The revolver used to make men shoot high, the automatic shoots low as a rule from muzzle heaviness, the wrong angle the stock is placed at, and the uneven blow back (which latter I will explain later).
Single-shot pistols are generally of American make and it is very curious what defects they have in comparison with the French duelling pistol.
To begin with they have a stock too much at right angles to the barrel and much too small and narrow.
Next, the trigger is in the wrong place. The proper place for the trigger is so that you can just reach it with the first joint of the outstretched first finger. Pressing the trigger with the second finger is a ridiculous habit and, with an automatic pistol, results in making the pistol jamb burn the first finger with the ejecting cartridges.
The American single-shot pistols have the trigger so close to the hand that the trigger finger has to curl around the trigger beyond the second joint.
I never could understand how Chevalier Ira Paine, with his big hand, managed to shoot American single-shot pistols.
The trigger being too close not only makes pressing it difficult but makes it so that, instead of straight back, it has to be pressed to the left and sends the bullet to the left.
COLT AUTOMATIC PISTOL, MILITARY MODEL, CALIBRE .45