Get as high a grip as possible. Grip the revolver firmly but not tight with your right hand (shooting right handed).
Use your left or support hand to tightly grip the right hand and revolver.
Most of the pressure would be with the left or support hand.
Holding the grip too tight with the right hand causes the revolver to move when you press the trigger.
To determine the proper grip pressure, adjust the grip of the right hand until you can press the trigger without disturbing the sights WHILE DRY FIRING. Try different grip pressure to see how it affects the sights. Light to tight.
This is best determined dry firing with a laser sight.
If you have problems with your right hand it shouldn't matter since the grip pressure (in your case) would be from the left hand.
CPT USAR Ret
USAMU Sniper School Oct '78
Distinguished Rifle Badge 1071