Trigger control is the ability to squeeze the trigger of your gun without disrupting your aim. This essentially means being able to press the trigger straight back in a smooth, continuous manner.
The process of proper trigger pressure can be broken down into four basic parts:
1. Trigger Finger Contact: It is generally taught that the middle of the first pad of the index finger should contact the center of the trigger. The size of the firearm in relation to the shooters hand, trigger pull weight and personal preference allows for some deviation. For instance, shooting a double action revolver with a heavy trigger pull may require contact with the trigger closer to the first joint of the index finger.
2. Taking Up The Slack: Semi-automatic pistols have what is referred to as "slack" which is the little initial movement of the trigger which has little or no weight before the actual trigger press which causes the causes the gun to fire. The shooter can feel a distinct difference in the amount pressure needed to pull the trigger back through its slack vs the pressure needed to fire the weapon.
Slack is initially taken up as the gun is brought on the target so that by the time sight picture and alignment is acquired, the slack has already been taken out.
3. Trigger Press: This is where most problems occur. Many people, when they experience the weight of the trigger, jerk or pull the gun out of alignment. To avoid this, it is important to focus on only moving the trigger finger and keeping the rest of the hand gripping the gun still. Apply smooth, constant, even pressure, pulling the trigger straight back.
4. Re-Set: Once the gun fires, the shooter relaxes the trigger finger's pressure allowing the trigger to return forward preparing for the next shot. If no further follow up shots are required, remove the finger from the trigger, placing it outside the trigger guard.
Many trainers teach the trigger reset method where the trigger is released only to the point that another round may be fired. The shooter knows he/she has reached the reset point when they feel or hear a little click. Doing so allows the shooter to avoid having to pull the slack out again thus allowing for a faster follow up shot. The opposing point of view of some trainers is that under stress, shooters will not actually perform the trigger reset no matter how much they try to condition the response.
The 1-2-3-4 Shooting Process and Trigger Control
Gun control, no. Trigger control, yes
The Trigger-Reset Method Controversy