The SIG Sauer SIG516 is an assault rifle manufactured by

SIG Sauer SIG Sauer is since the 1970s a combined brand name of several Firearms manufacturing companies, with SIG referring to ''Swiss Industry Group'' originally founded 1853, while the latter part comes from Sauer & Sohn, founded in 1751 in Germany a ...

, chambered in 5.56×45mm NATO.

History

The SIG Sauer SIG516 shares lineage with the Heckler & Koch HK416. The principal firearms engineers for the SIG516 were Robert Hirt and Chris Sirois. Following his time with Heckler & Koch, Hirt was recruited by

to work with then SIG engineer Chris Sirois on an improved version of the HK416. The SIG516 omitted many proprietary HK416 components that were exchanged for standard (

M4 carbine The M4 carbine (officially Carbine, Caliber 5.56 mm, M4) is a 5.56×45mm NATO assault rifle developed in the United States during the 1980s. It is a shortened version of the M16A2 assault rifle. The M4 is extensively used by the US mi ...

mil spec conform) components. Other HK416 issues like the (at the time) high cyclic rate, which causes lower life cycle, a gas vent, which showed up in low light conditions, and safety issues (i.e. the need for a firing pin safety) were also addressed. Hirt and Sirois later designed the SIG716 and SIG MCX/ SIG MPX. They were later recruited by

Caracal The caracal (''Caracal caracal'') () is a medium-sized Felidae, wild cat native to Africa, the Middle East, Central Asia, and arid areas of Pakistan and northwestern India. It is characterised by a robust build, long legs, a short face, long ...

to develop the CAR 816 series.

Design details

Operating mechanism

The SIG516 is a multi-caliber assault rifle capable of selective fire. It fires from a

closed bolt A semi or full-automatic firearm which is said to fire from a closed bolt or closed breech is one where, when ready to fire, a round is in the chamber and the bolt and working parts are forward ''in battery''. When the trigger is pulled, the ...

, and it has a short-stroke push rod piston system. The gas piston pushes the bolt carrier rearward where it is returned to the forward and locked position by a spring. This process loads the next cartridge. The 516 has a four-position gas regulator, allowing the user to choose the amount of gas directed to the piston, to adjust the gas system to function reliably with various propellant, projectile, fouling, operating environment, and configuration-specific pressure behavior.

Features

The SIG516 is based on the AR-15 platform ergonomic architecture, but it uses a short-stroke gas piston operating system (unlike the AR-15's piston-operated gas impingement system). The SIG516 uses a proprietary bolt carrier and government (law enforcement and military contract select-fire) rifles a special tungsten granules containing buffer to manage bolt carrier bounce and soften recoil. The barrel is chrome-lined. The amount of movement between the upper and lower receiver is minimized by a rubber wedge. The SIG516 has a safety lever on the left side to be used by the thumb of the shooting hand. The gas block integrates an adjustable gas regulator. The front gas block is railed to accept the front sight with a flip-up sight post. SIG516 models are equipped with an M16A2 style bird-cage flash hider. All SIG516 models except the Marksman are equipped with barrels shrouded by a free-floating M1913

Picatinny rail The 1913 rail (MIL-STD-1913 rail) is an American rail integration system designed by Richard Swan that provides a mounting platform for firearm accessories. It forms part of the NATO standard STANAG 2324 rail. It was originally used for mount ...

, as well as flip-up iron sights ( BUIS) made by SIG Sauer. The 5.56×45mm NATO SIG516 models accept

STANAG In NATO, a standardization agreement (STANAG, redundantly: STANAG agreement) defines processes, procedures, terms, and conditions for common military or technical procedures or equipment between the member countries of the alliance. Each NATO st ...

box magazine A magazine, often simply called a mag, is an ammunition storage and feeding device for a repeating firearm, either integral within the gun (internal/fixed magazine) or externally attached (detachable magazine). The magazine functions by holdi ...

s. These magazines are constructed in 5-, 10-, 20-, and 30-round variants. SIG516 Russian rifles use a different magazine as they are chambered in 7.62×39mm. The SIG516 Russian uses magazines designed for 7.62×39mm AR-15 style rifles. The rifle is hammer-fired and has a two-stage trigger mechanism in the SIG516 Marksman while all others have a military specification single-stage trigger. It is built to pass the

NATO The North Atlantic Treaty Organization (NATO ; , OTAN), also called the North Atlantic Alliance, is an intergovernmental organization, intergovernmental Transnationalism, transnational military alliance of 32 Member states of NATO, member s ...

test protocol “Over the Beach”, meaning the SIG516 is designed to fire safely as quickly as possible after being submerged in water.

Variants

SIG516 Precision Marksman

The SIG516 Precision Marksman has a longer barrel and an adjustable stock. It weighs and has a length of . The barrel is chrome-lined. Iron and or optical sights are installed on an integral MIL-STD-1913 Picatinny rail on the top of the receiver and additional accessories can be mounted on the fore end quad rails.

SIG716

The SIG716 is a

battle rifle A battle rifle is a service rifle chambered to fire a fully powered cartridge. The term "battle rifle" is a retronym created largely out of a need to differentiate automatic rifles chambered for fully powered cartridges from automatic rifles cha ...

variant, which is based on the same design, but is chambered for the larger 7.62x51mm NATO round and uses SR-25 pattern magazines.

SIG716 G2

The SIG716 G2 (Generation 2) variant features a short-stroke pushrod gas system. This operating system reduces carbon fouling, excessive heat and unburned powder in the action, ensuring further improved reliability and function. The G2 Patrol model is chambered in 7.62×51mm NATO, while the G2 DMR model is chambered in 6.5mm Creedmoor.

SIG 716i

The 716i (impingement) variant features a gas-operated, rotating bolt (internal piston) system instead of short-stroke pushrod gas system. This Stoner bolt and carrier piston operating system has helped SIG Sauer to bring down the cost of manufacturing and pushing more sales of 716i, whilst also achieving a weight reduction. The 716i is chambered in 7.62×51mm NATO. Sig Sauer appears to have discontinued SIG716 and SIG716 G2 models, since the company stopped displaying these products in their website, while they continue to sell magazines and spare parts in their online store. The 716i has been recognized as the best AR-10 rifle for the year 2020, by readers' choice voting of Ballistic magazine.

Users

* : Used by

law enforcement Law enforcement is the activity of some members of the government or other social institutions who act in an organized manner to enforce the law by investigating, deterring, rehabilitating, or punishing people who violate the rules and norms gove ...

* : Used by Canadian Special Operations Forces Command * : Used by Navy El-Sa'ka Forces * : In use with the Georgian MIA and MOD special forces * : Used by the

Hong Kong Police Force The Hong Kong Police Force (HKPF) is the primary law enforcement, investigative agency, and largest Hong Kong Disciplined Services, disciplined service under the Security Bureau (Hong Kong), Security Bureau of Hong Kong. Pursuant to the one c ...

including the

Special Duties Unit The Special Duties Unit (SDU; zh, c=特別任務連), nicknamed the "Flying Tigers" ( zh, c=飛虎隊), is the elite tactical unit of the Hong Kong Police Force tasked with countering terrorist attacks, hostage rescue, underwater search and r ...

and the Counter Terrorism Response Unit * : Order placed for 72,400 units of SIG 716i model. In December 2019, the first lot of 10,000 rifles was delivered to the Indian Army’s Northern Command. SIG Sauer also confirmed that delivery of the first order has already been completed. Another batch of 70,000 rifles was cleared for order in December 2023. The deal for an order of 73,000 rifles (that was cleared in 2023) was signed on 26 August 2024. Production of the latter 73,000 units order to be executed in India along with Nibe Group,

Pune Pune ( ; , ISO 15919, ISO: ), previously spelled in English as Poona (List of renamed Indian cities and states#Maharashtra, the official name until 1978), is a city in the state of Maharashtra in the Deccan Plateau, Deccan plateau in Western ...

with complete rifle manufacturing in India from 2025. **

Indian Army The Indian Army (IA) (ISO 15919, ISO: ) is the Land warfare, land-based branch and largest component of the Indian Armed Forces. The President of India is the Commander-in-Chief, Supreme Commander of the Indian Army, and its professional head ...

: 66,400 units in service, 73,000 on order **

Indian Air Force The Indian Air Force (IAF) (ISO 15919, ISO: ) is the air force, air arm of the Indian Armed Forces. Its primary mission is to secure Indian airspace and to conduct aerial warfare during armed conflicts. It was officially established on 8 Octob ...

: 4,000 in service **

Indian Navy The Indian Navy (IN) (ISO 15919, ISO: ) is the Navy, maritime and Amphibious warfare, amphibious branch of the Indian Armed Forces. The President of India is the Supreme Commander of the Indian Navy. The Chief of the Naval Staff (India), Chief ...

: 2,000 in service *: Used by the Mobile Brigade of the

Indonesian National Police The Indonesian National Police (, abbreviated as POLRI) is the national law enforcement and police force of the Republic of Indonesia. Founded on 1 July 1946, it was formerly a part of the Indonesian National Armed Forces, country's military si ...

, while the SIG716 G2 used by

Indonesian National Armed Forces The Indonesian National Armed Forces (; abbreviated as TNI) are the military forces of the Republic of Indonesia. It consists of the Indonesian Army, Army (''TNI-AD''), Indonesian Navy, Navy (''TNI-AL''), and Indonesian Air Force, Air Force ('' ...

special forces unit. * : Transitioning into the general service rifle of the Naval Infantry Force * :

Philippine Army The Philippine Army (PA) () is the main, oldest and largest branch of the Armed Forces of the Philippines (AFP), responsible for ground warfare. , it had an estimated strength of 143,100 soldiers The service branch was established on December ...

with 832 ordered from SIG Sauer as part of the Designated Marksman Rifle acquisition project under the Horizon 1 phase project. Expected to replace the M14. * : SIG516 and SIG716 variants used by Subunidad de Acciones Tácticas of Peruvian Police * : Used by PTJ (Counter-Terrorist Unit) of Serbian Police * : Used by the Mobilen Einsatzpolizei of the Aargau Police * : Used by the Naval Special Warfare Command (Thailand) * : Used by the

Trinidad and Tobago Police Service The Trinidad and Tobago Police Service or TTPS is the primary law enforcement agency of Trinidad and Tobago. It has been in operation for over 200 years. The Trinidad and Tobago Police Service (TTPS) is the national law enforcement agency of Trin ...

* : Used by Police Special Operation Department and Police Counter Attack Teams * : Used by the SBU and GUR * : Used by Metropolitan Police Counter Terrorist Specialist Firearms Officers (CTSFO) Surrey Police and

West Midlands Police West Midlands Police is the territorial police force responsible for policing the metropolitan county of West Midlands (county), West Midlands in England. The force covers an area of with 2.93million inhabitants, which includes the cities of ...

**: (British Overseas Territory) Used by Royal Cayman Islands Police Service Firearms Response Unit and by Cayman Islands Regiment. * : Used by

Florida Highway Patrol The Florida Highway Patrol (FHP) is a division of the Florida Department of Highway Safety and Motor Vehicles. It is Florida's highway patrol, highway State Police (United States), patrol and is the primary law enforcement agency charged with in ...

when purchased in 2019,

Delaware State Police The Delaware State Police (DSP) is a division of the Delaware Department of Public Safety and Homeland Security and is responsible for traffic regulation and law enforcement across the US State of Delaware, especially in areas underserved by loc ...

when purchased in 2012, and also by

Cincinnati Police Department The Cincinnati Police Department is the primary law enforcement agency of Cincinnati, Ohio. The department has 1,053 sworn police officer, officers and 119 non-sworn employees. History When Cincinnati incorporated as a village in 1802, a ...

SWAT, as well as the

Anderson County, South Carolina Anderson County is a county located in the U.S. state of South Carolina. As of the 2020 census, its population was 203,718. Its county seat is Anderson. Named for Revolutionary War leader Robert Anderson, the county is located in northwest ...

Sheriff's Office SWAT, and San Diego Police Department SWAT, in which the rifles will replace aging Vietnam-era M16s.

References

External links

716i TREAD
at sigsauer.com

at sigsauer.com
SIG-Sauer 516
at modernfirearms.net
SIG-Sauer 716
at modernfirearms.net {{ArmaLite AR-10 derivatives, state=collapsed 5.56×45mm NATO assault rifles 7.62×39mm assault rifles 7.62×51mm NATO battle rifles SIG Sauer rifles Assault rifles of the United States Semi-automatic rifles of the United States ArmaLite AR-10 derivatives AR-15 style rifles Gas-operated firearms Short stroke piston firearms Weapons and ammunition introduced in 2010