 The armour was intended to provide protection against high-velocity guns in general use at the end of the Second World War.The weight increase with the third prototype was mainly caused by the larger turret and even in its fourth "uparmoured" form, doubling the frontal armour thickness, the AMX 50 was less well protected than its American and British competitors, themselves inferior in armour to the Soviet heavy tanks they had been created to fight.The fifth prototype used a lower cast hull, with a rounded frontal section for a better weight efficiency.