[nonameiguess]

This is interesting to contrast with my experience as a former tank commander doing range gunnery with wooden targets and dry brush. Range fires due to machine gun fire happened all the time. They were not remotely uncommon or difficult to cause.

I know next to nothing about chemistry or materials science, so offer no explanation of why this would be the case but a gas tank is difficult to ignite. The only layman intuitive answer I can think of is that a high speed projectile traveling through wood generates a lot more friction than one traveling through a liquid or gas, and something has to happen to that energy.

[dwohnitmok]

Yeah as soon as you have a solid chunk of something to hit it's a lot easier to start a fire. E.g. it's actually quite easy to start a fire by shooting a lot of bullets into a gas station pump rather than a thin barrel.