A missile launch cannister end cap removal device utilizing the pressure pulse of a traveling shock wave within the cannister is disclosed. A pressure chamber, the interior of which is separated from the interior of the cannister by a diaphragm having a selected rupture pressure. Gas pressure is generated in the chamber by the firing of an explosive charge at the appropriate time in the missile launch sequence. The diaphragm is ruptured by the pressure developed in the chamber introducing a traveling shock wave into the interior of the missile cannister. The pressure pulse of the shock wave removes the end caps fitted over the open ends of the cannister.