Iv been thinking of an idea and want to know if any one has actually tried it yet. Take a potato cannon with some power and make a HE round using a piece of PVC pipe as a mold for something like plaster of paris let it dry sand it smooth and you could A. Use the combustion from the gun to light a fuse in the back or B. Make a simple impact type firing device incorporated into the mold. Fill with some HE and fire remotely (Stun gun, speaker wire and sandbags). The best tool for this would probley be a dremel.

Ill tell you right now, Plan b has some huge problems, mostly the force of the impact apon ignition. I have found that most impact devices go off in the barrel. Plan a only works if the fuse lights when fired, otherwise you just handed "the enemy" a usable bomb.

What I have used that worked well basicly was a pipe w/ rocket engines and CO2 bombs that i lite the fuse on the CO2 first then fired the engine launching the CO2 bomb about 75ft until it hit a tree and blew up. This isnt that accurate and u then have a "signal flare" flying uncontrollably into the sky. But if you just need to hurl a HE device 20-30ft at a large stationary target it could be useful.

SWIM once tried firing a CO2 cannister full of AP out of an aircannon. It hit a tree and bounced off without exploding, then evaded all of SWIM and his friends' attempts to find it again. SWIM put the failure to explode down to the fact that the steel case of the CO2 cannister would have protected the actual AP crystals from being crushed.

SWIM never tried a similar stunt again, having realised it was a bad idea. However, who knows, SWIM may eventually get around to making a proper explosive round for his aircannon, using a rifle primer as the impact detonator.

Plan B isn't that hard to do without worry of setback, at a minimum I would use 2 safety devices. A spring of the proper tension would prevent detonation unless the round slams into an object of choice. Also you could incorporate a lanyard to be pulled upon exiting the cannon, the lanyard would provide a physical block between the firing pin and primer. Its not that hard with a dremel and a material thats easy to work with.

With plan A it would be best to spray the back of the round and fuse with starter spray, just to make sure it lights.

Once upon a time, many moons ago I owned a 25mm spud gun, 50mm chamber. I made some smoke rounds which were designed with short amount of exposed fuse projecting about 2cm - 3cm out their rear to take fire from the exploding gasses and transmit it through a layer of protection wadding to the smoke mix before igniting the charge. The fuse failed to ignite when the round was loaded in the breech and fired. The fuse was easily lit however, by the flame if held across the barrell while firing a chamber of fuel without projectile. The fuse if loaded into the breech and fired out on it's own without any other projectile would also light. The gas expansion was pushing these rounds out of the barrell before the fuse could be heated sufficiently to ignite. Straight air exists in the barrell behing the round in adition to the fuel air mixture in the chamber and this was buffering the fuse and projectile. To fix this problem, I can think of two measures that should be taken. Neither I have tried. I dont have a spud gun any longer.

I should mention that the fuse used was of the type created as follows. Make concentrated, but not saturated, very hot solution of KNO3 , about 20% solution, and dip in 1 inch by many inch strips of newspaper and allow to dry. Roll into cylinder. Burn rate typically in the order of 1cm per second.

The first step is to prime the fuse with a more easily ignited mixture, like stars are primed before loading into fireworks. A KCLO3 based mixture would be ideal, or BP would be fine. Dextrin binder for the primer composition is typical for many star compositions. This type of modification requires the fuse is already exposed to hot gasses under the original design. I am not sure it was. The second measure is to increase dramatically the length of fuse used, so that it is deep in the combustion chamber when the gasses ignite. Quick match with an exposed primed end could be used to take fire and transmit it quickly to the round, which would also be comprised of a delay fuse.

Quick match is wind resistant as it has a paper shield for the burning bp as part of its construction, it also burns fast enough to get fire to the main body of the round quickly. Once fire reaches this point, any device could be used with a suitable amount of delay fuse.

Cyclonite - any suggestions on how to use your lanyard idea without dramatically affecting accuracy? It would seem to me that the force required to remove the safety would act on the projectile, in an unpredictable way. The primer and safety would have to be at the front of the projectile - so when the lanyard reached its length and pulls the safety - wouldnt the projectile tumble?
Or am I missing something?

It would affect it, but this isn't a firearm....the cannons aren't really accurate to begin with. You're just looking to more or less lob the round into a larger target or hit an area target. I used to go up on this large hill at night that overlooked the freeway and a car dealer. I used to shoot lots of rounds into the car lot and attempt to hit the dealership sign...good times.

You could also hook it up to the back of the projo....personally i wouldn't even use it.....I would just aim and fire from a distance if I were to use AP as a filler to keep it real simple

You could also insert an ematch into the fuse, spray in your fuel, close it up, and then use the ematch to ignite the fuse, which will also ignite the fuel inside.

It could be done pretty simply, and any pyro worth his salt at least has a basic ignition control panel. Using this method of ignition for the charge, you could use pretty much anything as your charge, so long as it isn't sensitive to shock.

Well, I've thought about this same thing on more than one occasion...Instead of making a mold with the pvc pipe, just use the pipe. To make it fit the inside of the barrel you can make a sabot for it using that expanding foam you can get at the hardware store for sealing around air ducts and what not. To improve accuracy of the gun you can use rifled pvc. It's available at http://www.spudtech.com . For ignition, I would go with an impact trigger using shotshell primers.

For the projectile just use sch40, the normal white pvc, thats 1 1/2" in diameter for the body/endcaps. Don't just glue the endcaps on, they'll just get pushed off by any explosion inside and the round will pretty much be a dud. Just put a screw or two through the endcap and pipe to hold them on. It's pvc anyways, not an ideal container for an explosive round, but it'll do since the round can't be all that heavy. For the ignition you could drill a hole in one of the endcaps and glue a primer in the hole. To make a "hammer" for the primer you could use a cutoff nail through half of a wooden ball glued/screwed onto the round. On the flat side of the half-ball just drill a large enough hole to go around the primer so it will fit flush against the pipe, but not all the way through of course leaving a half inch or so out on the front of the ball. Since the nail is cut off, just drill a hole a tad smaller than the nail and hammer the nail through the hole till it is a quarter inch away from the primer and glue it on...

For the sabot just get another pipe or some sort of container a little bit bigger than the inside of the barrel for the mold. Make sure it has -smooth- walls. Put a pipe the same size of the round in the middle of the container and fill up around the pipe with the expanding foam and let it dry. Then push the sabot out and cut it in half or quarters.

Since you are using a sabot you could put mini-fins on the round and just place the fins in the cuts of the sabot. See if it'd help with accuracy/flying properly.

For a payload you could use normal bp or pyrodex...To keep it real light you could use homemade nitrocellulose. If you really wanted to go with a HE round, you gotta go read or something...I'm not of much use with HE's...If MEKP is fine in a pvc container you could use MEKP sesitized(sp?) AN. You'd have to have another small explosive inside to do that. Or I would think so to set it off, though shotshell primers let off a pretty good crack when you hit them with a hammer in open air. I don't know if the shock from being shot out of a spud gun would set it off or not. As I said though, I don't know much about HE, shouldn't even really suggest any way to use them, just an idea though...

Oh, the wooden spheres can be had at any craft store, and in different sizes so it'll be the same diameter as the pipe.

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