We note with some amusement the proliferation of pistol lights in various configurations. We cannot actually call these things "coaxial," since the light and the bore do not constitute a single axis. However, the idea is there. Your illuminator should show you approximately where your bullet will strike, but we should not view this as a sighting system since its alignment is insecure and it tends to slow down the firing stroke. I experimented with this many years ago when we were still living in California, and found it more useful as a shotgun enhancer, in its combative sense. You are never going to improve your skeet score with a light or a laser, nor will you improve your tally on ducks, but it may be a distinct asset in house clearing situations. I believe the combat shotgun to be the most efficient house defense implement, and I think the light offers certain advantages in repelling boarders after dark. It is not widely offered in this fashion over-the-counter, and moreover it does not help the expert as much as it does the novice.