The use of double taps is a technique best reserved for someone with plenty of skill with a
weapon. Skillfully employing a double tap requires more than simply pointing and squeezing the trigger. Over-zealous use of this method of firing can lead to unintentional
casualties, i.e. killing people you didn't mean to.
Note: See Blackwater.
To properly employ a double tap, rely on proper firing techniques. Most important, especially with pistols, is trigger control. Most people will encounter two problems when squeezing the trigger of a pistol:
1. Slapping - Slapping the trigger rather than squeezing it smoothly will cause the barrel of the pistol to pull to one side, usually towards the firing side. Even at short distances this will cause the round to miss the intended area, and in stressful situations this will be exaggerated.
2. Anticipation - Recoil anticipation is when the shooter anticipates the recoil of the weapon, causing them to grip the pistol grip more tightly. This will usually cause the barrel to drop down, throwing the round off drastically at even short distances.
Next, after trigger control, comes body position. The proper body position for combat shooting is to face your intended target directly. Square your body , meaning hips and shoulders should be facing the thing you would wish upon to layeth thy scunion. Next, firmly grip your pistol and grip your firing hand with your non firing hand. Your fingers should overlay, with one hand griping the fist of the other. Your arms (BOTH) should be firmly locked out, shoulders forward, head behind the pistol. Lastly, bend your knees, and lean forward as if you want to punch the target with your hand. Don't be afraid to squat over, but keep your back straight. All these things combined will give you proper body position.
If done correctly, when the round goes off, your good body positioning will cause the barrel of your weapon to naturally come back down on the original target. These steps are called recoil management, and without it you'll get kicked the hell out of country and be forced to change the company name cause you zapped a bunch of civilians you dumb bastards.