RE: can 2 3/4 " slugg fit in 3" chamber
yeah 2.75s will work just fine, however if you had a 12g, and tried fitting 3.5s in a barrel that said 3in, youd end up takin it to the gunsmith to get em out.
with shotguns they awlays say how big ofa shell you can put in em, if it says 3in, you can put 3in, and 2 3/4in in it.
another thing ti remember is always make sure you have the right guage