The object of a bench rest is to provide a stable and repeatable platform for executing a string of shots. True enough. Is that not also exactly what the prone position can do? Bill Pullum and Frank T. Hanenkrat say the prone position should provide a sight picture that is motionless and that an experienced shooter should easily be able to hold a scoped rifle on the inside of a single .22 caliber bullet hole at 50 meters. A .22 caliber bullet hole at 50 meters is less than a half-minute of angle. In comparison, the 10-ring on a UIT target is one full minute and the 10-ring on the 600yard NRA Highpower Rifle target is about two minutes. To achieve this half-minute hold, it is necessary to learn and employ what the U.S. Army Sniper Training Manual calls the three elements of a good position: bone support, muscular relaxation, and natural point of aim.
Bone support and muscular relaxation provide a system in which the weight of the rifle is transferred from bone to bone, and ultimately to the ground, without being interrupted by any special muscular effort. It is very important to understand this concept. If one were standing on a street corner and decided to unconditionally relax every muscle, the body would collapse into a heap. It is easy to agree, however, that standing can be done while remaining fully relaxed. Standing, after all, is something routinely performed without any special effort. This is exactly the sort of relaxation that is required in the prone position.
The third component is a natural point of aim. Using the bench rest example again, no shooter would lower the point of impact by pressing down on the rifle while trying to slowly pull the trigger. Rather, the front rest or rear bag would be adjusted in preparation for making the shot. One could also visualize a mannequin with a rifle glued in place. The mannequin's natural point of aim is what it is. The only possible way to get the rifle on target would be to move the mannequin and, therefore, the rifle, right or left, up or down - just like the bench rest. The prone shooter, then, must learn to similarly adjust their point of aim.
In order to achieve a solid prone position that allows the shooter to maintain the proper bone support and muscular relaxation, it is necessary to learn the basic principles of the position. It is interesting to note that there are widely differing ideas about this perfect prone position amongst top scoring shooters. However, according to Pullum and Hanenkrat, this is not the least bit strange. They explain that, within reasonable bounds, specialized variations based on physical size and other factors are to be expected. Nevertheless, the basics are not to be overlooked, and variations that violate the three elements of a good position must be avoided.
The basic principles can be thought of in several logical groups. These groups are the left arm and hand; the right arm and hand; the legs and spine; and the head and neck. The discussion begins with the left arm, hand, sling and handstop.
World-class prone shooter Ernest Vande Zande says the most common error prone shooters make is developing a position where the left elbow is not extended far enough forward. The left elbow should be fully extended and set just to the left of the rifle. The placement of the left elbow should not be the enabling factor for building a "high" or "low" prone position. "High" and "low" prone positions are just what they sound like. A "high" position is one in which the left hand and indeed the entire position is high off the ground relative to what would be the lowest possible legal position. Moving the left elbow farther out to lower the position or closer to the body to lift the position is a mistake.
The left elbow is the single foundation point of the entire position. Everything else is adjusted and oriented around this point.
The sling running from the upper left arm to a point on the rifle near the left hand forms a triangle with the upper left arm and left forearm. The sling must transmit the rifle's weight to the bone in the upper left arm, thus removing the need for the muscles in the left arm to hold this weight. The sling should be made of a material that does not stretch and is as wide as the rules allow. A sling that stretches will allow the position to creep and become increasingly difficult to maintain without extra muscular effort. The sling can also slip down the upper arm if it is not adjusted snugly and held in place with some type of keeper. This can likewise degrade the position or cut off the flow of blood. Most shooting jackets have some type of hook, ring or strap on the top of the left arm expressly for this purpose. A heavy button sewn to the sleeve just below the sling will work just as well. A wider sling is less likely to cut off the blood flow as it spreads the weight of the system over a larger area of the upper arm.
The sling should be placed either high or low on the arm, but not in the middle. The brachial artery can become compressed between the sling and the bone when the sling is placed in the middle of the upper arm. A "high" prone position usually works best with the sling higher on the arm, and, conversely, a "low" prone position usually works best with the sling lower on the arm.
The sling should extend from the upper arm in a straight line on the inside of the left wrist. It should then pass flatly under the wrist and back of the hand to the connection point on the rifle. Pullum and Hanenkrat remind shooters to remove their wristwatch. It may also be necessary to adjust the cuff of the shooting jacket and/or the shooting glove under the sling at this point. It is certain that any extra bulk from a watchband or heavy jacket seam will become a distraction under continued pressure from the sling.
The use, utility and merit of cuff-type slings are left to the reader to discover.
On the "service rifle," the sling swivel is fixed and the shooter's prone position must be built around that fact. The length of the sling and, therefore, the height of the position are governed to a great extent by this fixed point. This is not necessarily the case when using a "match rifle." A match rifle may provide an adjustable hand stop that allows the position to be adjusted to any number of possible configurations. A good starting point for an adjustable hand stop is to arrange it so that the distance from the rifle butt to the trigger is the same as the distance between the hand stop and the trigger.
The position of the hand stop and length of the sling will govern the shape of the supporting triangle discussed earlier and raise or lower the position. These adjustments should not be initially tinkered with in order to achieve some desired higher or lower position. Rather, a stable position should be sought and then simply labeled as high or low. The point needs to be made that the position of any single element of the prone position affects all others. The arm bone is connected to the shoulder bone, to use a juvenile example. If after some experience with a particular position one is convinced that higher or lower might be better, then proceed to experiment with caution.
There are as many different types of hand stops as there are hands. Try several. Finally choose the one that is the most comfortable for the longest period of time. Using a hand stop that hurts like the devil just because Lonnes Wigger uses that type will only help Lonnes - not that he actually needs any help. When using multiple rifles, use the same type of hand stop on all of them, if possible.
The left hand and wrist must be kept straight, as any bending will cause extra muscles to be used and set up a springing motion that affects recoil. It is also important not to grasp the rifle with the fingers of the left hand. Any force exerted by the left hand will change recoil from shot to shot and thus the bullet's impact on the target. One may also unconsciously "finger" the rifle the last little bit onto the target when aligning the sights. This will result in shots that look and feel clean but are off call. Just as the trigger releases the supporting fingers relax and the rifle springs back to the true natural point of aim.
Once a stable position is established, record the length of the sling, the position of the sling on the upper arm, and the position of the hand stop. Index numbers are found stamped in many commercially available slings. If this is not the case, a simple black line marked with a "P" for prone can be employed. Many rifles equipped with an adjustable hand stop are similarly indexed. This notwithstanding, a piece of tape or any other suitable mark may be substituted.
As an extra note: If a journal is not currently being maintained - start one now.
The position should be oriented so that the spine is straight and relaxed. The left leg should be parallel to the spine with the toe of the left foot pointed in towards the position. The right leg should be brought up to about a 450 angle with the lower part parallel with the left leg and the toe of the right foot pointing out and away from the position. The angle of the right leg controls the relationship of the right shoulder to the center of the position and by moving the chest up and down, can control the effect of breathing. The individual shooter is invited to experiment with the right leg through the entire range of motion. It is an interesting experiment to set oneself in position and then observe the position of the right shoulder and chest as the right leg is swung through the entire possible range. A home video camera can be most illuminating in this particular exercise, as well as allowing general analysis of the position. Ultimately, one will determine the position of the right leg that is most stable and results in the least disturbance of the front sight from pulse beat.
In Full Metal Jacket, a stern faced drill instructor growls, "Move the rifle around your head, not your head around the rifle!" Exactly the same thing applies to the right elbow. The placement of the right elbow must be governed by the position of the rifle. To imitate the drill instructor, "Move the elbow to the rifle, not the rifle to the elbow." To achieve this, the shooter must grip the rifle with the right hand first and then plant the right elbow. It is also important to allow the right arm to relax normally when planting the elbow. No extra muscular effort should be used to pull or push the position into place.
Special care should be taken to guarantee that the right elbow does not slide around. A sheet of course grit sand Ppaper or emory paper should be in your shooter's equipment box. As needed, the surface of the elbow pad or shooting mat can be roughed up to improve friction.
The grip of the right hand should be just strong enough to hold it in place on the rifle. The fingers should be firm but not tight. The United States Army Sniper Training Manual explains that one will close the whole hand while pulling the trigger if the grip is not firm enough. This action of closing the hand along with pulling the trigger will move the rifle off target as the shot is being fired. A simple exercise will clearly show this action. While in the prone position with an empty chamber and un-cocked rifle, sight on an appropriate and safe target. With the right hand intentionally loose, pull the trigger and close the grip on the rifle snugly as one action. Notice the wild movement of the front sight. Next, try the same exercise while concentrating on not allowing the front sight to move. Difficult? Probably impossible. One might also extend this exercise using the correct technique to discover the best possible grip and hand position. This will be one that allows the trigger to be pulled straight back without disturbing the sights.
Master Sergeant James R. Owens instructs shooters that the position of the right hand must be such that the trigger finger is able to move without touching the rifle stock. The finger touching or brushing on the stock during trigger pull is called, "dragging wood." This makes it impossible to pull the trigger straight back or in a fashion that does not disturb the sights. According to Master Sergeant Owens, a symptom of this is a group of shots strung out horizontally.
The United States Army Sniper Training Manual agrees with Master Sergeant Owens, and further states that touching any part of the rifle - including the trigger guard - even at a slight angle will disturb the sights.
The butt plate should be placed close to the neck and have as much contact with the shoulder as possible. The larger the contact area is between the shoulder and the butt plate, the less likely it will be for the rifle to slide around and require constant adjustment. It will also be easier to keep a consistent cant angle if the butt plate has a large contact area. A rifle supported by the very top or bottom of the butt plate is free to swing on the pivot point created by the small contact area. The pressure on the butt plate should be equal to the pressure on the hand stop. This pressure should be adjusted by adjusting the length of the stock rather than the position of the hand stop or length of the sling. Recall that the position of the hand stop and length of the sling should be used to adjust the height of the position and front sight. According to the Small Arms Marksmanship Manual of the Bureau of Naval Personnel, insufficient pressure on the butt plate is the main cause of most weaknesses in the prone position. The upper body and right shoulder should be as close to the ground as possible. If a match rifle is being used, the height of the butt plate can be adjusted to help improve the amount of shoulder contact and pressure.
Generally, in the prone position, the cheek piece will be set such that the top of it is in line with the axis of the bore. With this in mind, the cheek piece should be adjusted to allow the head to rest in a natural position without straining the neck or shoulder muscles. A proper head position, in addition to being natural and relaxed, should allow the shooter to look through the sights without obstruction from the bridge of the nose or eyebrows. The position of the shooter's head can be quickly referenced using the sight picture. The position and relative size of the front sight as seen through the rear sight should appear exactly the same every time the head is positioned on the cheek piece.
In an article published in InSights, Joseph Roberts, Jr. says that seeing your sights the same way every time will keep you from making sight alignment errors. There is an explanation of sight alignment verses sight picture in the appendix. Ernest Vande Zande says that it is also important to move the cheek piece up and down with the rear sight. Keeping journal entries for how much the sight physically moves when adjusted from one yard-line to the next is key. If the rear sight moves one-quarter inch to move from 300 to 500 yards for example, the cheek piece should also be moved one-quarter inch. It should be understood that the physics of recoil include the weight of the head on the rifle. If during the first shot the head is being held up off of the rifle in order to align the sights and then during the next shot the head is pressed down firmly, the recoil will be different. This changing cheek pressure, and resulting different recoil, will cause the shots to be strung out across the target.
Recall any position must pass the test of remaining legal under the rules. It is the duty of every shooter to know and understand the rules. A visit from a match official in the middle of a string of shots can be pretty distracting. Pushing the envelope of legal is begging for a challenge.
Sight alignment error has a far greater effect on where a shot hits the target than does sight picture. The reason for this is that sight alignment is angular while sight picture is parallel. If you aim three inches off center (a parallel error), your shot will be three inches off at all ranges. If you misalign by three minutes (an angular measurement) a 600-yard shot will be three minutes (approximately 18 inches) off.
Each one-degree of cant results in a 1/4 minute change in impact. The use of a spirit level on a Match Rifle can prevent canting or maintain a constant intentional cant.
According to N. Kalinichenko, the spotting scope can be just as fatiguing on the eyes as the sight picture. He suggests in his September 1970 American Rifleman article, How the Soviets View Aiming Problems, that the same color filter be used on the spotting scope as is currently being used for the rear sight.
Pulse beat is the motion of the position generated by the beating of the heart. As the heart pumps blood through the vascular system, the pressure in that system changes and causes blood vessels to expand and contract with this change in pressure.
JD Hicks holds a U.S. record in Highpower Prone, is a High Master in Highpower Rifle and Long Range Rifle and has won State championships in three U.S. States.