There have been quite a few mentions of Lanyard Rings for handguns in the recent issues of certain gun rags. The basis seems to be that it is not a good idea to lose your pistol while on horseback, or during a bear attack. S & W is even featuring these lanyard rings on certain 2005 models. For whatever the reason, a "lanyard ring" can easily be installed on any revolver where you are using the Hogue one piece grips. If you are not interested in a lanyard, this will solve the problem of mounting a rear sling swivel.
Remove the grip screw, grip and stirrup from the gun. The stirrup contains a threaded nut held in place by a thin metal bracket. Gently pry open the bracket, remove the threaded nut, and replace it with a square nut with 10-32 thread. The Uncle Mike's QD machine screw stud is 10-32 thread. You will also need to enlarge the hole in the grip escutcheon to allow the machine screw stud to pass through (3/16" worked for me).
Shorten the machine screw stud, if required, and use it in place of the grip screw. I used a thin stainless washer between the stud base and the grip. Note: Hex nuts will work, but may not hold while tightening the lanyard ring. If that is a case, a little J-B weld will fix the problem. Brownells sells the machine screw studs separately, if you do not have one lying around.
If you are working with a Raging Bull, or similar revolver with a factory grip, drill out the grip screw hole with a #21 drill, and tap to 10-32. Using Brownell's Do-Drill, or a similar cutting oil will make the job easier. Enlarge the hole in the grip, as above. With the Raging Bull, I had to stack 3-4 small stainless washers so the stud would clear the rubber recess in the grip.