Bumbling around trying to find my feet in the game, and as part of that I have picked up what loot can be found, including after destroying barrels. Was doing the same in a location, and it was going fine. Must have busted an oil-lamp barrel and a few others, before destroying a gunpowder barrel. Any holy cow did that thing BLOW! Two people in my crew got fried almost instantly (including me) and others took very serious injuries.
Need to try to repeat that sequence in an actual fight, because that would probably take out several enemies. Very impressive stuff.
I write this more as a "have you seen or tried this yet?" than anything else. So try it out!: D