I believe you are thinking of the lethal potential of pellets shot from a shotgun and a single bullet shot from a rifle in the same manner, and this is I think you are mistaken. The lethal range of a shotgun is, in my experience, a function of both kinetic energy and pellet density.

If you also think of shotgun lethality as the total amount of kinetic energy delivered by all the pellets striking a target, then the more pellets striking that target the greater amount of total energy delivered. Remember that the pellets are spreading apart as they move downrange, so the denser patterns will always impact more damage to the target (especially at extended ranges) because more pellets are hitting the target. In general the more pellets you have to start with the denser the pattern further downrange compared to a less dense pattern with fewer pellets.

So, in my opinion, a shot charge that delivers the greater number of pellets inside a 10 inch circle at 40 yards will outperform one with fewer, all other variables staying the same (shot size, velocity, pattern uniformity). That charge will put more pellets on that turkeys head at extended ranges than the one with fewer pellets everytime.

Mouithcaller