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blowhard Big Blowhards

What weighs 28,000 pounds, stretches 100 feet into the air, and shoots vegetables, frozen turkeys, and bowling balls? The biggest, baddest air gun of them all, dubbed Second Amendment. This is the machine that won first place in the 2006 World Championship Punkin Chunkin, as it did in 2002 and 2003.

Built by a team of arc-welding air gun builders headquartered in the exurbs of Detroit, Second Amendment is an enormous, truck-mounted breechloader, a howitzer capable of shooting a 10-pound pumpkin just shy of a mile. Last year, on the weekend following Halloween, Second Amendment and a couple dozen of its high-pressure cousins met in a harvested cornfield in the wilds of Delaware to show off their prowess at making stuff fly.

Punkin Chunkin (punkinchunkin.com) began officially 21 years earlier, when its three founders met informally to build hurling machines capable of flinging leftover Halloween pumpkins. Little by little, the hurlers improved their machines, and every year the pumpkins flew a bit farther. Things changed radically in 1995 when Trey Melson, one of the co-founders of the event, upped the ante.

abc Big Blowhards

Fig. A: Even the spectators come prepared for the competition. Fig. B: Fire and Ice is a double-barreled pumpkin cannon. Fig. C: An entrant in the youth air cannon division, Soldier Too was built by a son of one of the founders.

Jaws dropped and eyes widened when he hauled Universal Soldier to the firing line. The first truly giant pumpkin-shooting air cannon, Universal Soldier ushered in a new era in hurling. Now there are more than two dozen monster air cannons, all capable of shooting projectiles more than 2,000 feet. And a couple have even fired 5,000 feet.

Shooting with Air

The pumpkin guns of Delaware are simply the latest incarnation of machines capable of shooting things using air power, which is truly an ancient concept. Simple blowguns were used by prehistoric hunters to bring down small game. There are many references to breath-powered shooters by classical Roman and Greek historians. But mechanical (that is non-lung-powered) machines have a more recent history.

The oldest existing air gun is in the collection of the Livrustkammaren Museum in Stockholm, Sweden. The museum dates the device to around 1580 A.D. Air gun refinement occurred continually during the following 200 years. By the year 1800, air guns had developed to the point where they were likely more accurate and more powerful than contemporary black powder weapons of similar size.

For those who could afford them, air guns offered definite advantages: they were quiet and didn’t produce target-obscuring smoke. But the main perk was that they could be fired rapidly — several times a minute, which was far quicker than the load, tamp, and fire procedure required of muskets. By comparison with smooth-bore, muzzle-loading muskets, air guns were veritable machine guns.

One of the most historically important American weapons was the air rifle carried by Meriwether Lewis during the Lewis and Clark expedition of 1803–1806. The actual gun (there is some controversy regarding its exact patrimony) may reside in the Virginia Military Institute’s (VMI) museum near the stuffed remains of Little Sorrel, Stonewall Jackson’s Confederate warhorse. VMI’s .31 caliber, flintlock-style, 900 pounds-per-square-inch pneumatic rifle was crafted by expert clockmaker Isaiah Lukens in Philadelphia.

When fired, the Lukens rifle makes a weird, loud, whooshing sound instead of a bang. But it’s powerful; it could easily take down a full-grown deer. According to the records kept by the Corps of Discovery, the air gun did its job well, being effective for hunting game and impressing enemies.

Air gun popularity waxed and waned throughout the next 200 years. In the late 19th century, England was swept by the “air cane” craze. Although an air cane appeared to be but a simple walking stick, inside it was everything needed to shoot a bullet with enough stopping power to take down a large attacker. Truly, the air cane was a dangerous weapon and an impressive means of self-defense for the security-minded Victorian Englishman.

In 1950s America, air guns were again peaking in popularity. As anybody who has ever seen the movie A Christmas Story knows, Ralphie Parker, and most boys like him growing up in the 50s, longed for a Red Ryder BB gun, or as Ralphie put it, “the Holy Grail of Christmas gifts.”

Today, interest in air gunnery is peaking again, its health evidenced by a strong interest in airsoft guns, air-powered spud cannons, and — on the elephantine end of things — pumpkin guns.

Punkin Chunkin

At the 2006 Punkin Chunkin, held near Millsboro, Del., the long-standing distance records for pumpkin throwing came under serious pressure.

The current hot button in pumpkin chucking is breaking the mile barrier. A mile is a really long way to throw anything. Throwing a somewhat-fragile ten-pound pumpkin 10–12 city blocks is a task that requires simultaneous application of great power and extreme delicacy. Sure, tossing a cannonball such a distance might be small potatoes for a military cannon powered by 30 pounds of explosive cordite, but for the homemade air guns on the firing line, it’s a stretch goal. Still, the people who compete here are clever and hardworking, and many of them seem to think they have a shot at the mile benchmark.

Currently, the state of the art in pumpkin hurling technology leaves the gun teams only a few hundred feet short of the magic mile mark. The 20,000-plus people attending the Punkin Chunkin love to watch the big cannons at work, for there’s something undeniably interesting about a mile-shooting pumpkin gun made, for the most part, by regular Joes working in their garages and driveways.

Each gun is designed differently, and each has its own personality. Big 10-Inch is an engineer-designed gun that hides its top-secret workings behind an opaque covering. There are long, skinny cannons encased in spidery metal superstructures, such as Skybuster, Fire and Ice, and Please Release Me. There is the Harley-vibed Bad Hair Day, a gun crewed by a leather-clad female team, and the venerable and patriotically themed Old Glory, a former world record-holder that is always a favorite with the local crowd.

The technology behind these big blasters is not complicated, more a matter of scale than of high-tech engineering. The barrel of an air cannon is simply a large-diameter steel or aluminum pipe, usually scrounged from an industrial or agricultural scrap heap. The door and pumpkin-holding area inside the cannon are called the breech. Often this is simply a bolt-on steel plate near the bottom of the barrel and a grate on which to hold the pumpkin in place.

The basic principle of air- or gas-powered cannon operation is simple: rapidly introduce a powerful push of high-pressure gas from nearby storage tanks into the breech of the cannon and, in doing so, push the pumpkin out of the barrel as forcefully as possible.

Valves control the release of the high-pressure air. The valve design is critical: a too-small valve, even if it opens very quickly, will retard the accumulation of pressure inside the gun and hinder performance. A big valve that opens too slowly will do the same. The most resourceful builders incorporate a big, fast-acting group of valves that instantly open the floodgate of high-pressure air or gas.

This competition isn’t about money or trophies or even the teardrop-shaped mass of gooey pumpkin flesh a mile away in the middle of a Delaware farmer’s field. It’s about pride. It’s about being the best, about setting a goal and achieving it. When told of the time and money invested in making these guns, a lot of people simply smile and shake their heads. But not real makers. Real makers understand.

See the Maker File video episodes from Punkin Chunkin: makezine.com/blog/archive/the_maker_file.

William Gurstelle

William Gurstelle

William Gurstelle is a contributing editor of MAKE. The new and improved edition of his book Backyard Ballistics is out now.


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