MILLSBORO, Del. - Wayne Sennett was sitting on his 7-ton contraption named Poor Attitude yesterday, having just shot a pumpkin 2,496 feet over a soybean field before a crowd of thousands.

Some people might think that's pretty impressive, even for an air cannon, the lion of the pumpkin-hurling world. But to the world-class "punkin chunkers," those who migrate here each year with hulking machines that resemble medieval artillery, there is only one measurement that could bring true happiness: 5,280 feet, the elusive one mile.

"Tomorrow there will be redemption; I have every intention of shooting a mile," he said, promising to hook up his secret weapon, a 1981 Ingersoll Rand compressor that he calls "Ol' Smokey."

"When she comes under her load, black smoke just rolls. You think you're looking at an old Northern-Southern coal train," he said.

Sennett and hundreds of fellow techno-tinkerers faced off here in southern Delaware yesterday during the 17th annual punkin chunkin world championship. They came from as far as Florida and Illinois, hauling 80 machines with names such as Second Amendment, Jack-O-Splatter, Spookey Bazooky and Bad Hair Day - machines made of junkyard scrap metal, flatbed parts, PVC pipe, barbell weights, an oil tank from someone's backyard swamp. Their quest: to make a pumpkin fly farther than anyone else.

The event, which started in 1986 as a dare among four local guys, has evolved into the state's third-largest tourist attraction, after the state fair and NASCAR racing, and is expected to draw 25,000 spectators over the weekend. The competition has raised hundreds of thousands of dollars for scholarships and local charities.

Annual competitions modeled after this one have sprung up around the country, in Pennsylvania, New York, Ohio, North Carolina, Illinois, Indiana, New Mexico, Oregon and Colorado. But the Delaware event remains the sport's granddaddy, meaning if you want to be a world champion chunker, you have to win here.

Ask a chunker why, and you'll get everything from a lecture on pneumatics to a dose of testosterone.

"Where else can you go around with a 10-inch [wide] truck-mounted cannon and not have it taken away from you?" said Trey Melson, 51, one of the founders of the competition. His Universal Soldier is a camouflage-colored vehicle with a 1977 Oldsmobile station wagon atop an Army truck, with an air cannon mounted on the back. It took second place in last year's competition, and hurled a pumpkin 3,631 feet yesterday, placing second in preliminary rounds.

"It's the biggest legal rush you can probably get," said Joe "Wolfman" Thomas, 54, of Milton, the two-time air cannon world champion, who was back with Old Glory yesterday in hopes of a third title. But in the first of three rounds, his pumpkin exploded in pieces as it left the cannon, a situation known as pumpkin pie. "You can feel the power coming right out of it."

The sport started when four friends challenged each other in a chucking contest. They started throwing anvils, but that was hard on their backs. One of the guys, Bill Thompson of Georgetown, Del., loved the type of medieval siege machines used during gladiator wars, and suggested hurling pumpkins since they were cheap after Halloween.

The friends built their machines and met on a farm. One was a mix of ropes, tubes and pulleys; a second was various garage door springs connected to a car frame. A third was a wooden pole mounted on a trailer, powered by auto springs. The winning throw that year was 128 feet.

By the third year, the machines had outgrown the field - the pumpkins were landing in the woods - so the site had to be moved. Sixteen years after that first competition, last year's winning throw was 3,911 feet.

Now, there are various categories of machines, including trebuchets - which use counterweights suspended in air - catapults and air cannons, which can send pumpkins hurling at more than 600 mph, so fast that the pumpkin typically can't be seen coming out of the gun - only as it arches through the air hundreds of feet away. A youth division attracts students and their science projects.

"It goes back to building the better mousetrap," said Marc Banka, a mechanic from Durham, N.C., who with his brother Tony built Pumpkin Slayer, a spring-powered machine that uses a bicycle to tense the springs.

"So many things that are built have already been done, they're corporate. You're trying to show that you're smarter than the next guy."

Though many of the competitors are still people who work with their hands - such as mechanics, plumbers, welders and pipefitters - more engineers are entering the sport, and some teams get corporate sponsorships, a notion that purists disdain.

The rules are essentially this: Pumpkins must weigh between eight and 10 pounds and must be intact when they leave the machine. Explosives are prohibited. Distances are measured by spotters who ride on four-wheelers in the field.

There's no rule governing where the pumpkins are grown, and the Second Amendment crew brought their own this year, grown by a minister who oversees a mission in Cuba. The Cuban pumpkins are pale white and hard as bowling balls, and thus more resistant to high pressure.

The machines aren't wasted the rest of the year. Some chunkers amuse themselves throwing watermelons and cabbage, too.

Frank Payton, 44, owner of Southern Exposure, hosts a toilet toss each May on his Milton farm (local plumbers keep him supplied with old toilets). On Labor Day weekend, he and his buddies toss beer kegs. Once in a while, they hurl microwaves.

On a crisp autumn day, with the smell of barbecue in the air, the competition lived up to its reputation yesterday as the world's biggest tailgate party (despite the frequent cannon blasts that literally made people jump). For the chunkers, many of whom bring their machines to other state competitions as well, friendships are fierce but competition is fiercer.

"These boys are all my friends till I walk up to that gun," Sennett said. "When it comes time to pull that trigger, the friendship ceases and desists."

The championship, which ends today, is accompanied by a festival, which features a chili cook-off recipe contest and live music. In accordance with tradition, a couple got married yesterday. Despite the chill in the air, spectators watched with rapt attention, pointing at the sky to follow each speck that was a flying pumpkin.

"It's great what happens when someone has too much time on their hands," said John Frost, 36 who came from Cecil County with his family.

Others complained that the event has outgrown some of its charm.

"It was like a joke to begin with," said Sharon Peterson of Millsboro, who has been coming since the first year, when the machines looked like "sling shots in the back of pickup trucks. "It was a local thing, good ol' boys having fun," she said, nursing a beer. "Now it's too commercial. It has to be homemade in your garage."