The low pressure 45 Colt could be what you are looking for. A 255 gr bullet and shoots a whole lot softer than the magnums. You can get loads that are light shooting cowboy loads or find loads that rival the magnum loads. I would think any with a 5 1/2 to 71/2 inch barrels would do.
I also like the single action for hunting with a handgun. My limit is about 50 yards on a shot, but no doubt it would work out to 75 or a 100 yards. This is my hunting gun when in close for shots on whitetail or blackbear. I've got a few deer with it but no luck on the bears.
It's a 45 Colt/acp Ruger Blackhawk with a 7 1/2 barrel. It will be a lot easier on that arthritis than the Magnums.