[Jacquerie]

Try lighting off a few lbs in your backyard.

[GingisK]

My first close encounter with black powder occurred when I was in the seventh grade. We used it regularly for rocket propellant until I entered college. I have purchased it and I have made it from scratch. Then we shifted to more energetic propellants like zinc and sulfur. I am intimately familiar with black powder. It is sensitive, but rather wimpy.

[GingisK]

What you missed mostly is the fact that the gunpowder was in a PVC pipe. Those pipes burst at 250-300PSI, which means the bomb wouldn’t develop enough pressure to cause much damage to something as durable as a railroad track. Black powder charges must be confined within a rather stout container so that useful pressure can be achieved. An actual explosive, like C4, needs only about a 1/2 pound uncontained charge to sever a rail.