I have a no-dash 686 that isn't drilled and tapped for a optic mount. What are my mounting options besides having it drilled and tapped? This will be for a scope or red dot. TC

There's two choices that I know of.

Aimtech makes a mount that screws onto the side of the gun using two of the three existing sideplate screw holes. I have one and it works, but is difficult to get tightened down enough to keep it from moving around.

The one I like is the Weaver top mount. It clamps on tightly using the existing rear sight elevation screw slot in the rear, and the front of the frame itself. The front clamp leaves a very slight bit of burnishing on the blueing that shows if it's removed and you're looking closely. The mount does not move once it's installed. I have several of them on various K-38's and have no complaints. I have a few extras floating around that I'd sell, if you're interested. Here's a pic of one on a Model 14-3: