You can make a hammer of a nice size with 3/4" copper tee wood hammer handle and a couple lengths of copper tubing. Pick up a 10 ounce ball peen hammer handle and fit the center ( single leg of tee to it squeezing in a vise to fit the oval of the handle). Cut 2 pieces of tubing 1" longer than the legs on the tee. A pipe cap can be used on one end. Use aluminum tape to seal plit and hose clamps to lock them on. Warm mould with a torch and melt lead. Pour into tube to full. when cool remove the tube ends and you have a hammer roughly 3/4" dia and 3" long. The lead heads will be 1" long and the tee helps reduce deformation around the handle.