Oscillating turret

Their only widespread use was on two French designs: the AMX-13 light tank and the Panhard EBR armoured car; the Austrian SK-105 Kürassier uses a turret developed from the AMX-13.

In an oscillating design, the gun and the upper part of the turret move as a unit, so no extra room is needed.

Additionally, in a conventional design elevating the barrel of the gun pivots the breech into the tank hull, which requires the turret ring to be large enough to allow this.

This is necessarily weaker than a one-piece design, and so is less optimal for main battle tanks and other large armored vehicles.

On top of that the gap between upper and lower parts of the turret is rather hard to seal which results in problem with protection from elements, fording and making the vehicle NBC proof.

Size may be reduced because the non-elevating gun breech does not need to move up and down inside the upper turret.

The AMX-50 grew progressively heavier and although it might have proved a capable heavy tank by 1950s standards, this whole class of slow-moving AFV was becoming outdated by the development of lightweight anti-tank guided missiles in the 1960s and so the project was abandoned.

In French doctrine, light reconnaissance vehicles were heavily armed and expected to also fulfill a role in defending the flanks of a main force.

They were not expected to act as tank destroyers though, and so a high-caliber but relatively low velocity gun with high-explosive shells was effective in their role.

The French design used two six-round rotating magazines, allowing a high rate of fire and also a selection of two ammunition types.