The following information on using two revolver comes from Section 53 of Shooting by J. Henry FitzGerald. Shooting is also available to purchase in print.
Using a revolver in the right and left hand at the same time is the last word in practical police shooting and is, of course, for short range only. It is mentioned in the police section of this book because of the many cases where the gunman uses two revolvers or pistols. When two or more crooks are encountered by the officer at the same time it is very practical, if the officer has had experience in two-gun shooting.
The side draw is the same, except both hands move at the same time. The cross-stomach draw must be made one at a time or by swinging one elbow and arm outward to allow the other arm to move on the inside. In firing at two Colt Silhouette targets six feet apart and eight feet away the revolvers are pointed as one would point his finger and both triggers pulled at the same time. The sights are not used at this distance. A few shots fired in this manner will convince any one that this is a very practical way to shoot if occasion requires the use of two revolvers. A man with two revolvers and necessary experience is just twice as dangerous as one man with one revolver.
Anything the size of a man is, of course, a large target at eight to twelve feet and very easy to hit with two revolvers. This is, of course, double action and pointing, no sights used, the arm stiffened when the muzzle is pointed in the right direction.
I have had many of the gun-bugs look at me and shake their heads when I mentioned shooting two guns, but after a trial or two they ceased to feel sorry for me. In the settling of the West many two-gun men were developed and either gun would command respect. I am not advising every officer to carry two revolvers, but I know a great many who do, especially in cold weather. One small revolver, usually a two-inch barrel, is carried in the outside overcoat pocket. Two revolvers are also carried by many hunters and trappers who may not be able to reach a repair shop for many months. Accidents will happen and usually do when you are in a position to want a bullet or two mighty bad.
I may speak of a case where an old friend of mine in the game country fired his last shot from one of his revolvers and as he was only a few yards from his cabin decided he would go inside before reloading. As he stepped inside and closed the door he encountered one of the largest cats he had ever seen. He told me afterward that the second revolver saved his life, got him a fine pelt, and wrecked his pet coffee pot.
Another little incident happened to a police officer whom I know, who chased a couple of crooks into a blind alley. In the exchange of shots he emptied his revolver. As the sixth shot was fired by him they both rushed toward where he was standing before he could reload. They didn’t know that he carried another revolver and they are serving ten years each to pay for their blunder.