Good idea, questionable execution
This tool is well thought out, and does work, including on N frames with a little modification. The pilots, on the other hand, are brittle and prone to breakage with the tiniest bit of side pressure
Not good for N-frame S&W's
These will work fine for a K-frame on an N-frame that has a long cylinder and and a short breech end such as a Model 29. They will not work for a short cylinder N-frame such as a Model 27 or Model 25-2. There is not sufficient depth for the cutter to reach the shoulder.