Having a secretary is something one gets used to, so the faux pas was understandable, although embarrasing.

Two weeks after he retired last month, Rex Davis was invited to a luncheon in his honor at the Canadian Embassy. But as the first toasts were being hoisted, Davis was still in Alexandria, buying a light fixture at a hardware store. He had flat-out forgotten to write the luncheon down.

Forgetting is not a Rex Davis habit, largely because he has a lot to reminder.For the last eight years, he has been the chief of the Bureau of Alcohol, Tobacco and Firearms - the federal government's chief agency in the war against bootleggers, cigarette runners and misusers of guns and explosives.

Those eight years were full of bright lights and big headlines. From an agency that mostly limped after rumruners and hassled people about tax stamps, Davis turned ATF into the country's chief investigator of political terrorists and organized criminals in the booze business.

Davis was also the designated federal punching bag for the blows of the gun lobby, which was greatly displeased when Congress passed a law in 1968 requiring convicted felons and certain others to register guns.

Indeed, Davis, 54, a TNT-like retirement gift from one right-wing newspaper. Atop a story announcing that Davis was going, the paper's headline cried, with utmost objectivity: "Chief Gun-Grabber Retires."

Now that retirement has actually happened, Davis is mulling three job offers in the private sector, and reminiscing. But by his own description, his eight years of fielding big issues and administering a staff of almost 4,000 were not the most exciting of his 29-year federal career. Everyone starts somewhere, and Rex Davis started as a Treasury Department moonshine raider in Oklahoma.

He spent nine years at it - busting up barrels with an ax, staking out moonshiners in the woods all night, once facing a loaded and cocked rifle. It was a career fraught with danger and laughs, in approximately equal amounts. One recent sweltering afternoon, padding around his Alexandria home in tennis clothes and sneakers, Davis told it like it was - and could never be again.

The weather on the day Davis told, his tale was appropriate in reverse, for on his maiden day as a moonshine buster, Dec. 30, 1949, Oklahoma City was inundated by a blizzard.

"In Oklahoma, a snowstorm has an amazing effect," said Davis, whose voice still bears traces of his upbringing in an Oklahoma hamlet called Skiatook. "Everything comes to a stand-still."

Except federal agents. No sooner was Davis on the payroll than he and four other agents went out on a raid.

A well-bred sort, Davis had worn a suit and tie to his first day on the job. He had no time to change before the raid.

The raid netted 1,000 gallons of fermenting mash, only the first stage of what later becomes moonshine itself, but still very wet stuff. Because the agent in charge decided to save the mash for use as evidence in court, Davis had to carry it out to a truck, trip after trip, in a five-gallon jug. "Of course, my suit was throughly ruined," he remembered.

But the rookie learned quickly. Not only was his raiding uniform henceforth faded jeans, a khaki shirt and a floppy old straw hat, but Davis faced a desperate, armed moonshiner on another raid shortly after.

Stationed in the woods as a team of agents closed in on one still ("They put me, the rookie; where the man was least likely to run"), Davis suddenly confronted the still's operator and his 14-year-old son, as they were quietly trying to escape.

Davis called to the two to stop. The moonshiner grabbed for his 30-30 carbine. Davis, thinking quickly, grabbed his own pistol and the 14-year-old simultaneously. Then he talked the moonshiner into giving up. "It was the closest I ever came to shooting anybody," he said.

Another time, in a fit of cleverness, Davis thought up a way to convict a moonshiner whom federal agents were having trouble finding.

Under federal law, agents are allowed to seize any evidence they find at the scene of an arrest. On this particular bust, agents could not find the bustee. So it looked like effort for naught.

But the suspect had left his horse wandering around his property.Davis jumped right on his back and let the horse lead him.The nag did - straight to the stillmaster. "It stood up in court, too," Davis recalled.

Occupational hazards? "Ticks," replied Davis. "There you'd be in the woods, and the ticks would be all over you. It was really something." For years, or untill he took desk duty, Davis was forbidden by his wife to shower in the tub that the rest of the family used."She didn't like ticks any more than I did," said Davis.

Moonshine has gone pretty much the way of the Charleston in the last two decades, and Davis is not vain as to credit that completely to good police work.

"It's culture thing that's just fading out. Everything is going to a light, moderation thing these days," said Davis, who drinks only "an occasional vodka" himself. Where ATF made 15,000 moonshining arrests in 1959, it "might make 400 this year," Davis said.

But the very fact that moonshine raids are a dying spectacle make their memory brighter.

"It was very exciting," said Davis. "It was the kind of profession that you either love it or hate it." And tell you what, corn likker fans: Rex Davis certainly did not hate it.