RE: Remington 1100 Question
Your 1100must have the magnum reciever to safely use 3" shotshells. 870s used to be marked with an "M" as part of the serial number if they were "magnum" receivers, not sure if that practice is still current or if itcarried over to the 1100, but it's likely that it did.
If the barrel that's on the shotgun is it's original barrel, chances are it is NOT a magnum receiver and should NOT be used with 3" shotshells.
As has been stated previously, there's still a lot of hunting one can do with a 2-3/4" chamber. The onlyspecies I've used 3" foris goose, preferring 2-3/4" for everything else (including turkey).