Abstract: A method and means for sealed joinder of case and cap members of a capsular shaped charge wherein opposing frustoconical shoulders are formed in adjacent walls of a case and cap and a resilient ring is retained therein to hold the case and cap in operative assembly and an elastomeric ring is positioned in a groove in the case member whereby it is under compressive deformation between the case and cap members when joined to seal the shaped charge from external pressures and fluids while allowing relative rotation of case and cap; wherein increasing external pressures, as in the well bore, will increase the sealing effect and strength of joinder of the assembly.