I see it as a vermin barrel. Say you and your buddies were staked out in the woods and you had your trusty 99 by your side in perhaps 300 or 250. Now lets say some of the local vermin (snakes, rodents, politicians or what have you) got into your camp and gear during the night or when you were out walking the slopes. Now a 300 or 250 might be too much for dispatching such vermin but wait, you also happened to have packed along your 410 barrel. Vermin beware as the 410 would be on guard for dispatching all such unwelcome critters. So I see it as a vermin or, maybe also, a critter barrel.
