Looking to mount a scope to my S&W 500 to use deer hunting. It has three slots on top of the barrel. What rings would you recommend? Mount three rings to secure scope or would two work?

In a heavy recoiling gun more rings are gooder.

The question is will the three rings fit your scope.
If they will, use them all

I used a Holosight on mine. Never came loose or lost zero.
Longest shot was on a large hog at 90 yards on a full run. I love Holosights on handguns.

Interesting comment on the Holosights - never thought about those... What brand works for you?

If TSOB makes mounts/rings for your handgun, by all means buy them and use as many rings as you can.

I gave up using scopes on my FA .454 some time ago- whether Leupold or Burris, they lasted 250 or so rounds apiece before going back to the factories for repair.

My FA now wears a JP Enterprises Red Dot sight, which works very well at ranges out to 100 yards. Extremely light, and less likely to fail upon recoil- something to consider, I guess.

Leupold Red Dots

This is perfect for a revolver. It is about the size of your thumb.

I use Eotech and Bushnell. They're kinda big but not too heavy. Once you pick up a 500 a few more ounces isn't a big deal. Best sighting devices to get on a target fast, in my experience.

I have Weigand Combat base and 3 ring set on my S&W 500 topped off with a Leupy 2x long eye relief scope. I have the gun sighted about 1.5" high at 100 yards.
John