Designing a homemade Gun - Part 1
Disclaimer: This is purely for educational and self gratification purposes. I beg you not to misuse this information.
Things you need:
1.) Barrel - A hollow strong PVC pipe with a minimum of 8-10 mm thickness. 3 feet long. Make sure the pipe doesn't have a curvature else you will have lots of friction when the bullet goes off.
2.) Gas Chamber - A bigger hollow pipe which will be the place where the chemical reaction will take place to push out the bullet. The chamber pipe should be in such a way that the front can be sealed of with the barrel inserted into it and the rear ended which can be opened anytime to put in the fuel. Use heat to seal things when using plastic.
3.) A gas stove lighter or some device which will provide the ignition spark.
4.) Chemical composure - First we tried common flammable substance such as petrol, kerosene, vodka, ethanol. But none of them provided the explosion needed to fire a marble with a decent force. Finally we settled on butane, isopropanal. Just a few ml of the propellant, the marble almost went to a distance of 50-70 mts.
The base and casing done. Need to work on the enclosure and the paint job.
I will be uploading a video of the entire procedure soon and also the test rounds in the part-2.