The gun pictured is not a 686. It's a 629. Anyway, you would need a laser designed specifically to fit in that area for it to work properly. It would be simpler to mount one on the rail. It's hard to tell from the picture, but it looks like there is a place to mount and accessory under the barrel in front of the frame.
Last edited by Shark Bait; 04-21-2017 at 06:44 AM.