Rifle Sights and Optics
Military iron sights are more durable and repeatable than bargain bucket optics, rings and mounts. Reflex sights offer the advantage of maintaining a target focus. Magnified optics offer the advantage of target detection, target discrimination, light amplification, calling the shot and possibly spotting the splash.
Low Power Variable (LPV) rifle scopes are a compromise between the speed of Reflex sights and the optical abilities of magnified rifle scopes. Optics won't boost marksmanship but do assist viewing targets. Stable positions, trigger discipline and trigger follow through are critical to marksmanship. Under active conditions, carbines' reduced recoil, weight and bulk, make them easier to shoot than 7.62x51 rifles.
Minute Of Angle (MOA) is a common unit of measure found on many rifle scopes and some iron sights. Visualize a laser beam projecting a 0.25" dot at 25 yards, 1" dot at 100 yards, 2" dot at 200 yards, 3" dot at 300 yards and so on. That laser beam illustrates 1 MOA.
A 4 MOA laser beam will paint 1" at 25 yards, 4" at 100 yards, 8" at 200 yards, 12" at 300 yards and so on. In reality, there is also some rounding up, 3.4 MOA is actually 3.6" at 100 yards. It's nothing to worry about. Aficionados have to be pedantic. The key principle of MOA is that a small movement of the rifle bore has an expanding effect down range.
Tactical scopes have popularized the MRAD reticle, AKA Mil-Dot or MIL. MRADs and meters work together like apple pie and ice cream. Visualize an MRAD as a Metric MOA variant. One centimeter roughly equals the length of a fingernail. One MRAD represents 10 centimeters at 100 meters, 20 centimeters at 200 meters, 30 centimeters at 300 meters and so on.
Scopes featuring 0.1 MRAD clicks and MRAD reticles, permit fast zeroing by measuring the target with the reticle, fast
corrected fire by measuring the splash or bullet trace with an MRAD reticle and fast hold off due the MRAD expression
of adjustment. MRAD reticles are not locked into a specific caliber and cartridge. Fast tactical reticle ranging, AKA
"flash milling" is discussed in section (2.2).
1: Iron Sights
1.1) AR-15 Iron Sights:
Back Up Iron Sights (BUIS) fall into two basic categories, fixed and folding. Fixed BUIS compliment reflex sights. Folding BUIS mount under ACOG scopes and low power variable rifle scopes. This facilitates the ideal placement of the scope in relation to the shooter's eye, eliminating the requirement for a cheek piece.
Knowing the AR-15 sights' click value helps accelerate the zeroing process. However, different combinations of
sight radius, front post detents and rear sight design, preclude a standard value. Front post click value ranges
from 1.2 MOA to 2.0 MOA. The coarse click value may prevent an exact zero. Don't try to chase it. Windage click
value is between 0.5 MOA and 0.75 MOA. The 0.25" grids on sight in targets enable a simple MOA conversion.
Point blank range is the maximum hitting distance from a close range zero. Shooting within this envelope, doesn't require sight adjustment. A battlesight zero (BZO) is the best compromise between accuracy and point blank range. Locating iron sights above the bore results in the bullet intersecting the point of aim twice. The original M-16 BZO was set for 25 meters/300 meters.
This results in a maximum 8" elevation divergence at 200 yards. However, an expert qualified rifleman shoots 4 MOA, from field positions with iron sights. Tolerance stacking yields the actual max vertical divergence of 16" at 200 yards. The original BZO provided unsatisfactory hit probability under combat conditions.
The Improved Battlesight Zero (IBZ) delivers a max divergence of 2" out to 250 meters. That max divergence occurs closer in. The IBZ is only 1" high at 200 yards yielding a max aggregate divergence of 9" at 200 yards, once marksmanship is factored in. The IBZ is achieved by zeroing the sights at 50 yards/200 meters. The M-16A2 standard aperture was designed for the original BZO. The peep aperture was zeroed for 25 meters/300 meters.
The ghost aperture was integrally offset by 2.5 MOA, shifting zero to 50 yards/200 meters. Aftermarket same plane rear apertures, are better suited to the IBZ. The KAC Micro BUIS is pre-configured for IBZ. Set it to '2' and zero at 50 yards. Tritium sights have been superseded by weapon mounted lights. The TMC ambidextrous flashlight mount is compatible with A2, M4 and MOE hand guards.
The vertical mechanical offset between the AR-15 bore and sights, is responsible for negative divergence at close quarters. Compensate by targeting 2" high. AR-15 carry handles can mount optics but further increases mechanical offset. Mechanical offset can bite, if shooting from loopholes or cover. The sights clear obstructions but the muzzle may not.
A fist rest will stabilize and elevate the muzzle from deep obstacles such as car hoods. The simplest way to clear a loophole is to insert the muzzle through it and past it. A c-clamp grip functions as a rest. Rollover kneeling (aka Spetzsnaz prone), can be applied to shooting from low loopholes and under vehicles. Rollover kneeling is derived from a braced kneeling position, which speeds recovery to the standing position.
There are several tips to maximize AR-15 reliability under intensive shooting conditions. Steel cased ammo is acceptable for practice and plinking. Note that the bi-metal jacketed bullets shorten barrel life. Under high temperatures or high round count, steel cases may bind in the AR-15's chamber.
Modestly lube the bolt, bolt carrier and charging handle with Super Lube synthetic grease. This counteracts direct impingement burn off and remains operational in cold temps (-45F/+450F). It also acts as a carbon barrier, which accelerates cleaning. Incorrectly seated magazines and defective magazines are a major factor in mis-feeds. Use an authoritative push pull loading technique.
Proactive mag reloads prevent sand entering the action. Routinely pulling mags out, withstands failures to drop free. Initial and number magazine base plates to trace intermittent malfunctions. Routinely check loaded mags, by slamming the base on a table. If rounds fountain out, the feed lips excessively worn. Immediately destroy magazines confirmed as defective.
Downloading mags by 2 rounds, withstands a dirty guns failure to lock open and ensures a smooth rifle top off. Prevent damage and loss by not routinely dropping mags on the ground. Magpul PMAGS and Okay Ind Surefeed mags are both proven products. PMAGS are more rugged in the short term. Surefeed aluminum mags can be stored for decades, whereas polymer breaks down over time.
The StripLULA mag loader accepts loose ammo and bulk ammo stripper clips. Release a locked bolt by racking the charging handle, instead of activating the bolt catch. This technique withstands a dirty gun's failure to lock open.
A two fingered grip prevents flexing and breaking the aluminum charging handle. An upgraded steel handle is available. Clear typical malfunctions by ripping the mag out, locking the bolt back, drawing the charging handle back, slamming it forward and finally fingering the magazine well. Carrying a complete spare bolt, promptly resolves sub-component failures.
Short commando barrels or suppressors, may over gas direct impingement AR-15s. Heavy buffers will restore the cyclic rate and boost reliability. The restored rate permits cases to contract, extract and eject. Rounds can fully feed up through the magazine stack.
The heavy buffer's tungsten free weights, boost momentum, eliminating bolt bounce.
Carbines will function with the 6.5 oz buffer. Colt Commandos (6933) and suppressed carbines benefit from the heavier
8.5 oz buffer. An extra power buffer spring compensates for the additional buffer weight. Recoil reduction is a secondary
benefit of heavy buffers. Older AR-15 carbines shipped with weak extractor springs. The BCM upgrade kit resolved that
1.2) AK-47 Iron Sights:
However, the low velocity of 7.62x39 generates pronounced drop and consequently an arcing
trajectory past 300 meters. The bullet's steep delivery reduces the danger space, making it difficult to connect
with a mid range target. The bullet's low velocity and low sectional density, incur crosswind sensitivity at mid
range and beyond. However, 7.62x39 has superior barrier penetration and terminal ballistics to 5.56x45 NATO.
The less prolific AK-74 is chambered in flat shooting 5.45x39.
The standard AK rear sight is quite slow to acquire. Pictured above, Rifle Dynamics and Krebs Custom both offer a fast acquisition modification. Alternatively, use a needle file to open the notch by 1/32". Minimize distracting glare, by rounding off the top edge and corners and then applying cold blue. Paint the front post and protective ears with red modeling paint, to accelerate snap shooting and standard sighted fire.
The AK's low profile rear sight, assists the snap shooting technique covered in section (1.5). Pictured in section (2.2), the rear sight is also ideal for 1/3 co-witnessing with a scout mounted Aimpoint. The irons are unobtrusive but remain immediately available.
In contrast, the bulk of aftermarket AK-47 aperture sights, slows acquisition of both iron sights and Reflex sights. HK diopter sights exploit the brain's instinct to automatically center a circle within another circle. Installing an aperture rear sight on an AK-47, mimics the diopter system of the HK91.
However, in rapid presentations, the AK's front sight body will override it's adjustable front post. The HK fixed front blade, is permanently centered in the circular front sight body, eliminating such conflicts.
Two stage triggers prove advantageous under freezing temperatures, conditions of stress, exertion and engaging fleeting targets. The trigger pull gains weight in the final 10% of creep, indicating imminent hammer release. This enables the operator to stage and hold the creep at 90%. The operator command breaks the trigger, the instant the target and sights are aligned.
The K-VAR two stage, fire control group, incorporates small terminating bevels on the trigger and hammer interfaces.
This is simpler than additional mechanical lockwork. Stage one is 4 lbs. Stage two is 8 lbs. The tail on the AK
disconnecter prevents over-traveled F/A selectors, tripping the lockwork. A large rivet behind the disconnecter, eliminates
any trigger slap, induced by the disconnecter tail. A slave pin assists FCG installation.
1.3) FN FAL Iron Sights:
Refer to section (1.5) for HK91 rear sight usage. FAL stocks have a 14" LOP, which obstructs the groucho technique discussed in section (1.5). Fixed FAL stocks can't be cut down. FAL PARA stocks can be shortened at the factory or by the owner. The preferred LOP is 12.5". The optimal FAL barrel length is 18". The combo muzzle device acts as a barrel weight, which improves accuracy at the expense of some flash suppression. The inch pattern safety catch offers better ergonomics.
The FAL is the most rugged and reliable of the three Main Battle Rifles. Most notably in desert conditions. The HK91 is the easiest to accurize. The M1A is capable of best accuracy but requires the most maintenance to retain it. Typical FAL accuracy is 4 MOA for a 10 shot group. Extensive accurizing will improve it to 2 MOA performance. An entirely new FAL is capable of 1.5 MOA to 2.0 MOA 10 shot groups.
The HK91 has a reputation for being hard on brass.
An ejection port buffer reduces case dents and reduces ejection range to enable recovery. Full length resizing straightens
out most of the dings. The brass is ugly but reusable. M1A's are extremely hard on brass. Case life is four shots. The importation
of ZQI, MEN and PMC M80 ball, makes shooting MBRs more affordable. The brass is boxer primed and re-loadable. NATO 7.62x51 cartridges use
thicker brass and exhibit longer case life.
1.4) M1A Iron Sights:
The M1A's front sight is removable but not adjustable. The M1A utilizes the rear sight to set elevation zero. Consequently the elevation turret must be re-indexed after zeroing, quite like a target riflescope. The elevation turret is scaled in meters and calibrated for M80 ammunition. The M1A's elevation turret and windage turret have click values of 1 MOA.
Modified 0.5 MOA windage turrets are available. The
M1A's 25/250 meter BZO is physically zeroed at 25 meters, incorporating an offset point of impact of 46 mm. Save the M1A BZO target to your
computer for future use. If you are having issues opening the file, right click and select "save target as".
M1A BZO Procedure:
1.5) HK91 Iron Sights:
This requires a thin needle nose pliers and Phillips screwdriver. The set screw and lack of windage knob prevents the sight being bumped off windage zero. An optional windage knob is available. The #1 setting is specialized for assault/low light. Effective range is 100 yards.
The small V notch retains target acquisition under bumpy movement, such as shooting from a moving vehicle or engaging with rapid fire. Fill the rear V notch with the front ring as pictured above. The front ring remains visible in low light, long after the front blade has washed out. Fill the V notch with the ring and center the target in the ring.
The larger U cut out provides an unobstructed view for close quarters snap shooting. This technique is usually referenced as the Groucho position, the Universal Fighting Position or simply the Tactical Rifle Stance. Combined with baby steps, rolling the feet, it provides superior mobility, stability under movement, acquisition speed and muzzle control.
Effective snap shooting range is 25 yards. Shoulders, hips and feet are square. Shift the gun foot back, until its toe is parallel with the support foot's instep. Bend forward at the waist, shoulders over gun toe. The knees will sympathetically bend.
Mount the buttstock to the pectoral muscle, directly under the shooting eye. Maintain a cheek weld with a shallow muzzle depression. Square up to the target and focus on it with both eyes. Raise the muzzle and engage the target as soon as the front ring is encompassed by the target's silhouette.
This is decisively faster than hunting for a standard sight picture. Applying red modeling paint to the front blade and ring, further accelerates acquisition. Drop the ring into the V notch to engage targets past 25 yards. A shorter length of pull (12.5") suits the technique.
The HK91 sight is calibrated for standard 145 to 150 grain M80 ball ammunition. A battlesight zero (BZO) is the best compromise between accuracy and maximum point blank range. Locating iron sights above the bore results in the bullet intersecting the point of aim twice.
Zeroing the HK91 sights at 30 meters (33 yards) also zeros them for 200 meters (220 yards). This delivers a maximum aim/impact divergence of 3" within that range. Sight setting #1 and #2 have the same point of aim. Zeroing #2 at 30 meters also zeros #1 at 30 meters.
Switching to #2's peep increases the depth of focus, making the sight picture sharper. If the #2 setting has been zeroed at 30/200 meters, then #3 is zeroed for 300 meters and #4 is zeroed for 400 meters. Sight in targets incorporate grids of 0.25" squares to assist calculating zeroing adjustment.
A quarter turn of the HK91's elevation or windage adjustment
equates to slightly over 1 MOA. Filing the corners of the front blade to an arrow point, provides a more precise point of aim.
1.6) Remington 870 Iron Sights:
The 870 design requires a lot of manual fitting and polishing for maximum reliability. The economy express model features less testing, fitting and polishing than Wingmaster or police models. A used Wingmaster featuring the post-1985 'flexi-tab' proves to be the best value for tactical use. Brenneke slugs deliver superior accuracy and penetration to Foster type slugs. Battlesight zero for 12 gage slugs is 50 yards.
Tactical buckshot can be accurate out to 25 yards. Standard buckshot has roughly twice the spread. A bead front sight proves quickest for a dedicated buckshot shotgun. The extended range of slugs require open rifle sights or ghost ring aperture sights.
Ghost rings have proved more reliable than the classic 870 rifle sights, which were vulnerable to getting bumped off zero. However, ghost rings are slower for close range work. Shooters can look over the rear classic rifle sight for close range speed. Remington developed new low profile, express rifle sights for the DEA, which deliver reliability and speed.
The sights are sold pre-installed on 18" barrels. The rear sight is drifted for windage zero adjustment. The front sight
can be drifted out of its base. Elevation zero is adjusted by installing the appropriately tall front sight. The Choate
Mark 5, youth buttstocks, best suit the Groucho snap shooting position discussed in section(1.5). The standard plastic 870
follower can break, bind on a magazine extension or over compress the magazine spring. The Nordic improved follower eliminates
1.7) MP5 & Uzi Iron Sights:
BWE offer a modified Uzi sight leaf, which converts the 200 Meter peep, into a same plane 100 Meter ghost ring. The sight retains the original 100 Meter peep. The MP5 and Uzi ghost rings also assist low light acquisition and co-witness with micro reflex sights. Zeroed at 25 yards, the 9x19mm cartridge has a point blank range of 100 Meters.
Although subject to additional regulation, short barreled MP5s and Uzis are a real crowd pleaser at the range. Their minimal recoil and muzzle blast guard against developing a flinch. Their extra mass and additional points of contact, make them much more stable than a handgun. Accurate rapid fire is effortless.
A large stock of ammo, magazines and mag bandoleers, supports
uninterrupted semi-automatic blasting. Magazine bandoleers can be stored loaded in 40mm ammo cans. B&T offer an innovative MP5
speedloader that strips five rounds directly out of their packaging. The IMI Uzi speedloader accepts five manually fed rounds.
An additional Uzi magazine may be used as a two handed plunger.
1.8) Hexsite Handgun Sight:
Force On Force training spread from specialist military units to SWAT teams and select groups of handgun trainers. One of the big take aways from FOF training was that static fire was ineffective inside 21 feet. Shooters that rapidly moved off the line of attack, got shot or stabbed, much less than static or retreating shooters.
Moving laterally or obliquely, forced the aggressor into a Boyd OODA loop. This provided the victim enough time and space to catch up and defend themselves. Ideally the armed citizen would keep moving as it made them a harder target. Point shooting proved decisive as it supported shooting under rapid movement.
However, referencing the slide in peripheral vision remains disconcerting for many shooters. Hexsite equipped pistols are aligned by looking through the sights and focusing on the target. Point shooting is effective to 20 ft. Hexsites are effective to a minimum of 50 yards.
Practical handgun shooters suffering from Presbyopia will also benefit, as they don't need to focus on the sights to be an accurate shot. Seasoned shooters with good vision will need to retrain to overcome their conditioned front sight focus. The final characteristic of the handgun Hexsite, is that it resets and tracks like a shoulder arm. The front sight doesn't wander.
The drop step technique enables a rapid break from the line of attack. To move right select the right foot. To move left select the left foot. Take a step, pointing your foot in the selected direction. Land on the ball of the foot. Meanwhile, the rear leg extends backwards, landing on the ball of the foot and launching the body in the desired direction. The technique works on all surfaces except ice.
The Applegate shooting position was developed to support handgun shooting on the move. It's quite similar to the groucho position covered in section 1.5, except the support arm is perpendicularly outstretched in relation to the shooting arm. This acts as a stabilizer somewhat like a cat's tail.
The shooting arm is fully extended and in line the master eye with
a shallow muzzle depression. The elbow and wrist are locked. A convulsive grip is maintained to support follow up shots and
prevent "limp wristing". Pictured above, the shooter's body is driven on target. The shooting arm is vertically pivoted
at the shoulder, to bring the sights in line with the shooter's eye. The shooter engages the target after becoming aware
of the sights.
2: Rifle Optics
2.1) Economical Rifle Optics
It was one of the few scopes to withstand the punishing recoil of .50 BMG rifles. They were built tough with fixed magnification, heavy duty springs, steel adjustment gears, glass etched reticle and rear parallax focus. The reticle design used a .25" glass plate, which had much more engagement with the erector tube than standard wire reticles.
Canted wire reticles were a common failure point in rifle scopes. Fifty caliber recoil is perceived as equivalent to a 12 gage shotgun but the scope is subjected to almost ten times the shock of standard cartridges. The compensating muzzle break effect is faster than the human brain can sense.
The force and bi-directional nature of .50 BMG recoil, rips standard reticle's thin strips of wire out of their soldered connections. It stresses other scope components too. Occasionally, Super Snipers did fail under .50 BMG use but the lifetime warranty was always faithfully honored. As Leupold's MK IV price point escalated, the Super Sniper 10x42 gained popularity as an entry level scope, suitable for sniper competitions, which required an authentic MRAD ranging reticle.
The standard 10x42 Super Sniper works very well in a target shooting context but is not ideally suited to hunting or general duty. The 6x model retains the documented durability and repeatability of the 10x model but addresses these limitations.
Field of view increases from 13 ft @ 100 yards to 20 ft @ 100 yards, enabling tracking of moving targets 30 yards away instead of 100 yards minimum. Depth of focus increases to maintain clarity on objects several hundred yards apart.
SWFA utilized the standard full sized scope body to minimize development costs. This combination makes the scope very forgiving in 6x magnification. Shoulder the rifle and the sight picture is instantly acquired. The large objective lens, tube and ocular lens deliver a wide exit pupil, which eliminates the tunnel image effect, typical of budget scopes. Although sporting 6x magnification, field of view is almost on par with standard 4x scopes, making it suitable for hunting rifles.
A 14" length makes it less than ideal for tactical rifles, however it will fit an AR-15, M1A, FAL or HK91.
The 6X scope will focus down to 6 yards. Field of view and focus distance are not suited to close quarters shooting.
Use the the scope's elevation turret as a gross front sight and Groucho position discussed in section (1.5), to put
'metal on meat' inside 6 yards.
2.2) Reflex Sights
Peeps were also deficient against mobile targets, fleeting targets and targets masked by darkness, camouflage or physical concealment. Pump action shotguns, snap shooting, Rhodesian cover shooting, tracer ammunition, HK rotary diopter sights and M-16A2 ghost ring sights were partial solutions.
It was clear that optical sights could provide a comprehensive solution. The Normark Single Point collimator sight and the RADRE SUIT prismatic sight were intended to enhance the standard infantryman's advantage in all lighting conditions. British trials of the compact optical sights in the early '70's, found that soldiers hit probability increased at the expense of acquisition speed.
The SUIT received limited issue as a Designated Marksman sight. It would take another twenty years to source a viable reflector sight. Aimpoints were adopted by U.S. Special Operations Forces in the early '90's. Law enforcement and armed citizens' focus would broaden from shotguns to carbines, after the North Hollywood Shootout (1997). Broad acceptance of Reflex sights was the next logical progression.
The Aimpoint COMP Reflex sight (AKA reflector sight/Red Dot Sight) has several advantages over iron sights, collimator sights, prismatic sights and telescopic sights. The dot reticle is projected onto the target plane. This delivers infinite eye relief and parallax compensation. The dot ostensibly moves to compensate for different eye positions.
Unlike other sights, a consistent cheek weld isn't required for accuracy. Reflex sight acquisition is significantly faster than alternative irons or optics. Speed and practical accuracy are decisive in close quarters combat. Parallax compensation also supports unconventional shooting positions that exploit available cover.
The 1X magnification of Reflex sights supports shooting with both eyes open. This provides infinite field of view and superior situational awareness. Shooters can get 'lost in the irons' or 'lost in the scope', consequently enabling a bad guy to sneak up on them. Should the projected reticle fail, 1x magnification enables a transition to iron sights, while looking through the optic.
This ability to simultaneously view both sighting systems in known as co-witness. The Reflex sight should be mounted to situate fixed Back Up Iron Sights, in the lower third of the sight picture. Situating the irons higher will retard acquisition of the Reflex sight's dot reticle. It's practical for both sighting systems to share a common battlesight zero.
The Reflex sight's dot reticle is projected onto the target plane. Unlike iron sights, the target remains in focus throughout aiming. Fleeting and moving targets can be tracked. The simplicity of the dot reticle supports sighted fire on the move. The dot appears to float in mid air, somewhat like a video game.
Reflex sights don't focus light like magnified optics. They won't enhance a low light sight picture. However, the reticle is projected and therefore illuminated. Iron sights can be equipped with tritium elements but they often wash out the sight picture. Reflex sights' adjustable reticle illumination and both eyes open support, deliver a superior low light sight picture.
Reflex sights don't feature target turrets or graduated reticles. Inside 200 yards is their sweet spot. However, fire can be walked out to 400 yards reasonably effectively. There are a few tips to make this easier. Focus on the dot rather than selecting a specific point on the target. Try to maintain a consistent cheek weld at longer ranges.
Reflex sights still exhibit some parallax. Reduce the brightness to make the dot appear smaller for long range work. Boosting the
brightness makes dot faster to acquire at close ranges. Zero the dot with the top apex. This provides a more precise point of aim
and some hold off capability. A 4 MOA dot is the best balance of precision and speed of acquisition.
2.3) Low Power Variable Riflescopes
Low power, variable magnification, telescopic sights equipped with illuminated reticles, proved the most versatile. Reflex sights' and scout scopes' images washed out earlier in poor lighting conditions. High magnification scopes didn't provide the fast acquisition required for close quarters shooting.
Flash forward to 2007, the guys at the tip of the spear, came to the same conclusion. Aimpoints worked well inside 300 meters but struggled beyond that threshold, particularly under poor light. ACOGs worked well at medium range but their sight pictures were slow to acquire in close quarters. The ACOG's critical eye relief, required a very specific cheek weld, otherwise the shooter just saw black.
That specific cheek weld, didn't always happen under dynamic circumstances. Transitioning from bright to dark conditions, required a 15 minute dark acclimation, to view the ACOG's tritium illuminated reticle. Thus, a wish list was issued for an optic, which mimics a reflex sight at close range and a marksman scope at medium range.
01) Compact dimensions suitable for a carbine.
SWFA subsequently used the spec as a template for their new carbine scopes. The only divergence was the magnification range. Shooters preferred the 1x base magnification that was now physically possible. Historically, 1x telescopic sights often degenerated into negative magnification or fish eye effect.
A 1-4 x 24 scope was successfully released to market. However, research and development continued to progress, via customer feedback. The resulting 1-6 x 24 scope broke cover in 2013. It debuted an advanced reticle that supported shots from 1 meter to 800 meters. Six times magnification is the maximum for stable freehand shooting and mirage immunity.
Pictured above, at 1x magnification, the reticle resembles an over-sized EO Tech. Using the groucho position (section 1.5) to maintain a cheek weld, makes it practically as fast to acquire. The unlit circle is very fast to acquire and even faster with illumination. The eye is drawn to the symmetry and color of the lit circle. It brackets the head of a silhouette target at 3 meters (10 ft) and it's torso at 10 meters (30 ft).
The reticle's crosshairs are slow to acquire on 1x. Zero the scope at 100 yards using the pointed top post, much like the SUIT optic. Specifics will depend on the particular caliber and cartridge but MRAD reticles can be used for basic hold off out to 500 meters. Each MRAD often relates to an additional 100 meters hold off.
MRAD reticles support two ranging techniques, Flash Milling and Target Reference Point milling. Combine Flash Milling and basic reticle hold off, for rapid engagements inside 500 meters, which covers 80% of historical shots. To Flash Mil the 1 meter silhouette target, establish a stable position, place the top post on target's crown and read the number of MRAD to the crotch.
Mentally calculate the range in meters by dividing 1000 by the reticle reading. Leg bones are eliminated as they are responsible for the majority of height variation. Shooting targets must be 1 meter tall to support this technique. Flash Milling is particularly useful to the military designated marksman.
Range cards are populated by the map ranging, laser range finding and reticle ranging, of Target Reference Points (TRP). TRP milling supports a broader range of known dimensions than flash milling. Recording known dimensions in millimeters, enables calculating range in meters, through dividing the known size by the reticle reading.
Alternatively, calculate range in meters by aligning the known dimension (centimeters) and reticle reading on a Mildot Master slide rule. Practice milling with numbered cardboard targets of known sizes at known distances. Make the reticle fit. An MRAD monocular makes this feasible anywhere. Larger objects are more forgiving to mil.
The Mildot Master's inclinometer assists measuring tall objects. Aim at the top of the object. Height equals distance at a 45 degree angle reading. Measure the distance to record the height. TRP dimension logs consist of common objects and encountered objects such as telephone poles, doorways, oil drums, pallets, containers, vehicles and weapons.
Windage hold off is a skill in itself. Practice it separately from wind calls. The hash marks on current MRAD reticles often host multiple values to assist hold off without the clutter of Christmas tree reticles. It is possible to read the mid range wind conditions through a riflescope. Wind reading skills are developed through shooting. Rimfire or pneumatic .22 rifles make useful training tools.
Construct some wind flags with tent stakes and ribbons. Calibrate them with a wind meter. Practice reading the wind flags' speed and value in active conditions. Break wind speed into 5 mph increments. To verify, shoot subsonic .22lr rounds at extended range, for maximum wind sensitivity and maximum indication. Learn to use foliage as a wind indicator by placing the flags next to the foliage.
Eventually remove the flags and shoot to verify. The Dwyer pocket wind meter is an alternative to electronic units. It's light, robust, responsive and functions in extreme cold. However, the ball can occasionally bind. A supplied pipe cleaner dislodges the ball. Replacement balls are also available.
Zero the scope using the pointed top post, much like the SUIT optic. A 100 yard zero is practically immune to environmental changes, such as altitude, temperature and humidity. The MRAD reticle underneath the post, remains usable as a Bullet Drop Compensator (BDC). The gap between the post and reticle is 1 MRAD.
Long range shooters apply precise Data Of Previous Engagement (DOPE) to their riflescopes. The FDAC is a DOPE slide rule primarily developed for the Federal M118LR 7.62x51 cartridge. Select the correct DOPE based on current air density, which is expressed as Density Altitude. I would like to see some DOPE cards released for the MK262 5.56x45.
Calculate Density Altitude by selecting current temperature and current altitude from the integral chart. LCD temperature indicating labels
are more accurate than key ring thermometers. The FDAC is available in meters and MRAD expression. MRAD visualization becomes a lot easier,
if DOPE is expressed in meters and MRAD. Shooters will begin thinking in MRAD. One MRAD covers 10 centimeters at 100 meters, 20 centimeters
at 200 meters and so on.
3: Optic Mounts
3.1) AK-47 Optic Mount
HK claw mounts would pinch the G3's sheet metal receiver, retarding its bolt carrier. Fitting resolved that, at the expense of standardization. The M16's carry handle thumbscrew, walk loose under recoil. The M14 receiver had limited mating points, which proved problematic for many years.
Ultimately, the M4 carbine's integral picatinny mount addressed the aforementioned issues. It held zero and supported a return to zero of 0.5 MOA. The best mounts for other rifles, incorporate a picatinny interface, via a fixed, semi-permanent, milled mount.
AK receiver mounts and dust cover mounts are available. However, they are more vulnerable to zero loss because they're not fixed. Field strip necessitates mount removal or unlatching. The Israelis encountered this issue with the Galil's, dust cover mounted, rear sight. Pictured above, Ultimak's AK scout mounts are fixed, semi-permanent solutions. The unit is secured via barrel clamps. Loctite and witness mark hardware, after function testing.
The mount's integral gas tube, may be cleaned without removal. Gas tube removal is only required to clear a fouled gas port. Illustrated in section (2.1), should the optic's battery die, the Ultimak supports co-witness of AK iron sights. An operational Aimpoint with occluded objective lens, remains effective to 100 meters, if shot with both eyes open.
Beyond 25 meters, suppress Phoria by dismounting to a low ready, after each shot. An occluded objective lens and non-operational
optic, invokes quick release functionality. A low 30mm QRW ring works well.
3.2) FAL Optic Mount
Occasionally, the mount's ejection port may require relief and/or the ejector some stoning. Mounting Aimpoints with a low QRW ring eliminates the need for a cheek riser. The mount's rear cross slots can be shaved down to facilitate a low mounted rifle scope. An appropriate scope's eyepiece, is often larger than its objective lens.
Jeff Cooper promoted the 7.62x51 NATO (.308 Win) as his preferred general purpose cartridge. It has superior crosswind resistance to 5.56x45 NATO, superior barrier penetration to 7.62x39 and superior terminal ballistics to 7.62x39. The key advantages are versatility, availability and variety of ammo.
M80 7.62x51 ball is available from ZQI, MEN and PMC, costing 150% of surplus 5.56x45 ammo. Aficionados may disapprove but optics optimize the FAL's broad application. Past 300 meters, the human eye can't detect partial, fleeting, concealed or camouflaged targets. Historically, using iron sights on static, exposed, high contrast targets at 600 yards, led to optimistic assumptions.
Stability is the dominant factor in effective long range field shots. Sling tension offers effective stabilization in conventional prone, kneeling and sitting positions. However, this requires a free floating forearm, which adds too much weight to the already hefty FAL. The unconventional stacked feet sitting position, is very stable without sling tension. It's also quick to assume and comfortable to maintain.
Square up to the target. Squat down and sit on the ground. Extend both legs. Set the support-side foot on the trigger-side foot. Set the rifle forearm on the support-side foot. Grip the magazine well with the support hand and pull the rifle into the body. Adjust elevation by scissoring the feet. Adjust windage by pivoting on the buttocks. Foliage often precludes prone field shots.
The popular c-clamp grip technique supports rapid controlled traversed fire. It's currently applied to engage multiple targets at close range. Lead with the master eye, lock on the target, bring the thumb to target, engage and repeat as necessary. The technique was originally developed for the FAL by Rhodesian Fire Force units. Cover shooting was the primary Fire Force counter-ambush tactic.
Experienced bush soldiers would detect inconsistencies in foliage. Group fire would be immediately directed on that position. Subsequently,
each troop would prosecute his arc of fire, systematically engaging cover and concealment from close range to long range. The FAL's ammo was
capable of penetrating trees. Shooting rocks generated enemy spall injuries. Cover shooting was more effective than waiting to be ambushed and
subsequently attempting to locate the source of enemy fire.
3.3) M1A Optic Mount
However, almost all commercial M14 style rifles, don't conform to military receiver specifications. The Brookfield mount is incompatible with commercial rifles. Sadlak modified the Brookfield design for additional adjustment in critical mounting points. The Sadlak mount will mate with most commercial receivers. The Sadlak mount won't fit if a receiver's left side groove is too shallow. Sadlak offer a custom fitted mount for this contingency.
If a Sadlak mount has been purchased, a receiver inspection kit is available, free upon request. Sadlak use the inspection data to modify their standard mounts to custom fit. Rifles need not be shipped out. Several Sadlak models are available, solid steel, skeletonized steel (Airborne) and titanium.
Mount installation is quirky, check out the video demo below. Installation is semi-permanent. The mount offers enough
clearance to remove the rifle's bolt for field strip. A view channel supports iron sight use with the mount in place. Use low rings to minimize
scope bore offset. A cheek riser will still be necessary.
3.4) HK91 Optic Mount
Pictured above, the steel picatinny mount is welded to the steel receiver for absolute zero retention. The welded picatinny mount may also
reinforce the sheet metal receiver, reducing drop dent failures. Retro fitting a welded scope mount isn't an inexpensive venture. The extended,
low profile, Brugger & Thomet, HK91 clamping picatinny mount, has a proven track record. It doesn't block the rear sight.
3.5) Bolt Action Optic Base
One piece bases provide more mounting points to adjust eye relief. Their front and rear mounting holes are permanently aligned. A one piece base may be canted forward to maximize the useful adjustment of a long range rifle scope. Either way, it's worth investing in a proven steel product. Cheaper aluminum bases are vulnerable to warp and flex. Other issues involve low quality hardware, missing hardware, poor fit and finish, lateral cant, bowed bases and misaligned holes.
Leupold's two piece QRW bases support any weaver or picatinny rings. The bases have proven to be rock solid. If the budget won't stretch to a badger base, I recommend QRW bases over a cheap aluminum one piece base. The Badger maximized picatinny rail is the strongest one piece base available. It's designed to withstand the forces generated from mounting heavy tactical scopes to magnum sniper rifles.
Spacing the rings, prevents the scope's turret tower, becoming a torsion pivot point. Under rifle recoil, the base, rings and scope's inertia, walks them toward the muzzle. Pushing the base and rings toward the muzzle during installation, gives them nowhere to go. Recoil will tighten the ring's cross bolt nuts, if they are located on the right. It's relatively easy to over torque fasteners by relying on feel. The Wheeler FAT torque wrench is an affordable quality solution. Stripped hardware can be a real pain to extract.
The shooting sling has had a long association with the bolt action rifle. There are many designs but they all enhance stability by locking the buttstock into the torso and trapping the support hand. The bones of the support arm, rather than its muscles, now support the rifle. The upshot of this technique is almost double the stability in prone, sitting and braced kneeling positions.
The braced kneeling position benefits most, as it's the least stable of the three. The shooting sling boosts braced kneeling stability from 7 MOA to 4 MOA, for a 10 shot, slow fire group. Ten lunges each day makes the braced kneeling position fast to assume and recover. Many shooters don't like their arm wrapped up in a shooting sling. The VCAS is a high quality tactical sling, which can serve as a shooting sling in the braced kneeling position, without restricting the support arm.
The VCAS sling supports the offside drop ready position and a rapid transition to a slung kneeling position, without doffing the sling or wrapping the arm. Simply tension the sling and slide the support hand between the forearm and sling. The trick is to locate the front sling swivel, on the underside of the forearm, a hand widths away from the bottom metal.
The swivel serves as a handstop. Sling tension requires a free floated barrel and a rigid wood, laminate, fiberglass, carbon fiber or metal stock. The VCAS sling may be doffed an employed as a conventional loop sling for the sitting position and prone position.
Shoulder transitions enable shooting from strong side cover and concealment. To support shoulder transitions, locate the rear sling swivel high on the strong side of the buttstock, about one inch from the butt pad. This prevents neck constriction. A shoulder transition doesn't require a grip transition, which would be particularly awkward with a bolt action.
Slings can snag inside vehicles or in thick brush. Slide a ranger band onto the rear of the sling as an alternative to removal. Z-fold the sling
to take up the slack and tuck it into the ranger band. A quick tug on the sling will release the slack. Securing a sling's end points with duct
tape, prevents them slipping through their triglide and dumping the rifle.
3.6) 10/22 Optic Mount
The NDS-26 is a robust picatinny base with an integral rear sight. The Tech Sight front sight assembly (TSR110), utilizes the the 10/22's barrel dovetail, rather than just set screws. The extended front sight post (TS00182), makes the two units compatible. The front and rear sights are adjustable with tip of 5.56x45 cartridge. Loctite and witness mark, the front sight assembly's set screws, after function check.
Many gun models come and go, making logistics difficult. The prolific Ruger 10/22 is a sound platform on, which to base Project Appleseed. The project's expert qualification requires 4 MOA accuracy. The 10/22 is 2 MOA accurate, out of the box. The rifle has withstood, extreme carbine training courses and 10,000 round torture tests.
The Ruger 10 round mags and 25 round mags are most reliable. The 10/22 benefits from a Volquartsen extractor and Eezox dry lube.
Blow back actions project a lot of carbon into the receiver. Wet lube bonds with the carbon to form a troublesome sludge. Dry
lube stays where it's put. Winchester bulk ammo isn't hot enough for semi-auto actions. Federal AutoMatch is accurate and reliable
in the 10/22.
4: Optic Rings and One Piece Mounts
4.1) AR-15 One Piece Mount:
Forward cantilevered mounts also adapt standard eye relief scopes to match the AR-15's comparatively short receiver. AR-15 owners want a consistent centerline height between scopes and iron sights to generate a constant cheek weld. AR-15 iron sights have a centerline height of 1.4". Owners want sufficient clearance to mount a folding BUIS under the scope. Dimensions of scope oculars and BUIS vary but the standard clearance is 1.5". The KAC micro BUIS offers the most clearance.
Should a scope fail, quick release mounts can be quickly removed by hand. A folding Back Up Iron Sight (BUIS) may be flipped up and brought into action. If available, a replacement carry handle, fixed BUIS or optic may be attached. Mount removal does not occur in the middle of an emergency action.
The scope turret is used as a gross iron sight or a pistol transition is executed. If one arm is injured, the AR-15 can be point shot from a compressed high tuck position. Effective range is 25 yards. Although popular, friction locking throw lever mounts don't offer any practical advantage. Thumbscrew mounts can be removed in seconds.
Armalite thumbscrew mounts and LaRue throw lever mounts have a proven track record of Returning To Zero (RTZ) upon remount. Before lock down, push the mount toward the muzzle until its recoil lug mates with the receiver's cross slot. This prevents zero loss. Quick Release mounts are specified to RTZ within 0.5 MOA but usually do much better, using the forward push technique. A nail varnish witness mark may assist mounting into a consistent cross slot.
A scope mount's primary function is to retain zero under recoil and shock. Friction lock systems will withstand 5.56x45 recoil but thumbscrews have the advantage of torque, in resisting more energetic cartridges such as 7.62x51. Unless incapacitated, hand tightening of the thumbscrews is sufficient. Slots facilitate the use of a coin for extra leverage.
The Armalite scope mount satisfied all of the stipulations above, except its centerline height of 1.25" was too low to clear a BUIS. Particularly
for 30mm tubed scopes. Armalite recently addressed this by releasing a "high" variant of 1.45" centerline. Combining the high mount variants and
the KAC Micro BUIS should prevent BUIS ocular conflict. Armalite designed daylight between mount and ring caps for extra grip. Don't crush your
scope tube trying to close the gap. Torque the ring caps to 15 inch/pounds. Torque the cross bolts to 40 inch/pounds.
4.2) Leopold QRW & PRW Rings:
Misalignment imparts less contact between the scope tube and ring, reducing grip. The optic may shift under recoil or impact and lose zero. The traditional approach was to mount the optic for fit and bring it to a gunsmith for lapping. Leupold developed a new ring design that adjusts to the scope tube.
The ring top is constructed from spring steel and snaps onto the tube achieving concentricity, grip and zero retention. PRW rings are designed for permanent mounting. Pictured above, QRW rings are designed for quick release and return to zero.
The capability to mount, remove or swap out rifle optics, dependent on the task, terrain or lighting, has been a holy grail for military, law enforcement and hunters. Early military quick release systems were compromised retrofits. Weaver bases were the first successful attempt at a standardized mount.
Incorporated on the military M4, picatinny bases (Mil-Std 1913) have a different and more comprehensive specification. Both systems are essentially a dovetail rail with mating slots for repeatable positioning. QRW rings started out as weaver pattern but migrated to picatinny a long time ago.
A picatinny ring is compatible with both picatinny and weaver bases. A weaver ring is weaver specific, due to its cross bolt thickness. When a firearm recoils backward, the ring's inertia induces forward walk. To eliminate walk, push the ring toward the muzzle, until it's cross bolt mates with the base lug, then torque the cross ring via it's lever. The QRW rings maintain a return to zero (RTZ) of under 0.5 MOA. If necessary, boost return to zero by torquing the cross bolts to 22 inch/pounds. Torque the ring cap fasteners to a max of 15 inch/pounds.
Many shooters are skeptical of quick release systems' ability to withstand recoil. There have been instances of friction locked systems working loose under 7.62x51 recoil. Tappet gas systems have a particularly harsh recoil impulse that can work things loose. However, by mounting QRW ring levers on the right, inertia will induce them to walk clockwise and tighten under recoil.
Indexing the levers at 12 o'clock, prevents gouging hands while working the action. Grasp the lever's hub, pull straight back from the ring base,
rotate the lever to the desired position and release. The QRW ring's durability and reliability is derived from its simplicity.
It's a conventional torque locked ring with a captive cross bolt and lever wrench. Other systems need to be adjusted for mount/base wear.
The QRW are simply torqued down.
4.3) Badger Max-50 Rings:
4.4) Leapers Accushot Rings:
Questions & Feedback.
Well, that's about it guys. I hope you found this guide useful. If you have any questions or feedback, feel free to contact me through the welcome page.
Ian ST John.
|Field Jacket||Rifle Optics|
|Field Boots||Night Vision|
|Survival Knife||Dual Sports|
|Survival Kit||Dive Watches|
|Copyright © 2012|