Shot string might help really good skeet shooters if they happen to lead a target too far. Most of the rest of us are far more likely to underlead rather than overlead, where doesn't help at all. And the really good skeet shooters probably don't need the help.
Might also help guys pass shooting waterfowl when they don't lead the first duck or goose far enough and end up killing one further back. But if they're shooting steel, that's less likely to happen than back when lead was legal for waterfowl. Because steel shot doesn't deform like lead, it doesn't string as much.
