 Construction of the individual sections of the new gun started in England at Sheffield Forgemasters and Matrix Churchill as well as in Spain, the Netherlands, and Switzerland.Bull concurrently worked on the Scud project, making calculations for the new nose-cone needed for the greater re-entry speeds and temperatures the missile would face.Over a period of a few months following, his apartment suffered several non-robbery break-ins, apparently as a threat or a warning, but he continued to work on the project.