B17 bombers have auto pilots?

I've noticed in WW2 documentaries that pilots of B17's flew manually when in the "box" formation. Didn't these planes (1943-44) have some sort of auto pilot? If they did, why weren't they used when flying formation? And how did these waist gunners swinging .50 caliber MG's around avoid shooting off a wing? Did the guns have governors? Just curious.