How powerful is the a-10 warthog?

Depends what you put under the wings :)

But with no bombs, The A10 hosts the largest gatling gun in the History of Aviation, its called the GAU8 "Avenger"...The gun and ammo storage is so massive that the entire aircraft was designed around it. This monster has 7 barrels and fires 30mm rounds at a rate of around 4000 rpm. Rounds can tear through houses and armored vehicles.