Lawrence Livermore National Laboratory (LLNL) has developed a class of explosives having both high performance for modern precision munitions and greater safety for reduced vulnerability of launch platforms (ships, planes, ammunition storage sites) to enemy fire or accidents. Known as extrusion-cast explosives (ECXs), they have demonstrated performance levels equivalent to the most powerful now available, but test results indicate they are far less sensitive than the conventional high-energy explosives. Specifically, in a sympathetic-detonation test, ECX that was immediately adjacent to a deliberately-detonated donor charge did not detonate in two of three tests, whereas Comp B did detonate sympathetically in this test. Also, this ECX provided performance equivalent to that of the high-performance explosive LX-14, when tested in the TOW (tube-launched, optically-sighted, wire-guided) missile. This report describes the performance, vulnerability, and processing (at this stage of development) of this class of explosives. 9 refs., 18 figs., 11 tabs.