US Army M16 firing pin semi-solid steel injection molding program

1970s Army program that gave Flemings' group millions to injection-mold semisolid steel firing pins. Failed because no mold material could withstand the temperatures; 100 parts per $100,000 mold. Used to mark the limit of the semisolid process for steel.

This is the ceramic core that goes inside one of those turbine blades you're going to cast; it gets etched out with acid afterwards. These are some compressor discs. And here's actually the rheocast technology — the finished casting. These are Professor Flemings' drawings, in a book now. I recognize this as the firing pin for a US Army M16. The Army gave them millions of dollars back in the 1970s to see if they could injection-mold semisolid steel. This is injection molding — you're pressing semisolid material into the cavity, and the cavity is that firing pin. It didn't work because you didn't have mold materials that could even take those temperatures. They could make 100 parts on one $100,000 mold — not exactly economical.