passed.

"We can only trust in God to protect us," Davis said.