(1) During the process of breathing, there is an alternating increase and decrease in the volume of the chest, as a result the person inhales and exhales. A person inhales when the dimensions of the chest increase. Once inside the lungs, the air provides oxygen to the blood and in turn it absorbs carbon dioxide and aqueous vapors. Exhalation occurs when all the muscles relax, the diaphragm presses upward, and, under the action of the weight of the chest and the elasticity of the lungs, air is forced out of the body. Exhaling does not require muscular effort; it occurs as the result of the resiliency of the ribs and the muscular tissues and the elasticity of the lungs.
(2) When breathing calmly a person produces an average of 12-13 respiratory cycles a minute. Consequently, one respiratory cycle lasts 4-5 seconds. If one traces the respiratory cycle, it is not difficult to note that the strained position of inhalation is replaced very quickly by exhalation. The very next inhalation begins after a respiratory pause of 2 to 3 seconds, (figure 1-7) during which time the carbon dioxide accumulates in the lungs. The duration off the respiratory pause is determined by the ratio of oxygen and carbon dioxide in the air remaining in the lungs.
Figure 1-7. Scheme of a Person’s Breathing.
(3) The respiratory pause and the problems of the ventilation of the lungs are of great importance to the shooter. It is obvious that during aiming and applying pressure on the trigger, the breath must be held only after the shooter has exhaled, timing it so that the breath is held at the moment of the natural respiratory pause. During that time the muscles are not strained and are in a relaxed state.
c. A person can prolong by several seconds this respiratory pause, that is, hold his breath comfortably for 15-20 seconds, without any special labor and without experiencing unpleasant sensations. This time is more than adequate to produce a shot or shots. Experienced shooters usually take a deep breath before firing and then, exhaling slowly, hold their breath gradually, relax and concentrate their entire attention upon sight alignment and the smooth application of pressure on the trigger (Figure 1-8).
Figure 1-8. Scheme of the Manner in Which A Person Holds His Breath in Order to Produce a Shot.
2. Recommended method
a. Prior to fire commands:
(1) When expelling the air from the lungs before aiming, no effort whatever must be exerted. The exhaling must be natural and free, as in ordinary breathing. The air must not be held in the lungs; incomplete exhaling before aiming leads to straining and to stimulation of the nerve centers regulating the breathing, and the shooters concentration on aiming is distracted.
(2) In order to make sure that during prolonged firing the interruption of the rhythm of breathing does not have an influence upon the shooter, the breath must not be held for an excessive period when trying to fire a slow fire shot. If the shooter does not produce a shot in 8-10 seconds, he must stop aiming and take another breath.
(3) Before holding his breath for the next shot he must empty his lungs well, taking several deep breaths. The same should be done between shots and strings of shots throughout the firing. This facilitates the lengthening of the respiratory pause before aiming and provides for regular rest between shots and strings. The oxygen level in the blood is slightly increased. As a result the shooter is relaxed and comfortable during all shooting without excessive and premature fatigue.
b. During the fire commands: Take a deeper than normal breath at the command, “READY ON THE RIGHT”, take another at “READY ON THE LEFT”, extend your pistol and take the final breath and exhale to the point of comfort at “READY ON THE FIRING LINE”.
As the shooter gains experience in proper breath control, he will find that he will hold his breath, or extend his normal respiratory pause, without being too conscious of the action and allow intense concentration on sight alignment and trigger pressure.
c. During actual firing: The shooter should not be conscious of the need to breathe. If during practice a shooter finds that he cannot hold his breath the twenty seconds necessary to fire a timed fire string, he should make a practice of firing his timed fire strings in less than twenty seconds. However, if during a timed or rapid fire string, the shooter feels compelled to breathe, he should take a short breath quickly and continue to fire. This causes a lapse of concentration on sight alignment and should not be the normal technique used.
CHAPTER II. SIGHT ALIGNMENT
Sight alignment is the most important contribution to firing an accurate shot.
In order for the bullet to hit the center of the target, the shooter must aim the pistol and give the barrel a definite direction relative to the target.
In theory, accurate aiming is achieved when the shooter places In exact alignment the rear sight with the top and sides of the front sight and holds them In alignment In the aiming area.
A requisite for correct aiming is the ability to maintain the relationship between the front and rear sights.
When aiming the front sight is positioned in the middle of the rear sight notch with an equal light space on each side. The horizontal top surface of the front sight is on the same level as the top horizontal surface of the rear sight notch (Figure 2-1)
A. RELATIONSHIP OF SIGHTS
It is necessary to be acutely aware of the relationship of the rear sight to the clearly defined front sight. Normal vision is such that the rear sight of the pistol will be as nearly In focus as the front sight. Some shooters may be able to see only the notch of the rear sight In sharp focus; the outer extremities may become slightly blurred.
Figure 2-1. The Relationship of the Sights.
1. Angular Shift Error: If the shooter does not observe correct aiming (maintaining the top surface of the centered front sight on a level with the top of the rear sight and equal light space on each side of the front sight) there will be few accurate shots. Most often, he locates the front sight in a different position In the rear notch. This accounts for a greater dispersion of shots on the target, since the bullets will deviate In the direction In which the front sight is positioned In the notch. (Figure 2-2). This aiming error is known as angular shift error.
Figure 2-2. Displacement of the Bullet When There Is Angular Shift Error in the Alignment of the Front Sight.
2. Parallel Shift Error: If the hold (arc of movement) is deviating In near parallel error from the center of the aiming area, the shooter should know that these deflections will not lower the score to the extent of angular shift error. Therefore, sight alignment is the most critical of the two. Thus, the accuracy of a shot depends mainly upon the shooter’s ability to consistently maintain correct sight alignment. The main effort should be toward keeping your sights aligned, Holding the pistol perfectly still is desirable but It is not mandatory.
Figure 2-3, Displacement of the Bullet When The Pistol is Shifted: (a) Parallel, (b) Angular
Figure 2-4a, Impossible! The Human Eye Cannot Focus On A Close-UP Object and A Distant Object Simultaneously.
