One thing I keep wishing they would check is if hitting explosives like TNT or gunpowder causes them to explode. I can think of a few westerns and war movies where people are held up in a room full of TNT, gunpowder, grenades, etc and nobody takes a shot because they’re afraid of it going off.
I know they did that with car gas tanks. No they don’t explode, not even with tracer bullets.