With respect, a revolver is not a viable "combat gun" anymore. It's a great self defense gun, but clearly when we are talking about combat, we we are talking about straight up war time. 100 years ago, revolvers were the norm for war, but were quickly replaced with auto loaders. There are many reasons for this, and I'm sure any 1911 guru could extoll the virtues of a 1911 and why they became the official sidearm of the US military (only to be replaced by another autoloader) and continue to be used by special elite military units and law enforcement agencies. The point being, the revolver is no more a "combat weapon" than a muzzle loader or double barrel shotgun are. They may have been combat weapons centuries ago, but we live in the age of the automatic design for combat scenarios.
My vote goes to the 1911 as the greatest combat handgun, for it's design, ease of use, maintenance, durablity, and stopping power with it's war horse 45acp caliber.