Shaped charge liners, typically used in perforating guns, are formed from a zinc alloy of zinc and other metals such as aluminium and magnesium. The liners are formed into desired shapes, for example, by melting ingots and casting the alloy, or by machining bars formed from the alloy, or by stamping...http://www.google.com/patents/US6668726?utm_source=gb-gplus-sharePatent US6668726 - Shaped charge liner and process
