I'd prefer GAU-8 more, a 7 barreled 30 milimiter depleted uranium hidraulically operated gatling gun that fires 4'200 rounds a minute.
Its the only gun that has a plane accessory, meaning, you dont attach the gun to A-10 Thunderbolt...
You build the A-10 AROUND the gun...
AFAIK it has enough recoil power to stop the plane if its flying too slow...
Its a nice
ratatatat! (watch till ending).