Science

This Punkin Chunkin Team Plans to Shoot a Pumpkin a Mile With a Massive Gun

We talk with Steve Pierce of American Chunker about the testing the limits of gourd displacement.

Steve Pierce

Every now and then, Steve Pierce and his teammates get together to shoot pumpkins as far as they can using a gigantic air cannon they’ve affectionately named American Chunker. It’s a hobby, sure, but also training for the niche pseudo-sport dubbed Punkin Chunkin, which challenges teams to shoot pumpkins over long distances. This peculiar extracurricular has grown in popularity ever since a competition aired on Discovery a few years back. No one takes the activity itself seriously, but damn if these guys don’t know about their machines.

Inverse spoke to Pierce about what it takes to be the best chunker around.

The American Chunker air cannon.

Steve Pierce

How do you explain Punkin Chunkin to people unfamiliar with it?

I usually say that Punkin Chunkin started about 25 years ago with guys getting together and saying, ‘I think I can throw one further than you.’ They made a catapult and somebody shot a pumpkin like 120 ft. or something like that. Then people started doing it year after year.

What they have now is catapults and trebuchets and centrifugal units. They’ve got human-powered units all the way up to the big guns, the air guns themselves. Overtime it evolved into bigger and bigger events.

How did you get involved?

I have a friend whose brothers were on the team. One Thanksgiving we watched the Punkin Chunkin and he said, ‘I’m a member of this team.’ The very next year I went down to see what it was all about and fell in love with it and asked to join. I even had to send in my resume.

You have a day job, but how would you categorize this? Very extreme hobby?

It sure is.

It seems like it would be a very costly hobby, no?

No, not really. Team leader Brian LaBrie financed the building of the machine. He owns it, and he pretty much finances most of what goes on with it.

How much did the American Chunker cost to make?

I’d say it cost over $100,000. I don’t know the exact figure.

Did the makeup of the machine evolve over time?

No, Brian made the model in 2009 or 2010, and pretty much stayed with the same gun. However, we did tweak this or that. So you know, secret little things to try to make it so it will go further. Basically it’s the same gun, but there may have been a couple twists and turns of screws and what not.

And it basically folds up, right? How big is it compacted?

20 feet, something like that. It’s about 25 ft long or so and weighs about 11 tons. We store the barrels on a rack that’s attached to the trailer. The barrel breaks apart into three pieces so we store those three 20 ft lengths on the unit itself. It travels with all of it pretty much self-contained.

What do you actually have to do during competitions?

During a competition we have a three minute window. Basically we power up and somebody mans the compressor to power up the gun, someone is checking the pressure, someone puts the pumpkin in the breach and closes it up and makes sure the valves are shut correctly and everything’s tied down. Then we wait for the opportune time that we think maybe the wind’s going our way when we’re on the clock. But hopefully we can tweak it and elevate it and lower it to a certain degree and then fire it when we think it’s the best opportunity to do so.

Team American Chunker.

Steve Pierce

How much compressed air goes into an ideal shot?

A lot. On average, air cannons in general can be anywhere from 150 lbs to 700 lbs. We are somewhere in the middle of there, but I’m not going to tell you.

We’ve said it’s a hobby, but does anyone on the team have a science background?

Yes. Basically, the shooting part isn’t really the hard part. We’ve got hydraulics engineers, civil engineers, computer engineers, mechanical engineers all working together. I happen to be one of the few who are not. I’m an English major, actually. So we’ve got somebody who puts together a program to figure out the best ballistics model to use given the size and shape of the pumpkin.

I’m the member of the “PHD,” Pumpkin Harvesting Department. We actually solicit farmers to grow for us. So we provide the seeds for them and they grow and then we’ll go and spend hours looking for the perfect pumpkin.

What is the ideal pumpkin?

It’s a special type of pumpkin: the La Estrella pumpkin. It’s a hybrid, actually. It’s got a thick wall and a small seed cavity, and it pretty much resembles a cannonball rather than the regular field pumpkin you use for jack-o-lanterns.

Is there any other sport you can compare Punkin Chunkin to? The big community surrounding the event makes it seem maybe like NASCAR or something like that.

I would agree. I would compare it to rodeos as well. It’s kind of a rodeo atmosphere. It’s clean fun, so to speak. You can bring your family.

…A rodeo with engineers…

The handful of engineers and professionals and do-it-yourselfers involved in it are all very clever folks. It’s kind of a geeky hands-on thing. We’ve got the scientists, we’ve also got the guys who know how to weld, who know how to turn a screw, turn a bolt, and not afraid to get their knuckles banged either. So it’s an interesting combination of people. We’ve got dentists and teachers too — you name it.

The big event was most recently on TV on Discovery. Do you like that wide exposure or would you rather it remain a close-knit community-based hobby?

We love the exposure. We’d love to make it more popular and make more people aware of it for sure. The difficulty is the last two years were cancelled: one, for lack of a place to do it and this year they claimed that no insurance company would underwrite it.

Do you basically use these events as practice? Is there a range?

We do have a place that we practice. It’s very hard to practice full-length shots because you need a mile. We managed to find a place, and I don’t have permission to give the name, but there’s a farm in the area which is terrific because it’s all just grass. It’s completely clear so we can see where the pumpkin falls. It’s 7,000 feet of free area.

Otherwise we’ve done things with a radar gun or high speed video, and measured by calculating the speed. So it’s a combination of things. We’ve got a company called CADD Edge that runs a physics program called Solidworks, and we program in whatever we want and it’ll sort of predict what happens with the pumpkin.

What’s the range of a good shot? Also, what’s the name for the actual act of shooting the pumpkin?

We call it “chunkin,” which is the throw so to speak. If the pumpkin breaks into pieces, we call that “pie” or “pie-ing,” which is not good, of course.

We won a world competition record in 2013 with 4,694 ft. Nobody’s beat that yet. Anything over 4,000 feet is really good. Anything below that won’t be good competition.

Is there a distance goal American Chunker wants to get?

It’s the mile. 5,280 feet. The physics regarding that is tough — the faster the pumpkin goes, the closer to the speed of sound it gets, the harder it pushes against the atmosphere. That mile is quite an elusive distance.

We want to achieve the mile. We’d also love to have a legacy. We really want to be number one as much as we can.