Yes, a 3" chambered shotgun can chamber and fire any round down to a 2.75" round.
Once you get down to the specialty rounds like 2" rounds from Aguilla the shotgun may not function with those rounds without modification.
Hope this helps.

will safetly fire but may not function all semi autos

Hi David, Yes, most any shotgun is tested to function with Chamber Length and shorter shells.

yes it can however in some of the older design semi-auto (remington 1100) the action will not cycle after the shot so you would have to cycle the action by hand to load another shell the newer designs (remington 11-87) will fire and function (cycle the action) just fine with the shorter shells please select best answer and post again telling me hat make and model shotgun and i will give you a better answer

Yes, most any shotgun is tested to function with Chamber Length and shorter shells.

yes it can however in some of the older design semi-auto (remington 1100) the action will not cycle after the shot so you would have to cycle the action by hand to load another shell the newer designs (remington 11-87) will fire and function (cycle the action) just fine with the shorter shells please select best answer and post again telling me hat make and model shotgun and i will give you a better answer

Yes