I own two firearms, but am basically a know nothing. My Mossberg 590 12 gauge is now 20 years old --- only have fired it a few times, cleaned it regularly, but am now getting serious about setting up a home defense configuration in the house. The safe room will be behind two locked hollow core doors, with an intervening locked pocket door --- not exactly Fort Knox, but the theory is to just slow the crooks down, provide noise warning, and as they approach the second hollow core door, behind which we would be, provide a surprise through the door sufficient to knock one or more perps down/out of action. What would be the best round for this situation? Range - close. Stopping power - Max.