The 28 would actually have a slightly longer range,
Please elaborate. Physics is physics, and the pellets don't care whether they are launched from a big tube or a small tube. It's mass x velocity and air resistance and gravity, once they leave the muzzle, all other things being equal. Unless the argument is that the trailing pellets fired from the smaller tube are able to draft behind the leading pellets better than those from the larger tube because of pattern dispersion.
Consistent killing range of a shotgun is not based on the penetration of a single pellet. It is rather based on a pattern sufficiently dense to ensure a lethal hit with pellets having adequate energy to penetrate. Therefore with the same number of pellets in the entire pattern, the one having a higher central concentration would have a slight range advantage with a "Center" hit. It would, of course, require a more accurate shot placement, with less room for error. Yes its based on physics, but there's more to it than just individual pellet energy. "IF" we were speaking of a single hit then a .22 short would be a far better killer than any of the above-mentioned loads, if legal & provided you were a good enough shot to place it where you wanted it.
