# Punkin Chunkin: what muzzle velocity? **URL:** \ **Category:** Factual Questions\ **Created:** [November 26, 2011, 5:00am UTC](https://boards.straightdope.com/t/punkin-chunkin-what-muzzle-velocity/604123 "2011-11-26T05:00:45Z")\ **Posts on this page:** 16\ **Page:** 2
**Author:** ![Tastes\_of\_Chocolate](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tastes_of_chocolate/32/3232_2.png) [@Tastes\_of\_Chocolate](https://boards.straightdope.com/u/Tastes_of_Chocolate)\ **Post date:** [November 29, 2011, 8:01pm UTC](https://boards.straightdope.com/t/punkin-chunkin-what-muzzle-velocity/604123/21 "2011-11-29T20:01:06Z")
My SO and I were discussing this this weekend. Idea 1 - Railgun - put the pumpkin on a cart and excelerate cart + pumpkin. Idea 2 - possible improvement to the air cannons. Have 2 gas releases. First is a smaller release of a heavy gas. Get the pumpkin started, and the heavier gas, being larger molecules, might leak less around the pumpkin and act as sort of a plug. Then hit it with the large volume of air. As for the ideas of growing pumpkins in boxes/forms. Not allowed, per the rules. You can breed the pumpkins to a state you like better, but you can’t form them. ---
**Author:** ![Snarky\_Kong](https://avatars.discourse-cdn.com/v4/letter/s/a183cd/32.png) [@Snarky\_Kong](https://boards.straightdope.com/u/Snarky_Kong)\ **Post date:** [November 29, 2011, 8:25pm UTC](https://boards.straightdope.com/t/punkin-chunkin-what-muzzle-velocity/604123/22 "2011-11-29T20:25:26Z")
> [@Tastes\_of\_Chocolate](#): > > My SO and I were discussing this this weekend. > > Idea 1 - Railgun - put the pumpkin on a cart and excelerate cart + pumpkin. > > Idea 2 - possible improvement to the air cannons. Have 2 gas releases. First is a smaller release of a heavy gas. Get the pumpkin started, and the heavier gas, being larger molecules, might leak less around the pumpkin and act as sort of a plug. Then hit it with the large volume of air. > > As for the ideas of growing pumpkins in boxes/forms. Not allowed, per the rules. You can breed the pumpkins to a state you like better, but you can’t form them. I was under the impression that sabots were not allowed. Also, it wouldn’t matter because the air resistance would tear the pumpkin apart once it left the cart. Sturdier pumpkins are needed. Can they do what the largest pumpkin people do and cross-breed them with squash? They’re not hollow if it’s done right, apparently. ---
**Author:** ![Enright3](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/enright3/32/2897_2.png) [@Enright3](https://boards.straightdope.com/u/Enright3)\ **Post date:** [November 29, 2011, 8:29pm UTC](https://boards.straightdope.com/t/punkin-chunkin-what-muzzle-velocity/604123/23 "2011-11-29T20:29:55Z")
> [@Tastes\_of\_Chocolate](#): > > My SO and I were discussing this this weekend. > > Idea 1 - Railgun - put the pumpkin on a cart and excelerate cart + pumpkin. > > Idea 2 - possible improvement to the air cannons. Have 2 gas releases. First is a smaller release of a heavy gas. Get the pumpkin started, and the heavier gas, being larger molecules, might leak less around the pumpkin and act as sort of a plug. Then hit it with the large volume of air. > > As for the ideas of growing pumpkins in boxes/forms. Not allowed, per the rules. You can breed the pumpkins to a state you like better, but you can’t form them. I think the air cannons have to use compressed air. I tried (but failed) to find a story about one of the air cannons being disqualified for using some type of gas (Helium?). ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [November 29, 2011, 9:59pm UTC](https://boards.straightdope.com/t/punkin-chunkin-what-muzzle-velocity/604123/24 "2011-11-29T21:59:30Z")
Using helium for something like this would be extremely expensive, and probably wouldn’t give any benefit. Carbon dioxide is more likely. ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [November 29, 2011, 10:31pm UTC](https://boards.straightdope.com/t/punkin-chunkin-what-muzzle-velocity/604123/25 "2011-11-29T22:31:34Z")
> [@RearEchelon](#): > > _This_ … How is that anything but a modern siege engine? Launching heavy, dense projectiles that aren’t self-propelled on a ballistic trajectory toward a target from outside the target’s own attack range? Sounds like a siege to me. … By this definition ordinary modern artillery cannon qualify. Heavy? Check. Dense? Check. Non-self-propelled? Check. The point of these competitions to date IMO is to stick with power sources known in ancient times: gravity, springs of some nature cocked by human or animal power only, etc. Once you allow more modern power sources then explosives, air compressors powered by gasoline engines, rail guns, warp drives, … it’s all fair game. I think in another couple of years of continued air cannon development they’re gonna hit the limit of what the gourds can be grown to withstand. Pie-ing 8 of 10shots will not be entertaining. Then like any sport hitting a rule barrier, they’ll need to decide what rule changes will keep the game entertaining enough to keep the sponsors happy. One approach is then to limit air tank capacity & pressure or something similar to weaken the cannons. The real competition will then be engineering to extract max range from the limited power source. Another approach would be to go for max performance & switch away from gourds to carefully machined uniform cylindrical blocks of oak or something. Range would go way up and while they’re no longer chunkin’ punkins as such, they’re still using home-brew air cannons to fling inert hunks-o-stuff a very long way. That might still be a crowd pleaser even without the risk of pie. ---
**Author:** ![Terr](https://avatars.discourse-cdn.com/v4/letter/t/839c29/32.png) [@Terr](https://boards.straightdope.com/u/Terr)\ **Post date:** [November 29, 2011, 10:49pm UTC](https://boards.straightdope.com/t/punkin-chunkin-what-muzzle-velocity/604123/26 "2011-11-29T22:49:15Z")
> [@LSLGuy](#): > > The point of these competitions to date IMO is to stick with power sources known in ancient times: gravity, springs of some nature cocked by human or animal power only, etc. Once you allow more modern power sources then explosives, air compressors powered by gasoline engines, rail guns, warp drives, … it’s all fair game. Right now, the trebuchets/catapults/torsion devices in the Punkin Chunkin competition are wound by all kinds of mechanical/modern methods, and the catapults’ energy storing device can be (IIRC) pneumatic. > [@](#): > > Another approach would be to go for max performance & switch away from gourds to carefully machined uniform cylindrical blocks of oak or something. Range would go way up and while they’re no longer chunkin’ punkins as such, they’re still using home-brew air cannons to fling inert hunks-o-stuff a very long way. That might still be a crowd pleaser even without the risk of pie. I believe the towns around the competition would be in danger then. ---
**Author:** ![Tastes\_of\_Chocolate](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tastes_of_chocolate/32/3232_2.png) [@Tastes\_of\_Chocolate](https://boards.straightdope.com/u/Tastes_of_Chocolate)\ **Post date:** [November 29, 2011, 11:59pm UTC](https://boards.straightdope.com/t/punkin-chunkin-what-muzzle-velocity/604123/27 "2011-11-29T23:59:47Z")
> [@Snarky\_Kong](#): > > I was under the impression that sabots were not allowed. Also, it wouldn’t matter because the air resistance would tear the pumpkin apart once it left the cart. Sturdier pumpkins are needed. Can they do what the largest pumpkin people do and cross-breed them with squash? They’re not hollow if it’s done right, apparently. The official rules allow the judges to rule that something isn’t a pumpkin and is therefore disqualified. [Rules.](http://www.punkinchunkin.com/machine-rules) > [@](#): > > 6.WCPCA accepted pumpkin types or species are as followed: > 1.Traditional orange, white, or ornamental pumpkins are allowed. > 2.If the WCPCA determines a fruit does not qualify as a pumpkin, proof from the seed manufacturer or commercial grower proving otherwise may be used to overturn this ruling. > 3.Any breed of pumpkin can be banned if deemed harmful to the owner’s use of the field. > 4.Refer to list of pumpkin varieties at [www.allaboutpumpkins.com](http://www.allaboutpumpkins.com) for some accepted pumpkins. FYI - 338 days, 13 hours until the next contest. Start building now. ---
**Author:** ![chacoguy](https://avatars.discourse-cdn.com/v4/letter/c/50afbb/32.png) [@chacoguy](https://boards.straightdope.com/u/chacoguy)\ **Post date:** [November 30, 2011, 1:27am UTC](https://boards.straightdope.com/t/punkin-chunkin-what-muzzle-velocity/604123/28 "2011-11-30T01:27:58Z")
> [@Enright3](#): > > I wouldn’t go so far as to say that he’s over a thousand feet short. Yes, Big 10 Inch did shoot one that far; but that was in Moab Utah under the best conditions for a long distance shot. I’m not ragging on the guy. That shot took place less than five miles of where I am now and I thought I’d share. ---
**Author:** ![Colophon](https://avatars.discourse-cdn.com/v4/letter/c/f05b48/32.png) [@Colophon](https://boards.straightdope.com/u/Colophon)\ **Post date:** [November 30, 2011, 4:20pm UTC](https://boards.straightdope.com/t/punkin-chunkin-what-muzzle-velocity/604123/29 "2011-11-30T16:20:44Z")
I had never heard of this pastime. I am suitably awed. ---
**Author:** ![TubaDiva](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tubadiva/32/507_2.png) [@TubaDiva](https://boards.straightdope.com/u/TubaDiva)\ **Post date:** [November 30, 2011, 4:29pm UTC](https://boards.straightdope.com/t/punkin-chunkin-what-muzzle-velocity/604123/30 "2011-11-30T16:29:41Z")
> [@Scuba\_Ben](#): > > Clearly we need to put together a Doper team, starting by growing pumpkins in containers to give the proper aerodynamic shape. Plus pie recipes. And we need to determine the caliber of pumpkin that would take out a T-rex. ---
**Author:** ![Irishman](https://avatars.discourse-cdn.com/v4/letter/i/b487fb/32.png) [@Irishman](https://boards.straightdope.com/u/Irishman)\ **Post date:** [November 30, 2011, 6:31pm UTC](https://boards.straightdope.com/t/punkin-chunkin-what-muzzle-velocity/604123/31 "2011-11-30T18:31:10Z")
> [@chacoguy](#): > > I’m not ragging on the guy. That shot took place less than five miles of where I am now and I thought I’d share. You’re just scared you’re the next target. 😉 ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [November 30, 2011, 10:47pm UTC](https://boards.straightdope.com/t/punkin-chunkin-what-muzzle-velocity/604123/32 "2011-11-30T22:47:09Z")
> [@](#): > > Is it the max air-speed that causes the pumpkin to pie, or the acceleration (G-force) ? Supersonic speeds by themselves would be sufficient to pie a pumpkin, though I don’t think subsonic speeds would. Subsonic, I imagine it would just be the acceleration. ---
**Author:** ![NoCoolUserName](https://avatars.discourse-cdn.com/v4/letter/n/5fc32e/32.png) [@NoCoolUserName](https://boards.straightdope.com/u/NoCoolUserName)\ **Post date:** [November 30, 2011, 11:01pm UTC](https://boards.straightdope.com/t/punkin-chunkin-what-muzzle-velocity/604123/33 "2011-11-30T23:01:03Z")
> [@ruh-roh](#): > > Or how about a really large trebuchet throwing a torsion launcher that is loaded up with an aircannon (on a bump on a log in a hole in the bottom of the sea) ? 🙂 And the green grass grew all around? ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [December 1, 2011, 4:22pm UTC](https://boards.straightdope.com/t/punkin-chunkin-what-muzzle-velocity/604123/34 "2011-12-01T16:22:40Z")
> [@Colophon](#): > > I had never heard of this pastime. I am suitably awed. Be sure to check out the links in the OP. You may be able to find some of the TV shows online. ---
**Author:** ![NDCompuGeek](https://avatars.discourse-cdn.com/v4/letter/n/b4bc9f/32.png) [@NDCompuGeek](https://boards.straightdope.com/u/NDCompuGeek)\ **Post date:** [December 2, 2011, 9:58am UTC](https://boards.straightdope.com/t/punkin-chunkin-what-muzzle-velocity/604123/35 "2011-12-02T09:58:43Z")
> [@ruh-roh](#): > > Is it the max air-speed that causes the pumpkin to pie, or the acceleration (G-force) ? If the latter, then maybe something similar to the proposed two-stage gas system to reduce the acceleration but get the same final muzzle velocity. Would need a longer barrel though. > > If it is the max air-speed that causes the pie, then could you nest two pumpkins? When the outer one is torn apart by the air friction, then the inner one could continue. It would be smaller, so not as much air friction, although also being lighter it would not have as much inertia. > > Or how about a really large trebuchet throwing a torsion launcher that is loaded up with an aircannon (on a bump on a log in a hole in the bottom of the sea) ? 🙂 Man, I must be getting tired. I skimmed this post and in my mind I said “What is the aerial velocity of an unladen swallow?” complete with sound effects and in the correct voice. must get some sleep … ---
**Author:** ![Oslo\_Ostragoth](https://avatars.discourse-cdn.com/v4/letter/o/a9a28c/32.png) [@Oslo\_Ostragoth](https://boards.straightdope.com/u/Oslo_Ostragoth)\ **Post date:** [December 3, 2011, 3:01am UTC](https://boards.straightdope.com/t/punkin-chunkin-what-muzzle-velocity/604123/36 "2011-12-03T03:01:25Z")
> [@LSLGuy](#): > > Be sure to check out the links in the OP. You may be able to find some of the TV shows online. Multiple clips [here](http://science.discovery.com/videos/punkin-chunkin-videos/) and on YouTube. [Previous page](https://boards.straightdope.com/t/punkin-chunkin-what-muzzle-velocity/604123.md?page=1)