Abstract: A method of forming a bottle-shaped or other contoured metal container by providing a hollow metal preform having a closed end and a wall thickness that decreases progressively in a direction away from the closed end, and subjecting the preform to internal fluid pressure to cause the preform to expand against the wall of a die cavity defining the desired container shape. The method may be employed in pressure-ram-forming procedures wherein a punch is advanced by means of a backing ram into the die cavity to displace and deform the closed end of the preform.