Celebrim
Legend
I wonder if mythbusters ever tried the exploding barrel trick? Is gun powder packed tight enough in a barrel so it a BIG BANG or is just a BANG and you are ducking flying hoops?
There are enough incidents in history where there was a "BIG BANG" as a result of stored gun powder, and enough still extent ruins where the damage from the explosion is observable in all or in part, that I think we can establish that for enough weight of dry, well stored, finely ground and well compounded gun powder, there is in indeed a "BIG BANG". It won't look like a Hollywood explosion (which is typically mostly gasoline), and it won't be as brisant as an explosion from a high explosive, but it will still lift the walls of your star fort into the air or turn your giant man-of-war into a pile of splintered debris.