Mossberg 590A1 pump 9 round (2 3/4 shells), add a Vortex Defense rail system, EOTech M6X-000-A2 M6X-G LED light/laser system, and any other stuff! You can drop the stock for an even shorter CQB use.
How would that hold up after busting down a door? I must be cheap. I have black duct tape, excuse me, tactical duct tap, LOL. How about just taping a mag light to the gun?