Boom! The classic potato gun harnesses the combustion of flammable vapor. Show us your combustion spud gun and discuss fuels, ratios, safety, ignition systems, tools, and more.
Here's my new special zombie survival spudgun. It fires 20mm polypropylene projectiles with a steel penetrator. The barrel is 28mm inner diameter so the projectiles are with a little increased diameter at the one end. The fuel is in pre-loaded 2l coke bottles(two under my bed and 3 over the wardrobe) and is H2:N2O 1:1 or Methanol and N2O. The ignition is with two professional pyrotechnic ignitors powered by two AA alkaline batteries. The trigger is two well sanded copper plates with a plastic safety witch goes to the one side to disengage. The barrel is ported. Allowing the pressure to drop before the projectile leaves the barrel makes every shot ridiculously accurate. The gases pass trough steel wool witch cools them and adds a little sound suppressing effect. It may look a little ghetto but I'm on a budget here and the tape isn't holding anything critical. I couldn't make a video with it but here's a link with an equivelent gun (that one is a prototype with lighter piezo ignition, no glue used to hold the cut off bottle cap in the gun but still no fail of anykind)
currently I'm trying to make a zombie survival pneumatic, but I'm failing miserably cuz I'm not willing to spend any more then I spend on my combustions-7$ average
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Last edited by RamboNucke on Sat Mar 24, 2012 4:04 pm, edited 1 time in total.
What sort of performance are you getting? If I recall correctly the old standard for anti-zombie effectiveness was penetration of 2.5 inches of pine board, and those planks you're shooting at seem pretty thick...
hectmarr wrote:You have to make many weapons, because this field is long and short life
I trust my design more then I trust any button. About performance, I did a test. 6 layers of denim, 2 layers of rubber, one layer of 1/2" sticks, 4 layers of cardboard, few more layers left from testing of my knives. The steel penetrator went trough this and 1 inch in to the wood behind, and that's a pretty fat diameter. Now I'm thinking a way of making hollow point somehow.
In the context of stopping zombies and given that velocity is relatively low, isn't something like this a better idea as opposed to an expanding projectile?
hectmarr wrote:You have to make many weapons, because this field is long and short life
The cheapest of that kind of arrow tip costs more then two spudguns I don't mean hollow point with some hydroshock effect or something, but if the projectile can split in 3 or 4 after it penetrates the target. Here's my latest test. The projectile was with AA battery instead of steel.
RamboNucke wrote:The cheapest of that kind of arrow tip costs more then two spudguns
Yeah, if you buy them. With a bit of creativity though...
Why not multiple projectiles in a shotgun sense though? You're shooting at close range, so it will still be a tight group.
Spherical projectiles are not ideal though, especially from something less powerful than a shotgun, so perhaps something like this would be more useful.
Somewhere between buckshot and flechettes.
hectmarr wrote:You have to make many weapons, because this field is long and short life
That's a fair point, a unitary slug will tend to penetrate more than multiple projectiles. You could always think up some creative filling for your projectiles but any such discussion is not appropriate for the forum.
hectmarr wrote:You have to make many weapons, because this field is long and short life
Seems you were in a bit of a hurry to get out of there
The fact that the wrapper snapped off really shows how much that bottle is expanding... a couple wraps if tape would probably be a good idea.
Other than that, nice recoil and combustion flash.
Shooting such a device in the open areas, between the blocks and the streets is a complete idiotism. I'm in the city mothers with babys are walking around here. Under the bridge is the only somewhat safe test site. There are very few people coming to see what happened after each shot and my friends tell me it's not that loud. I wish I could achieve that firepower with something cute and short (and cheap )
and the tape isn't holding anything critical. I couldn't make a video with it but here's a link with an equivelent gun (that one is a prototype with lighter piezo ignition, no glue used to hold the cut off bottle cap in the gun 
but still no fail of anykind) 
