Thucydides said:On the totally off topic issue of the subject at hand, there is one exception in automatic weapons that I can think of, being the 30mm RARDEN cannon, which has an insanely complex mechanism which allows use in a very compact turret (takes up less space) and also ejects the spent casings to the front so they fall (via a chute) outside the turret.
Necessity being the mother of invention was one parent of the development of the RARDEN (The initial driver was the need to arm very small vehicles with large and powerful weapons to deal with the Soviet threat), and British interest in Baroque engineering was the other parent, explaining the way it was actually designed and built. Even so, it has been a reliable and relatively popular weapon, serving for decades in many different British AFV's. It is set to be replaced by the 40mm CTA cannon, which uses an entirely different principle of operation and an unusual type of round.
As I recall, it used to have a three round box magazine, but that may have been changed later.