I was standing next to a chap yesterday as we were shooting red leg partridges in the sunshine with a 30 mph downwind. He was using a Ceasar Guerini over/ under in 3" .410, and was very effective. It had 30" barrels and apparently weighed six pounds.
The sound of his gun's report was quite distinctive, as the loads were clearly supersonic. He was using 18 grams of English size 6, which is about 5/8ths of your old-fashioned ounces - can't remember the make.

HB