I agree with CZ. Dave is addressing this from a driven shooting and he is well know for his kills at extreme ranges.
As I have mentioned in the past, last year there was an article in Fieldsports Magazine where a guy wanted a 28 bore set up for extreme pheasants. He purchased a Perazzi and had the chokes tuned to kill birds at 60 yards. In the article it seems it turned out successful.
I have read articles in the UK Sporting magazines where they have clubs that shoot partridges one day a season with 410's.

Mike Proctor