All good suggestions. I'm curious though, it almost looks like the handles and jaws are more hollow than a heavy duty application, but I could Definately just be seeing it wrong. A couple of different angles may help? And maybe size, but I guess if one were thinking they may be a bullet mold that kinda describes the size... But just to be sure?
Bullet molds were made by first forming a hardened "cherry" that was slightly larger than the desired ball/bullet and squeezing the mold around that to form the cavity. This was invariably soft metal that would be hardened afterwards.
Later advances used bronze, brass or aluminum blocks with a sepetate handle. But until 1880 or so they were usually integral with the handles. That is - you would not find handles missing a seperatly formed mold.