What does it take to add a scope mount to a model 65 so I could use a red dot? Does the top strap have to be milled flat or is there a mount that would work just by drilling and tapping?

Drill and tap, plus you can get one that has sights and rail for red-dot.

You could also look into an Aimtech sideplate mount. When I purchased my 617 used it came with an Aimtech mount and Laseraim Illusion Red Dot scope. It's now been replaced with a J Point reflex on a direct mount because I didn't like the problems cause by the rather large offset from the barrel axis. However, it did work well when shooting at the distance that it was sighted in at.

The way it works is you remove the 2 lower screws on the sideplate and use longer screws to secure the bottom of the sight. At the top it wraps over the top strap and clamps to the top strap with 2 screws on each side. Obviously, it will leave some marks on the gun, however if you don't get stupid with those top screws the marks can be cleaned up with a bit of sanding. One issue was that the screw that retains the crane was a bit short, it only had 1 1/2 turns of thread engaged. Fortunately my 617 uses the later and larger screw to retain the crane and it's a metric thread, so it was easy to pick up a 4mm metric and fit it to the crane. However I did have to turn down the head so it fit the counterbore in the mount.

One additional benefit of this mount is that it's tunnled out so that the sights installed on the gun can still be used co-witness. In my case, that meant that the original target sight had been left on my 617 by the original owner.

Following is a link to the Aimtech mount. It's not perfect but it will provide an answer that keeps you from hacking up the top strap on your model 65.

Revolvers

Weaver makes a clamp-on style mount for K-frames. It uses just the elevation screw location and clamps over the front of the frame. It too leaves some slight marks, but on a stainless 65 I doubt they'd be noticeable. I've use the Aimtech sideplate mount and prefer the Weaver mount. It mounts more securely and doesn't have the hassle of the funky attachment screws.

Here's a pic of the Weaver mount on a Model 14:

The model 65 has no rear sight - could the Weaver mount be used if a hole were drilled and tapped where the rear sight would be?

Here is the mount that I put on my 10-32 .



Model 10 frame with a 32mag cylinder and barrel.

Bullseye,

Did you have to mill the topstrap or just drill and tap?
What brand of mount is it?