A method of forming a bottle-shaped or other contoured metal container by subjecting a hollow metal preform having a closed end to internal fluid pressure to cause the preform to expand against the wall of a die cavity (10) defining the desired shape, and advancing a punch (12) into the die cavity (10) to displace and deform the closed end of the preform either before or after expansion begins butbefore it is complete. The pressure-subjecting step is performed by simultaneously subjecting the preform in the die cavity to independently controllable internal and external positive fluid pressuresand varying the difference between them to control strain rate.