Lead shot hardened with antimony has a density of 11.1 g/cc. I have tungsten shot with a density of 19 g/cc. Federal HW turkey loads have shot with 15 g/cc. The higher density shot is expensive and imported from China. It's too expensive for commercial loads (so far) and users pay from $45 to 60 per pound. In the overall scheme of things, shell cost is the cheapest element of turkey hunting.