A friend and I are going to try to build a few trip mines this weekend in preparation for our scenario next weekend. For the 'explosion', we're using a 12g CO2 cartridge, and are planning on having it spring loaded, with a pin attached to a trip wire. When the wire is pulled, the pin is pulled, releasing the spring to drive the cartridge into a screw, hopefully bursting the tip, and expelling the gas through a paint chamber. I'm very sure that I'm not the first one to try this, and I'm also very sure that many have tried before me and failed. I can forsee a few outcomes, and in descending order of probability, they are:

1) Spring is not strong enough, and doesn't burst the cartridge.
2) Spring is too strong, and pinches the pin in place, turning my trip mine into a literal trip mine.
3) ______ <- Fill in the blank
4) Success.

Any experiences not already posted that you more experienced folks can give me?

yea, be very very careful and make sure if its supposed to "explode" that its done in a same manor and there are no fragments or shrapnel produced...

start with light springs and work from there always do less then more (IE start with the weakest set up possible that most likely wont work and gradually [one piece at a time] make it better)

make a safety switch so if it is accidentally triggered it wont go off (think while transporting it in a car or something) also make it so the cartridge can be removed for storage (again think of the above situation....you in a car...)

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Update: We have a beautiful PVC mine, that should work, but we're having a small problem. We're using the firing mechanism from an old pump gun, inverted, and installed to drive a CO2 cartridge down onto a sharpened screw at the bottom of the container when the trigger is pulled via the trip wire. The only problem is, the spring is too strong, and when fired, it keeps the cartridge pressed down on the screw, effectively plugging the hole the screw makes... We're going to try to use lighter springs, without going too light, to the point that it doesn't puncture the cartridge. Other than that, we have nozzles designed to direct the paint toward the enemy, and when we fill the mine with paint, and deploy it, it should work perfectly... :knock on wood:

Update #2: Great success! We have made a working prototype that we'll be deploying tomorrow during our scenario game. We test fired with only water for the first attempt, and got a glorious burst spraying about 12' high, and 15' in range, that would have completely covered anyone standing in front of it.

We changed the trigger mechanism out for a cotter pin setup, and it works great. A good enough force required to remove the pin that should eliminate misfires when setting up the mine, but not so much as to trip over people walking/running. The guy helping me took it home tonight to finish painting it and fine tuning it, then we'll have a completed part for tomorrow.

I'll try to take a few pictures to post on here if I can.

Dang! Keep us posted mate!

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Here she is. This is made from 4" diameter PVC, and for the first batch of them, we'll be using 3" to try to make them smaller.

I can report that the mine actually works too. I didn't place it in the best spot, and no enemies came through where I buried it, but a teammate who joined late (who I may have forgotten to tell where it was) certainly found it... He wasn't dripping with paint, but he certainly had a good bit on him, and he knew he was hit, which is all that matters really. We took a video of it that I think my friend is going to post online. I'll try to link it when it shows up.

coool, can't wait to see it....

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i wanna see a vdeo

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I learn quick and i kill quicker

So we don't really have a good video of it working yet. We still haven't perfected the firing mechanism, so I was demonstrating it to our group by pulling the pin with pliers. As you'll see, the blast was more than I was expecting, and the mine blew onto its side and all over me...

YouTube - This Is what happens when you mess with paint