I am ever of the opinion that the tactical shotgun is a quick response short range weapon that is almost always best pointed rather than aimed. If not the usual bead front sight, ghost rings are ideal for that. If you insist on mounting a red dot sight, or worse, a laser, be aware that in the dark they will to one extent or another reveal your position to an adversary with either a soft or very definite red glow, the exception being a red dot unit that can be shielded with a lens cap at the front. An example of that is the Aimpoint PRO, which will in fact work very well in the dark with the downrange cap in place. With the downrange end closed off, you can still acquire targets very well in the dark, and the only risk is whatever faint red light may still be reflected off your face or eyewear.
