RE: .410 & 20 gauge Slug Guns
At only 1/5 oz., a 410 slug is awfully light. The drop really isn't that bad, and they're fairly accurate.
That said, the 410 slug barely makes the minimum of 1000 ft-lbs of energy that is the "norm" for killing deer...at any range. Even though there have been many deer killed by them, there are just too many better guns.