The constriction in your barrels is the difference between the bore diameter, and the muzzles. It really doesn't matter if the tapered choke is 2" long or 6" long. Since the bore diameter is .731" that would make the chokes .037" right and .035" left. I think your reasoning is suspect in computing the difference between the muzzles and any other diameter along the choke taper. .037" and .035" are definitely in the "full choke" range, as you would expect in a LCS Long Range gun that has not been modified. However the only way to know for sure is to pattern at 40 yards and measure the shot in the 30" circle, then calculate the % based on the ACTUAL pellet count in the shell you're using. Be sure to do a composite of at least 3 shots and preferably 5 shots from each barrel. Firing one shot and trying to calculate the % is like firing one shot from a rifle at a target and assuming that's the center of the group. Hope this helps. Silvers