Jeff, if you are redoing checkering in old guns, please don't suggest "pointing up the diamonds". Most older guns had flat checkering, unlike what we consider "good" on modern guns. The pointed up diamonds on old guns just ruins them as far as I am concerned. A 60 degree tool is the "broadest" I would use and even better is one made much finer. I can't think of a vintage gun with the checkering made with a 90 degree tool.