I found in the Goblin Camp 6 Barrels of Smokepowder and 7 Barrels of Firewine.
From lore about the Forgotten Realms "Following the destruction of Lantan during the Spellplague, many artificers considered the secrets behind smokepowder to have been lost.[5]" Looks like our goblins are brighter then we thought.
Also 20 pound barrels would be small kegs, not the size of the barrels we have. At that size an empty barrel weight 110 pounds so a full one would be around 500 pounds and should not be easily moved, much less carring a dozen of them.
Make Barrels unmovable if you need the exploding barrels for set pieces and please make them rare.
