Have you heard the one about the traveling salesman who found God and gave up a career selling military weapons to operate a Virginia farm for handicapped children?

Donn Grand Pre has heard that one because that's just what he did. Three years ago he quit a $40,000-a-year job at the Pentagon where he was one of an elite corps of 16 federal arms salesmen. In Europe, the Middle East or Africa, Grand Pre was the man to talk to if you needed to supply an army with rifles, tanks or jets. To hear Grand Pre tell it, selling military hardware was a glamorous life.

"We looked on ourselves with some pride as the 'merchants of death' or 'the Pentagon drummers,'" says Grand Pre, 53, of his 10 years with the Defense Department's international military sales office.

In the capitals of such countries as Saudi Arabia, Pakistan, Iran, Zaire and Italy, he sipped vintage wine with heads of state and partied with weapons industry representatives whose expense accounts seemed unlimited. It was a world of staggering profits sometimes earned with the help of payoffs and blackmail. And while his family life crumbled back home in Arlington, Grand Pre chased big deals and beautiful women.

Today Grand Pre raises some crops, cattle and horses on 300 acres on rolling Madison County, Va., countryside that offers a panoramic view of the Blue Ridge mountains. He and his wife, Cellas, also work with deaf and blind children under the auspices of a tax-exempt, charitable organization they founded.

That sea change in his life is described imprecisely in a book, Confessions of an Arms Peddler , to be released next month by Chosen Books, the publisher of Christian titles for whom ex-White House tough guy Charles Colson wrote his best-selling Born Again. Grand Pre condenses time and disguises characters for the sake of telling his story, but his conclusion is clear: the arms race is a godless pursuit fueled by men and industries interested in the almighty sale, by men who know about weapons, by men like Donn Grand Pre.

"I'm very much for a strong defensive capability, and I'm talking about the defense of the United States and our self-interest," Grand Pre says. "But I'm against the proliferation of weaponry just for the sake of maintaining production lines or making the sale. Because the thing snowballs. We find that occasionally we're arming both sides of a confrontation, as we have in India and Pakistan, Jordan and Israel and -- on a much larger scale -- Egypt and Israel."

A North Dakota native, Grand Pre is a retired colonel in the military reserves. He served in the Pacific theater during World War II and was wounded in Korea. A former North Dakota newspaper editor and sporting goods store owner, he went to work at the Pentagon as a civilian at the suggestion of an old Army buddy. In 1966 he got involved in an arms sale to England, and he eventually became responsible for selling American weapons to other countries.

Arms deals, Grand Pre says, are complicated affairs that naturally attract representatives from such companies as McDonnell-Douglas, General Dynamics, Northrop and Lockheed, as well as free-lance salesmen who stand to profit by selling ammunition or replacement parts to countries purchasing major weapons systems. The competition is wicked. Grand Pre says twice an independent buyer and seller set him up for blackmail, once splicing a tape of a conversation in an incriminating way, another time by secretly taping a romantic interlude he had with the arms dealer's girlfriend. He says he once turned down a $150,000 bribe aimed at getting the United States to buy a huge amount of ammunition from Italy, though he was well aware of under-the-table arrangements everywhere.

"When we were negotiating in Kinshasa (Zaire) with Mobutu," Grand Pre says, "his personal friends were there and the signs were practically on the walls saying who you had to pay off. What we'd do is work with the private contractor who knew the right people, and they would handle that, or, as they would put it, they would 'orchestrate' it. If you didn't pay off the right guy, the British, French or Germans, would."

While Grand Pre was bargaining in exotic parts of the world, he and his wife became strangers. She didn't tell him she was taking cobalt treatments for cancer of the thyroid. His sons experimented with marijuana. He put on weight, grew cranky and worried. A Catholic priest who married the Grand Pres urged him to consider his life.

Then one September evening in 1975, after a second attempt on his life, Gerald Ford went on television to suggest something might be wrong in a country where a president coudn't walk down a street without fear of getting killed. That hit Grand Pre, he says, and he decided society was being divided into welfare and warfare states: "Unless the guy in the saddle does anything about it, it'll continue ad infinitum. It was time to unload."

Two years ago Grand Pre took six weeks off and decided to retire. Friends introduced him to editors at Chosen Books and he attended a writers' workshop for Christian authors. Today he rides horses and writes; he has two novels in progress along with a less personal but more detailed book on the international arms trade, The Golden Calf . But he doesn't expect to name bribers or bribe-takers he has known: "Probably having been so close to selling myself for a bag of gold," says Grand Pre, "I can appreciate their position and don't feel comfortable pointing an accusing finger."