It's out to a member right now, it's made for a .22 cal, I added a .30 cal pilot from PTG, cuts a slight recess on a .30 cal barrel, here's a pic of a 223 barrel I crowned with it, the recess is ~.400" wide, and a pic of the tool with a .379" pilot I made to do a couple 38-55s, it's more of a facer and crown cutter on 30 cal and bigger.
Tim