I use my regular 16 oz. hammer to punch. Next time I will try the rawhide hammer to see if there is any difference. The edges are a bit sharp so a quick sanding will be needed. I may try to tumble the discs first before sanding to see what happens. Once tumbled I may not even need to sand.
Since, this is my new tool from Santa I still need to really play and experiment. Santa had so much to do that he placed the order with Otto Frei.
The question now is - will this tool be cost effective?