Suntracker,
FWIW in the M60 the TC could fire the .50 from inside or outside the tank. The controls were close to the middle of the cupola. The controls were a couple of cranks one of which had a button. That was the triger. One crank was for elevation, the other for traverse.
From the inside you had the optical site looking through the TC's periscope. If you fired from the exposed position you still used the same controls but looked over the gun to site it in. Frankly it was spray and pray for first burst hits. You had to estimate the elevation while above the barrel. If you were close to on target you could lay a burst quickly by adjusting. You didn't want to spray a lot as ammo was limited to one box and you had to expose yourself to reload. It wasn't particularly easy either.
Cocking the gun was done with a chain as there was no charging handle on this weapon due to lack of room in the cupola. A second chain was provided to fire manually if the electric trigger failed. There was no butterfly on the gun, just a back plate with a solenoid.
The advantage to being out of the turret was that you had better view of the area. The vision blocks just never gave the same view and restricted vision. It was a bit cramped as well.