Why point the whole plane at the target. Why not moveable forward guns?

[major_setback]

I read an article yesterday about the first defensive guns in a WWII biplane. There was an ace who specialised in flying close to the enemy so that his rear gunner could pick them off. This way he didn't have to aim his whole plane at his opponent.

A moveable forward gun would eliminate the need for finely manouvering your whole aircraft in order to get the target in your sights.

Are there any planes that have moveable forward firing guns? I know the Defiant's rear guns could be rotated forward, but I wasn't thinking of turrets, but of remotely controlled guns.

Such a thing might be too bulky to implement in the wings, but could maybe have fitted in the nose of double engined aircraft. The housing wouldn't have to be very big. you would only need a few degrees of movement to get tricky targets into your sights.

The Black Widdow had a remote forward firing turret but as far as I know it was plagued with problems (buffeting) and was eventually turned into a fixed gun position. Are there any others? If not, why?