Hi, I'm new here, but anyways, I was wondering, would it be feasible to make a combustion airsoft gun? I would use a Bic pentube for a barrel (airsoft pellets fit perfectly inside), and a clear, thick walled water bottle for the combustion chamber. (I like to see the flame)

Or, I would possibly use a beef stock container for the combustion.
Ok, well i know it would be possible, but do you have any extra suggestions for me? (Fuel, Ignition, ETC.)