spot light on a shot gun barrel?

I'd not use a shotgun with a light for coyotes or anything else, unless it's the only firearm I had (and if so, I'd promptly buy something else). You really don't need that 'big' of a light, as the buckshot or slug ain't going that far. I'd use a .223 or even a .22lr first. With a .223, you could shoot out to 200yds easy, aiming at the eyes. Just make sure you know what those 'eyes' are!

We have coyote problems. Neighbor who doesn't live there, has several hundred goats, and 8 wild hair anatolian guard dogs... We only have one Anatolian now... to keep the 'yotes 'honest', I regularly fire a 22 pistol out the back door, and even more often out the bedroom window. (I'd make a terrible neighbor, shooting at all hours of day and night!)

Had real predator problems here before... do feel for ya!

__________________
Luck is what happens when preparation meets opportunity. Seneca
Learning is not compulsory... neither is survival. W. Edwards Deming

Yes a shotgun isn't a good coyote Gun, unless there in your barn.