I shoot a Remington 870 with ghost ring sights and run a red night eyes headlamp. The front sight has a white dot and I set up my headlamp so when I'm looking down the sights the very fringe of the beam catches that white dot and lights it up very well.
I bought a VRL-1 and mesa tactical magazine clamp (with picatinny rail) to mount a gun light, but my partner has yet to buy a headlamp and so he has been using my gun light to scan with. Killed a double with just the headlamp setup Saturday night, one at 19 yards and one at 43 yards...bang flop. Don't know how much of a need I'm going to have for this here kill light LOL.