Since same profile barrels were used for both 2&3/4 and 3" chambered guns I would look for gun with longer factory chambers called Duck grade and later Magnum grade. There are couple of benefits to this firstly resale value secondly it will have longer barrels and chokes will likely be on tighter side leaving room for opening per your personal requirements. Prior to buying one I would get to understand patent 1797320 as you want gun with some room left for due to wear. I hope that helps.