Alright, so it would be a vehicle. It would be about the size of your blockhead. The blast radius would be about that of the HE-grenade. It would have to be a long time somehow before the barrel respawns itself.
You: "just use events"
Me: The problem is, when I go to make a realistically sized exploding barrel and I event it, the brick gets fakekilled before the OnProjectileHit event starts, thereby making it useless with most guns. Also, some new people don't know how to event and having a vehicle is much easier.
For the not instant respawn: Have the first explosion (the set on fire) be the big explosion, then make it have a "burn" time of like 15 seconds, then the final explosion is really small and does 0 damage.