Create these targets AT YOUR OWN RISK. Materials include compressed air, flammable liquids, and fire. Dangerous by themselves and downright stupid to put all together. I ASSUME NO RESPONSIBILITY FOR WHAT YOU DO.
Now, with all that unpleasantness out of the way, let's have some fun.
Step 1: Materials
Plastic bottle with lid (Ive found that PLASTIC beer bottles work well)
Pneumatic valve (I used an all-metal version from truck wheels)
Pellet gun and pellets (pointed for best results)
Lighter fluid or tiki torch fluid
Compressor adaptor that fits your valve
small oil lamp (im not going to go over how to make this because there are a million different ways to make one that will work perfectly,
all it requires is some scrap metal and a piece of cotton fabric, see picture)
Lighter, matches, etc.
Tools to assemble it all (a wrench)
(again, I'm sorry the pictures are sideways)
Step 2: Assembly
The magic behind the explosion is compressed air in the bottle and to achieve that we need to put a valve in the lid of the bottle, like a bike tire. To do this simply drill a hole the size of your valve stem in the lid of the bottle and attacth it how you like to make it air-tight, mine had a nut and rubber washers.
And that's it. That's al the assembly required.
Step 3: How to Use
Step 4: Closing Thoughts
No fluid coming out with the air. Solution: Shoot lower or add more fluid.
Air blows out lamp. Solution: Use hotter-burning lamp oil, less psi, or move the lamp further away.
Bottle isn't punctured (this one was a pain) Solution, hollowpoint pellets or less psi.
If you don't want a fireball just don't add the fluid, instant decompression is still a pretty fun target.
Be safe, have fun, and happy shooting!