I have a couple of Browning lights that have green LED's. I bought them for night-time hog hunting (legal here). Mounted with a rail mount, on an AR forend.
Even with an illuminated reticle scope, I found they were marginal at 150 yards, trying to shoot small pigs. I think they would probably work okay at 100 or less. I'll bring it if you like.
This one is larger, and has more range. Costs more too.
http://elusivewildlife.com/xlr-250.html