Advanced Combat Optical Gunsight
Encyclopedia
Advanced Combat Optical Gunsights (abbreviated ACOG) are a series of telescopic sight
s manufactured by Trijicon
. The ACOG is designed to be used on the M16 rifle
and M4 carbine
, but Trijicon has developed ACOG accessories for certain other firearms. Models provide fixed power magnification
levels from 1.5x to 6x.
The ACOG's reticle is illuminated by an internal phosphor illuminated by the radioactive decay of tritium
. The tritium illumination has a usable life of 10-15 years. Some versions have an additional daytime reticle illumination via an external fiber optic
light pipe
.
and a crosshair reticle with a bullet drop compensator that allows the operator to engage targets out to 600 m (1,968.5 ft) without adjustments. Its reticle glows amber
in darkness. It also incorporates rudimentary ghost ring iron sight
s as a backup for targets that are within 50 m (164 ft), but it is only usable when mounted on the carrying handle. The TA31RCO has 4x magnification, no iron sights, and uses a red
chevron reticle which automatically adjusts to the ambient light conditions and has a bullet drop compensator that allows engagements at up to 800 m (2,624.7 ft). The M150 adds flip caps and is waterproof up to 11 m (36.1 ft). Most ACOGs do not use batteries, being designed to use daylight or internal phosphor illumination. Features on other ACOGs include Docter reflex sights mounted on top, Picatinny rail
s, and mounted Trijicon red dot sights.
Although the ACOG is designed for the Picatinny rail
of the M16A4
and M4
, it can be mounted on the carrying handles of previous models.
Trijicon later produced ACOG mounts and adapters for weapons besides the M16, including the Beretta AR70/90
series; SIG SG 550
, Heckler & Koch
, Bushmaster ACR, and FN SCAR
weapon systems; and the Steyr AUG
.
as a collimator sight
. As in any other collimator sight, the user does not actually look through the sight but instead keeps the collimated (infinity) image of the illuminated part of the reticle in focus with one eye while the other eye views the entire field of view
to acquire the target. In this both eyes open technique the brain superimposes the aiming reticle on the target. An added part of the technique is to shift focus after acquisition to the dominant eye/telescopic image for more accurate shooting. This overcomes the problem of centering or acquiring fast transversing targets common with all telescopic sights. Only certain models of the ACOG are designed with bright enough daylight lit fiber-optic or battery powered LED reticles to use this technique.
.: is used by all armed forces in Colombia.: Finnish Defense Forces.: GSG 9
Federal Police Special Forces: Iraqi Security Forces
: Israel Defense Forces
.: New Zealand Army
: Saudi Arabian Army
.: Spanish Army
, standard sight for the Heckler & Koch MG4
.: Turkish Army
: UAE Army.: British Army
and the Royal Marines
: United States armed forces
(see below), various law enforcement agencies.
and Marine Corps
both field the TA31RCO for the M4
and M16A4, designated the M150 in Army service and AN/PVQ-31 Rifle Combat Optic in the Marine Corps. The army type designated the M150 in December 2008. In October 2005, the USMC planned on having 115,000 ACOGs in inventory and according to Pendleton
News the ACOG is issued to "most" forward-deployed Marines. The TA01NSN is part of the SOPMOD
package for the M4A1 carbine
. Other Trijicon models have also seen service after being purchased at the unit level.
has been the subject of some criticism for inscribing references to Bible
verse addresses within the model numbers on their ACOG sights. Starting in late 2009, Trijicon began shipping sights to the U.S. military without the Bible verses.
Telescopic sight
A telescopic sight, commonly called a scope, is a sighting device that is based on an optical refracting telescope. They are equipped with some form of graphic image pattern mounted in an optically appropriate position in their optical system to give an accurate aiming point...
s manufactured by Trijicon
Trijicon
Trijicon ) is an American company, based in Wixom, Michigan, that manufactures and distributes optical sighting devices for firearms, including pistols, rifles, and shotguns....
. The ACOG is designed to be used on the M16 rifle
M16 rifle
The M16 is the United States military designation for the AR-15 rifle adapted for both semi-automatic and full-automatic fire. Colt purchased the rights to the AR-15 from ArmaLite, and currently uses that designation only for semi-automatic versions of the rifle. The M16 fires the 5.56×45mm NATO...
and M4 carbine
M4 carbine
The M4 carbine is a family of firearms tracing its lineage back to earlier carbine versions of the M16, all based on the original AR-15 designed by Eugene Stoner and made by ArmaLite. It is a shorter and lighter variant of the M16A2 assault rifle, with 80% parts commonality.It is a gas-operated,...
, but Trijicon has developed ACOG accessories for certain other firearms. Models provide fixed power magnification
Magnification
Magnification is the process of enlarging something only in appearance, not in physical size. This enlargement is quantified by a calculated number also called "magnification"...
levels from 1.5x to 6x.
The ACOG's reticle is illuminated by an internal phosphor illuminated by the radioactive decay of tritium
Tritium
Tritium is a radioactive isotope of hydrogen. The nucleus of tritium contains one proton and two neutrons, whereas the nucleus of protium contains one proton and no neutrons...
. The tritium illumination has a usable life of 10-15 years. Some versions have an additional daytime reticle illumination via an external fiber optic
Optical fiber
An optical fiber is a flexible, transparent fiber made of a pure glass not much wider than a human hair. It functions as a waveguide, or "light pipe", to transmit light between the two ends of the fiber. The field of applied science and engineering concerned with the design and application of...
light pipe
Light tube
Light tubes or light pipes are used for transporting or distributing natural or artificial light. In their application to daylighting, they are also often called sun pipes, sun scopes, solar light pipes, sky lights or daylight pipes.Generally speaking, a light pipe or light tube may refer to:* a...
.
Design details
The ACOG is available in a variety of configurations from the manufacturer with different reticles, illumination, and other features. The TA01NSN features 4x magnificationMagnification
Magnification is the process of enlarging something only in appearance, not in physical size. This enlargement is quantified by a calculated number also called "magnification"...
and a crosshair reticle with a bullet drop compensator that allows the operator to engage targets out to 600 m (1,968.5 ft) without adjustments. Its reticle glows amber
Amber (color)
Amber is an orange-yellow color that got its name from the material known as amber. Due to this, amber can refer not to one but to a series of shades of orange, since the natural material varies from nearly yellow when newer to orange or reddish-orange when older.-Amber:Amber is a pure chroma color...
in darkness. It also incorporates rudimentary ghost ring iron sight
Iron sight
Iron sights are a system of shaped alignment markers used as a sighting device to assist in the aiming of a device such as a firearm, crossbow, or telescope, and exclude the use of optics as in telescopic sights or reflector sights...
s as a backup for targets that are within 50 m (164 ft), but it is only usable when mounted on the carrying handle. The TA31RCO has 4x magnification, no iron sights, and uses a red
Red
Red is any of a number of similar colors evoked by light consisting predominantly of the longest wavelengths of light discernible by the human eye, in the wavelength range of roughly 630–740 nm. Longer wavelengths than this are called infrared , and cannot be seen by the naked eye...
chevron reticle which automatically adjusts to the ambient light conditions and has a bullet drop compensator that allows engagements at up to 800 m (2,624.7 ft). The M150 adds flip caps and is waterproof up to 11 m (36.1 ft). Most ACOGs do not use batteries, being designed to use daylight or internal phosphor illumination. Features on other ACOGs include Docter reflex sights mounted on top, Picatinny rail
Picatinny rail
The Picatinny rail or MIL-STD-1913 rail or STANAG 2324 rail or a "Tactical Rail" is a bracket used on some firearms in order to provide a standardized mounting platform. A similar system is the Weaver rail mount.-Description:...
s, and mounted Trijicon red dot sights.
Although the ACOG is designed for the Picatinny rail
Picatinny rail
The Picatinny rail or MIL-STD-1913 rail or STANAG 2324 rail or a "Tactical Rail" is a bracket used on some firearms in order to provide a standardized mounting platform. A similar system is the Weaver rail mount.-Description:...
of the M16A4
M16 rifle
The M16 is the United States military designation for the AR-15 rifle adapted for both semi-automatic and full-automatic fire. Colt purchased the rights to the AR-15 from ArmaLite, and currently uses that designation only for semi-automatic versions of the rifle. The M16 fires the 5.56×45mm NATO...
and M4
M4 carbine
The M4 carbine is a family of firearms tracing its lineage back to earlier carbine versions of the M16, all based on the original AR-15 designed by Eugene Stoner and made by ArmaLite. It is a shorter and lighter variant of the M16A2 assault rifle, with 80% parts commonality.It is a gas-operated,...
, it can be mounted on the carrying handles of previous models.
Trijicon later produced ACOG mounts and adapters for weapons besides the M16, including the Beretta AR70/90
Beretta AR70/90
The Beretta AR70/90 is a gas operated self loading assault rifle chambered for the 5.56mm cartridge, and is the standard issue service rifle of the Italian Armed Forces. The weapon also features grenade sights, and is designed to be fitted with a rifle grenade...
series; SIG SG 550
SIG SG 550
The SG 550 is an assault rifle manufactured by Swiss Arms AG of Neuhausen, Switzerland...
, Heckler & Koch
Heckler & Koch
Heckler & Koch GmbH is a German defense manufacturing company that produces various small arms. Some of their products include the SA80, MP5 submachine gun, G3 automatic rifle, the G36 assault rifle, the HK 416, the MP7 personal defense weapon, the USP series of handguns, and the high-precision...
, Bushmaster ACR, and FN SCAR
FN SCAR
The Special Operations Forces Combat Assault Rifle, or SCAR, is a modular rifle made by FN Herstal for the United States Special Operations Command to satisfy the requirements of the SCAR competition. This family of rifles consist of two main types...
weapon systems; and the Steyr AUG
Steyr AUG
The AUG is an Austrian bullpup 5.56mm assault rifle, designed in the early 1970s by Steyr Mannlicher GmbH & Co KG . The AUG was adopted by the Austrian Army as the StG 77 in 1977, where it replaced the 7.62mm StG 58 automatic rifle...
.
Bindon aiming concept
Several ACOG models are designed to be used with the "Bindon Aiming Concept", an aiming technique developed by Trijicon founder and optical designer Gly Bindon. The technique is essentially using the illuminated part of the reticle and its focusing rear eyepieceEyepiece
An eyepiece, or ocular lens, is a type of lens that is attached to a variety of optical devices such as telescopes and microscopes. It is so named because it is usually the lens that is closest to the eye when someone looks through the device. The objective lens or mirror collects light and brings...
as a collimator sight
Collimator sight
A collimator sight is a type of optical sight that allows the user looking into it to see an illuminated aiming point aligned with the device the sight is attached to regardless of eye position...
. As in any other collimator sight, the user does not actually look through the sight but instead keeps the collimated (infinity) image of the illuminated part of the reticle in focus with one eye while the other eye views the entire field of view
Field of view
The field of view is the extent of the observable world that is seen at any given moment....
to acquire the target. In this both eyes open technique the brain superimposes the aiming reticle on the target. An added part of the technique is to shift focus after acquisition to the dominant eye/telescopic image for more accurate shooting. This overcomes the problem of centering or acquiring fast transversing targets common with all telescopic sights. Only certain models of the ACOG are designed with bright enough daylight lit fiber-optic or battery powered LED reticles to use this technique.
Users
:GEOF (Grupo Especial de Operaciones Federales), Grupo Halcón.: Australian ArmyAustralian Army
The Australian Army is Australia's military land force. It is part of the Australian Defence Force along with the Royal Australian Navy and the Royal Australian Air Force. While the Chief of Defence commands the Australian Defence Force , the Army is commanded by the Chief of Army...
.: is used by all armed forces in Colombia.: Finnish Defense Forces.: GSG 9
GSG 9
The GSG 9 der Bundespolizei , is the elite counter-terrorism and special operations unit of the German Federal Police.-History and name:...
Federal Police Special Forces: Iraqi Security Forces
Iraqi Security Forces
The Iraqi Armed Forces are the military forces of the Government of Iraq. They consist of the Iraqi Army, the Iraqi Air Force, and the Iraqi Navy....
: Israel Defense Forces
Israel Defense Forces
The Israel Defense Forces , commonly known in Israel by the Hebrew acronym Tzahal , are the military forces of the State of Israel. They consist of the ground forces, air force and navy. It is the sole military wing of the Israeli security forces, and has no civilian jurisdiction within Israel...
.: New Zealand Army
New Zealand Army
The New Zealand Army , is the land component of the New Zealand Defence Force and comprises around 4,500 Regular Force personnel, 2,000 Territorial Force personnel and 500 civilians. Formerly the New Zealand Military Forces, the current name was adopted around 1946...
: Saudi Arabian Army
Saudi Arabian Army
The Saudi Arabian Army , also called Royal Saudi Land Force . Is a branch of the Saudi Armed Forces. The total number of active troops is estimated to be 233,500The current Chief of the Saudi General Staff is Field Marshal Saleh Al-Muhaya....
.: Spanish Army
Spanish Army
The Spanish Army is the terrestrial army of the Spanish Armed Forces responsible for land-based military operations. It is one of the oldest active armies - dating back to the 15th century.-Introduction:...
, standard sight for the Heckler & Koch MG4
Heckler & Koch MG4
The MG4 is a belt-fed 5.56 mm light machine gun designed and developed by the German company Heckler & Koch. The weapon was developed in the late 1990s and was first seen publicly in September 2001. It has been selected to replace the 7.62 mm MG3 general-purpose machine gun in the Bundeswehr at the...
.: Turkish Army
Turkish Army
The Turkish Army or Turkish Land Forces is the main branch of the Turkish Armed Forces responsible for land-based military operations. The modern history of the army began with its formation after the collapse of the Ottoman Empire...
: UAE Army.: British Army
British Army
The British Army is the land warfare branch of Her Majesty's Armed Forces in the United Kingdom. It came into being with the unification of the Kingdom of England and Scotland into the Kingdom of Great Britain in 1707. The new British Army incorporated Regiments that had already existed in England...
and the Royal Marines
Royal Marines
The Corps of Her Majesty's Royal Marines, commonly just referred to as the Royal Marines , are the marine corps and amphibious infantry of the United Kingdom and, along with the Royal Navy and Royal Fleet Auxiliary, form the Naval Service...
: United States armed forces
United States armed forces
The United States Armed Forces are the military forces of the United States. They consist of the Army, Navy, Marine Corps, Air Force, and Coast Guard.The United States has a strong tradition of civilian control of the military...
(see below), various law enforcement agencies.
Use by U.S. military
The United States ArmyUnited States Army
The United States Army is the main branch of the United States Armed Forces responsible for land-based military operations. It is the largest and oldest established branch of the U.S. military, and is one of seven U.S. uniformed services...
and Marine Corps
United States Marine Corps
The United States Marine Corps is a branch of the United States Armed Forces responsible for providing power projection from the sea, using the mobility of the United States Navy to deliver combined-arms task forces rapidly. It is one of seven uniformed services of the United States...
both field the TA31RCO for the M4
M4
- Computers :* m4 , a macro processing language* GNU m4, the GNU version of the m4 language* M4 Solutions, a software suite displaying telecommunications data in a geographic view, developed by Mapcom Systems- Firearms and military equipment :...
and M16A4, designated the M150 in Army service and AN/PVQ-31 Rifle Combat Optic in the Marine Corps. The army type designated the M150 in December 2008. In October 2005, the USMC planned on having 115,000 ACOGs in inventory and according to Pendleton
Marine Corps Base Camp Pendleton
Marine Corps Base Camp Pendleton is the major West Coast base of the United States Marine Corps and serves as its prime amphibious training base...
News the ACOG is issued to "most" forward-deployed Marines. The TA01NSN is part of the SOPMOD
SOPMOD
The Special Operations Peculiar MODification kit is an accessory system for the M4A1 carbine and FN SCAR Mk 16/17 used by USSOCOM...
package for the M4A1 carbine
M4 carbine
The M4 carbine is a family of firearms tracing its lineage back to earlier carbine versions of the M16, all based on the original AR-15 designed by Eugene Stoner and made by ArmaLite. It is a shorter and lighter variant of the M16A2 assault rifle, with 80% parts commonality.It is a gas-operated,...
. Other Trijicon models have also seen service after being purchased at the unit level.
Controversy
TrijiconTrijicon
Trijicon ) is an American company, based in Wixom, Michigan, that manufactures and distributes optical sighting devices for firearms, including pistols, rifles, and shotguns....
has been the subject of some criticism for inscribing references to Bible
Bible
The Bible refers to any one of the collections of the primary religious texts of Judaism and Christianity. There is no common version of the Bible, as the individual books , their contents and their order vary among denominations...
verse addresses within the model numbers on their ACOG sights. Starting in late 2009, Trijicon began shipping sights to the U.S. military without the Bible verses.