I have 2 Emperor MX5 shotguns available. Chambered for 3" 12 ga shells with a 4+1 capacity. It is equipped with a pistol grip, 18.5" barrel, ghost ring sights with a fiber optic front sight, and picatinny rails on the receiver and fore grip. $350 plus tax/shipping.
Based on what I have been able to research and find, this shotgun seems to cycle 2 3/4 just fine. I do not have any personal experience with this firearm though.