LEARNING OBJECTIVES With the aid of references, identify the characteristics and nomenclature of the ACOG scope. Without references, demonstrate the proper mounting of an ACOG to the weapon. Without references, demonstrate the use of the ACOG scope’s Bullet Drop Compensated Reticle. Without references, conduct maintenance on an ACOG scope. Demonstrate by scored live fire, marksmanship up to 800meters using an M16A4/M4 MWS with an ACOG scope during daylight hours. Demonstrate by scored live fire, marksmanship up to 300 meters using an M16A4/M4 MWS with an ACOG scope during periods of darkness/reduced visibility.

INTRODUCTION TO THE ACOG SCOPE TA31F TA31RCO

DESCRIPTION The ACOG scope is a lightweight, rugged, four power optical scope. Designed for the M4/M16A4, the ACOG provides an “auto ranging” reticle for ranges up to 800 meters. Through the use of both fiber optic and tritium the ACOG is dual illuminated during both day and night without the use of batteries.

RUGGED

CHARACTERISTICS 4x magnification. 32mm objective lens. Weight = 15.3 ounces w/M1913 rail adaptor. 32mm objective lens. Waterproof to depth of 66 feet w/adjuster caps on. Eye relief 1.5 inches. Field of view at 100 yds. = 36.8 feet Adjustments (3 clicks = 1 inch @ 100m)

CHARACTERISTICS CONT’D The TA31F ACOG does NOT have an ocular laser protection. Do not use the scope unless you have proper eye protection (SPECS-3 laser goggles), or lasers are not in use, or risk mitigation measures are in effect. Example, PEQ-2A in combat mode.

CONTROLS & INDICATORS Fiber Optic Light Collector Tube Ocular Lens Flip Caps Objective Lens Adjuster Cap Retention Lanyard LASER Filter Unit SRD/killFLASH Adjuster Protective Caps Body - Forged 7075-T6 aircraft aluminum alloy housing; Dry nitrogen filled to eliminate fogging Ocular Lens – Longer eye relief and large exit pupil for faster target acquisition TA31RCO also has a Modular Anti-Reflection Device (ARD) with an adapter for an integrated Laser Filter Unit (LFU), and a Signature Reduction Device (SRD) with a flip-up scope caps front and rear. A retaining band holds them together. ARD Adapter M1913 rail adaptor Mount with Thumb-Screws Adapter/LFU/SRD Retaining Band

ACOG USE Due to the use of tritium and fiber optic light devices the scope will allow the use of the Bindon Aiming Concept (BAC) of shooting with both eyes open. The ACOG can be used to “scan” an area. When a target is acquired, use the ranging reticle (if time allows) to get an accurate range to the target. Use the range aiming point on the bullet drop compensator, and engage the target. The scope can also be shot with holding only one eye open. (Preferred method for farther targets.) Human vision is based upon a binocular (two eyes) presentation of visual evidence to the brain. The word binocular literally means using both eyes at the same time. We most often associate this word with binocular instruments such as field glasses or a binocular microscope. These instruments specifically strive to present the object to be viewed the same way to both eyes. Vision research material was examined for its assistance to understand the optically aided weapon aiming process. Three major types of optical enhancement were compared. There are strong customer preferences in reticle designs, some simple reticles enhance the speed of target acquisition, others allow for greater precision in a given time limit. The simple substitution of a bright red dot for the usual cross-hairs makes it very easy to keep both eyes open. Just as in the Single point or Armson O.E.G. sighting, the brain merges the two images. During dynamic movement, the scene through the telescope blurs because the image moves more rapidly due to magnification. The one eye sees the bright dot against the blurred target scene, so the brain picks the scene from the unaided eye. The shooter swings the weapon towards the target while perceiving the dot indicating where the weapon is pointed. As soon as the weapon begins to become steady in the target area, the brain switches to the magnified view. A long search was made to try to combine the speed and non-battery features of the Singlepoint or Armson with the precision of the telescopic system. This discovery was made several years ago. Trijicon has sponsored research in the field of human vision to better understand this generic phenomenon. Although the study concentrated on the Armson O.E.G., some aspects are applicable also to the Bindon Aiming Concept.

RANGING FEATURE The horizontal stadia lines represent 19 inches at the respective ranges. (between 400m & 800m they should fit the average width of the frontal view of a man shoulders). Range your target using the width of the stadia lines. The outside legs of the Chevron equals 19 inches at 300m. Range Estimation is the process of determining the distance between two points. In most situations, one of these points will be the observers position, while the other may be the target or a prominent feature.

TARGET REFERENCE SYSTEM The TA31RCOM150 reticle includes a horizontal graduated in 5 mil increments. The distance from the centerpost to the first mil-bar on either side is 10 mils. The horizontal mil-scale is primarily used for communicating target positions. 10 mils Mil-Relation Formula - Requires you to know the size of the target (in inches). - Size in inches x 25.4 = size in mm. (constant). - Divide constant by Number of mils read. - Round answer to the nearest meter. Determine Constant Size of Object (Inches) X 25.4 = Constant Example: 67 Inches X 25.4=1701.8 Rounded = 1702 (Constant) Determine Range Constant Divided by Mil Reading of the Target = Target Range Example: 1702 Divided by 2.5 Mils= 681M While using the mil-relation formula, the key element is a steady position. Your position must be as steady as when you fire at a long-range target. If you are not steady, you cannot get an accurate mil reading. 10 mils 5 mils TRS

Outside of chevron legs target ranged at 300 meters Target engaged at center mass using the 300m post if time allows

Each stadia is 19” at the listed range

TARGET ENGAGEMENT 300 METERS OR LESS For target engagements requiring speed inside 300 meters place the tip of the chevron on a high chest hold.

300 meter and below rapid target engagement High chest hold

Target ranged at 400m

Target engaged at center mass using the 400m stadia

Target ranged at 700m

Target engaged at center mass using the 700m stadia

What range is this target?

Improvised adjustable reticle illumination. FIELD CRAFT Improvised adjustable reticle illumination. The chevron and front sight post can and will completely obscure and or overwhelm the target if you do not do something like this to counteract the effect of the flashburned image on the back of your retina.

Improvised adjustable reticle illumination Transitional light periods FIELD CRAFT Improvised adjustable reticle illumination Transitional light periods

Questions on the Ranging Reticle features?

EFFECTS OF WIND Same techniques of “hold-off” as with iron sights. Use of scope allows observation of bullet impacts not on target. Note the lateral distance from the target, and place that hold off to re-adjust and fire. Hold-off - A shooting technique used to compensate for bullet trajectory by using a modified point of aim above or below the desired point of impact. Also used to describe the modified point of aim used to compensate for wind or target movement. Also known as "Kentucky Windage." Wind is the atmospheric condition which has the greatest effect on ballistic trajectories. The amount of effect depends on: Time of Flight Wind Direction Wind Velocity Will normally have the most effect on the projectile from the midrange point to the target. 0-3 mph - Felt lightly on the face 3-5 mph - Causes smoke to drift 5-8 mph - Keeps leaves in constant movement 8-12 mph - Raises dust and loose paper 12-15 mph - Causes small trees to sway

MOVING TARGETS Utilize the same lead concept as in iron sight shooting. Lead your target considering the following: Speed of target Angle of target movement Range to target Wind effects Target Speed - As the target moves faster, it will move a greater distance during the bullet’s flight therefore the lead will increase. Angle of Target Movement - A target walking perpendicular to the bullet’s flight path will move a greater distance than a target moving at an angle toward or away from you. A target moving at a 45 degree angle will have less lateral movement than a target moving at 90 degree angle to a shooter. If a target is moving toward or away from you, no lead is necessary. Remember, the target range is constantly changing. Target Range - The further away a target is, the longer the flight time. The longer the flight time, the more the lead must be increased. Estimate range to target at point of engagement, not point of detection

MOVING TARGETS CONT’D Angle of movement: Angles of 0o to 15o should be engaged as stationary targets. Understand as the angle increases more Hold-off (Offset) is needed. Hold-off - A shooting technique used to compensate for bullet trajectory by using a modified point of aim above or below the desired point of impact. Also used to describe the modified point of aim used to compensate for wind or target movement. Also known as "Kentucky Windage."

Table shows the distance a target can travel during the time it takes a bullet to travel 150m

Bear in mind that your target will not likely move in a sideways fashion. Profiles are considerably thinner than the figure displayed.

MOVING TARGETS CONT’D If your target does not drop and you cannot observe impacts, INCREASE your lead. We increase lead because logically speaking, if you shoot in front of the target and miss, they will more than likely alter their direction of movement. If they continue to move in the same direction of travel we can assume that the shot was placed behind the intended target.

QUESTIONS? 30

TRITIUM SAFETY The ACOG scope is designed to handle field use, however severe impacts can damage the scope. Inspect the scope prior to use and after any severe impacts for tritium lamp glow. Tritium is a radioactive form of hydrogen, used in research, fusion reactors and neutron generators. The radioactive properties of tritium are very useful. By mixing tritium with a chemical that emits light in the presence of radiation, a phosphor, a continuous light source is made. This can be applied to situations where a dim light is needed but where using batteries or electricity is not possible. Rifle sights and exit signs are two examples of where this phenomenon is commonly used. The phosphor sights help increase nighttime firing accuracy and the exit signs can be life saver if there is a loss of power. The radioactive decay product of tritium is a low energy beta that cannot penetrate the outer dead layer of human skin. Therefore, the main hazard associated with tritium is internal exposure. In addition, due to the relatively long half life and short biological half life, tritium must be ingested in large amounts to pose a significant health risk. Tritium is a radioactive isotope of hydrogen. It is an odorless, tasteless, colorless gas that reacts with the human body in the same manner as natural hydrogen. Beta rays from the tritium hit phosphors to create the glow you see. Tritium has a half-life of 12.5 years, which means that in that time the lamp will be half as bright as it originally was.

TRITIUM SAFETY CONT’D If the tritium lamp does not glow, or if you suspect it may have broken due to damage, treat the scope in the following manner: Notify your chain of command. Handle only with rubber gloves. Turn in wrapped in two plastic bags. Wash your hands. Is tritium harmful?     According to documentation by health physicists in statements on file at the U.S. Nuclear Regulatory Commission (NRC), it would take the simultaneous rupture of 10,000 of these small glass capsules in a small room 10 foot by 10 foot to potentially constitute a radiation health hazard. For this reason, customers need not be concerned about the potential risk of the night sight system. Furthermore, our front sight is 0.018 curies and the two rear sight dots are 0.018 curies each. A complete sighting system is 0.054 curies. This is less than many tritium watches, which have up to 0.200 curies or roughly four times as much radioactivity. In addition, the weapon is not as close to the body, and in less constant use than a watch.

Identify inspection of tritium lamp requirements Recommend checking every 6 months, or immediately after dropping the ACOG onto a hard surface. Enter a dark room and look through the scope the reticle should be illuminated. Inspection is easier if the scope is already installed on a weapon. This ensures that you are focused on the reticle pattern. 33

QUESTIONS?

Care, Cleaning, Inspection, Mounting, and Zeroing Methods

LEARNING OBJECTIVES Demonstrate care and cleaning procedures Without reference, properly mount the ACOG to the M16A4. Without the aid of references, demonstrate the two methods to zero the ACOG.

CARE & CLEANING PROCEDURES If the lenses become dirty, the unit can be washed with fresh water and a clean cloth. Be careful to wash the lenses fully before wiping them with the cloth. The lenses could be scratched if dirt is pulled along the lens by the cloth

PRIOR TO MOUNTING THE ACOG

MOUNTING THE ACOG Place the ACOG on the receiver rail station that is suitable for the shooters stock weld and eye relief. (Most shooters use station T9). Tighten the interface knobs using your fingers, then apply an additional 1/8th to a 1/4th turn more with a screwdriver or multi-tool. Do not over tighten! Always put the same amount of pressure on the interface knobs when mounting the ACOG. This affects your BZO retention. Record the rail station! The ACOG can be removed and replaced with zero retention only if the same station is used. Witness Marks

MOUNTED ACOG * Location is shooter dependant. It is not necessary to shoot with your nose on the charging handle when shooting with any type of optics. The reason we used to teach this was to achieve consistency with sight alignment and sight picture when shooting with IRON SIGHTS. This is very important when shooting with Iron Sights because the shooter must line up three points in space (rear sight aperture, front sight post, and center mass of the target) in order to achieve the desired hit. With optics you need only line up two points in space (reticle and center mass of the target) to hit the target in the intended spot. You do not need your nose on the charging handle for proper eye relief!

BZO PROCEDURES ACOGs come factory preset for most M16A4 weapons, as such, only slight adjustments should be made. DO NOT OVER ADJUST. If you feel tension increasing as you adjust, STOP. Turn the ACOG into the armory. Continued adjustment past the felt resistance will damage the scope. The ACOG is only waterproof with the scope caps installed and not damaged. Remove and replace only when adjusting the scope, and only hand tighten. 41

TWO METHODS OF ZEROING 100 meter zero 25 meter combat BZO Zero shooting from a supported prone position using your ruck sack as a rest

Technical: True zero (100m) Establish a 100 meter target. Use a good prone supported firing position if possible. Fire 3 single rounds using the tip of the chevron as the POA/POI. (retighten then fire 3 more rounds before determining initial adjustments) Make adjustments for a point of aim point of impact. 3 “clicks” equals 1 inch @ 100 meters for both windage and elevation. Important: Obtain an accurate zero

100 meter BZO POA/POI Moving the adjuster in the direction of the arrow moves the strike of the round in that direction. 3 clicks = 1” For both elevation and windage (UP = move impact up) (R = move impact right)

Technical: BZO Establish a 25 meter target. Use a good prone supported firing position if possible. Fire 3 single rounds using the tip of the 300m Post. (retighten then fire 3 more rounds before determining initial adjustment) Make adjustments for a point of impact 1cm below point of aim. 12 “clicks” equals approximately 1 inch @ 25 meters for both windage and elevation. Important: Obtain an accurate zero Important: If you BZO the ACOG, confirm true zero as soon as possible at 100m. Make adjustments as necessary.

For both elevation and windage 25 meter POA/POI POA POI 12 clicks = 1” For both elevation and windage

Application: POA/POI 100m 200m 300m 400-800m

IMPORTANCE OF A PERFECT ZERO Although the TA31F is NOT a dedicated sniper scope, the importance of obtaining a precise zero must be discussed. If the shooter accepts a 25 meter zero that is off by only 1 inch, the round will impact 32 inches off target at 800 meters. Therefore it is critical to ensure the most precise zero possible in order to use the TA31F to it’s full potential. The next slide illustrates this importance.

Importance of a perfect zero Failure to obtain an accurate zero Does not take into account: Human error Environmental conditions Weapon/ammunition The graphical representation shows what can happen with a weapon that is fired from a vise using a mechanical trigger. Bear in mind that this is done when there is also optimum atmospheric conditions for shooting (ie no wind, extreme temperature, etc...)

ANY QUESTIONS?