Typical 10 and 8-gauge choke constrictions may be easily calculated using high school math and a "direct proportion" by using the
surface area of a nominal 12-gauge .729" bore (Pi x R^2) and 12 gauge choke constrictions, and proportioning by using your measured 10 or 8-gauge bore diameter/surface area. Use 10-20-30 and 40 thou for 12-gauge IC-Mod-Imp Mod and X-Full). I could do that for you by hand or with an excel formula but as my sophomore high school professor Mr O'Hara used to say, that's your homework assignment.
Hey Mike, "a friend" suggested you give me a free round if I do that for you.
