It is entirely up to your tastes and abilities. I used to only carry 4 inch revolvers, but as my eyesight as aged, I have switched to a 7 1/2 inch bbl for my stand hunting gun. When I'm out checking spots during deer season, I carry a 6 inch open sighted revolver. When I'm out on the trap line or snowshoeing, I still carry a 4 inch bbl (Mnt Gun).
But for the critical accuracy at 50 yards, (from my stand) I use a scoped revolver.
Like I said...it is up to your skill and eyesight ability. Elmer had killed many deer with a 4 inch revolver as have many other well known shooter.