SWAW Operation HARDTACK Warheads Division 11 Jun 57 Lt Brown/ecm/2651 1. Inclosed for your information is the revised version of the Cperation Ground. It should be emphasized that this information is very preliminary and HARDTACK schedule which is planned for the Spring of 1958 at the Pacific Proving will undoubtadly change considerably prior to operation time. ?. Periodic revisions will be made to this schedule and will be forwarded accordingly, 1 Incl (CONF) (UNCLD), SWC 7830,266/18 3 pes (SRD) DORENCE C, JAMESON Lt Colonel, USAF Chief, Warheads Division AFWL/ HQ “a