But.... did I really have to?
Since the shotgun was being set up as a home defense unit, good looks were really not an issue. Effectiveness and speed of aiming were.
So, I ordered up one of these gadgets:
HiViz Plain Barrel Fiber Optic Shotgun Sight
It's a snap on barrel mounted fiber optic sight made by HiViz, one of the companies picking up stakes and abandoning Colorado in the wake of their political shenanigans.
It arrived from Amazon in only one day, and came in a blister pack with spare 'Light Pipes' in red and green. Several of each, in fact.
Frankly, I was skeptical towards it's ability to stay in place, and had already decided if it was deemed a suitable sight, it would be mounted with a few drops of epoxy.
After unpacking it and snapping it on the plain barrel 870 in question, I now see how they planned it to work. The unit does fit quite snugly, but can be slid around without a lot of difficulty. To keep it in place, they designed a notch in the front face into which the installer slides the bead sight most shotguns have. Once that's done, the bead becomes a recoil shoulder to keep the sight centered and in place.
For my use.... I'll still be stuck with the epoxy idea, having no bead sight to rely on.
How does it work? Not bad, actually. In any kind of situation with even a moderate amount of light, the sight glows strongly enough to attract the eye very quickly. In bright outdoor lighting, it's really very bright indeed, easily overpowering the background lighting to make sighting easy.
In darkish indoor lighting, it works... just not as brightly. It really does need some ambient light to kick in the glow factor. It's definitely NOT a night sight, but at $15 that would be silly to expect. On the flip side, a Meprolight night sight costs about twice as much, and functions fine in the dark..... but in daylight becomes just another front bead.
It's really a trade off, I suppose, and every shooter will have to determine their own needs. For my use, on this Remington 870 house gun, a simple and inexpensive fiber optic suits just fine. In fact, I'll probably try this widget out on my 590A1 for a while too, and see how it works on that boomer. If it does well, I'll order another.