A containment facility for a revolver has first and second opposed cups which embrace and seal against the opposed side faces of a revolver frame. The revolver cylinder resides within an aperture defined by the frame, and the cups enclose the exposed portions of the cylinder. The first cup defines a first internal space and has a first rim configured to conform with the first side face contour of the revolver frame, and encompasses the cylinder aperture with a first portion of the cylinder received in the first internal space. A second cup defines a second internal space and has a second rim similarly configured to conform with the second side face contour of the revolver frame, and encompasses the cylinder aperture with a second portion of the cylinder received in the second internal space. The containment facility includes flexible gaskets between the cup rims and the frame side faces.