I have read that propane has approximately the same pound for pound explosive potential as C4, but don't know how accurate that comparison is.
Propane can be used to produce just about the most powerful explosion outside of a nuclear bomb. Propane might not be specifically mentioned but it is what is used to make a fuel air bomb. Drop a 10 to 20 thousand gallon tank of propane into a jungle. Let the gas spread out on the ground for a bit. Then drop white phosphorus on it and you have an instant airfield and have killed everything in the radius of the explosion.
The key is air. That is why the tanks do not generally explode when shot. Not enough air mixed with the fuel and the bullet is not necessarily an ignition source.
Seams like once we the people give what, at the time, seams like a reasonable inch and "they" take the unreasonable mile we can only get that mile back one inch at a time.
No spelun and grammar is not my specialty. So please don't hurt my sensitive little feelings by teasing me about it.