No one has, as of now, found a choke profile that performs differently than a true conic of same entry and exit diameters. The reason is that the shot is behaving as a fluid and accelerates as it encounters the constriction. The shot does not "slam" into the constriction; it is an orderly flow. A profile that "eases" the shot into the constriction has little, if any at all, effect on the shot column. I realize that this is counter-intuitive and this is the reason so much effort has been wasted on "magic" chokes.

DDA