The SIG MCX is a family of

firearm A firearm is any type of gun designed to be readily carried and used by an individual. The term is legally defined further in different countries (see Legal definitions). The first firearms originated in 10th-century China, when bamboo tubes ...

s designed and manufactured by

SIG Sauer Several brother companies that design and manufacture firearms use the brand name SIG Sauer . The original company, ''Schweizerische Waggon-Fabrik'' (SWF), later ''Schweizerische Industrie-Gesellschaft'' (SIG), went through several selloffs, ...

, produced in both

selective fire Selective fire is the capability of a weapon to be adjusted to fire in semi-automatic, fully automatic, and/or burst mode. The modes are chosen by means of a selector switch, which varies depending on the weapon's design. Some selective-fire we ...

and semi-automatic only models, and features a short-stroke gas piston system, which is inherited from the earlier

SIG MPX The SIG MPX is a gas-operated submachine gun designed and manufactured by SIG Sauer, and is primarily chambered in 9×19mm Parabellum cartridge. It is a gas-operated firearm featuring a closed, rotating bolt. These design features, rare in submac ...

submachine gun A submachine gun (SMG) is a magazine-fed, automatic carbine designed to fire handgun cartridges. The term "submachine gun" was coined by John T. Thompson, the inventor of the Thompson submachine gun, to describe its design concept as an autom ...

. The MCX is available in

rifle A rifle is a long-barreled firearm designed for accurate shooting, with a barrel that has a helical pattern of grooves ( rifling) cut into the bore wall. In keeping with their focus on accuracy, rifles are typically designed to be held with ...

carbine A carbine ( or ) is a long gun that has a barrel shortened from its original length. Most modern carbines are rifles that are compact versions of a longer rifle or are rifles chambered for less powerful cartridges. The smaller size and lighter ...

short-barreled rifle Short-barreled rifle broadly refers to any rifle with an unusually short barrel. The term carbine describes a production rifle with a reduced barrel length for easier handling in confined spaces. Concern about concealment for illegal purposes ha ...

, and

pistol A pistol is a handgun, more specifically one with the chamber integral to its gun barrel, though in common usage the two terms are often used interchangeably. The English word was introduced in , when early handguns were produced in Europe, an ...

configurations (the latter configuration generally conforming to the definition of a compact

but for taking a

pistol brace A gunstock or often simply stock, the back portion of which is also known as a shoulder stock, a buttstock or simply a butt, is a part of a long gun that provides structural support, to which the barrel, action, and firing mechanism are attached. ...

rather than a

buttstock A gunstock or often simply stock, the back portion of which is also known as a shoulder stock, a buttstock or simply a butt, is a part of a long gun that provides structural support, to which the barrel, action, and firing mechanism are attached ...

). The rifle was further developed into the

SIG MCX Spear The SIG MCX-SPEAR is a multi-caliber rifle developed by the American division of SIG Sauer from the SIG MCX series of carbines. The SIG MCX-SPEAR is primarily chambered in .277 SIG FURY and can be adapted to 7.62×51mm NATO and 6.5mm Creedmoor wit ...

, which was adopted in its

.277 Fury The .277 Fury or 6.8×51mm Common Cartridge, (designated as the .277 SIG Fury by the SAAMI) is a centerfire rimless bottlenecked rifle cartridge announced by SIG Sauer in late 2019. Its hybrid three-piece cartridge case has a steel case head an ...

chambering as the

XM5 The XM5 is the U.S. Army variant of the SIG MCX Spear, a .277 Fury, 6.8×51mm (.277 in), gas-operated reloading, gas-operated, magazine (firearms), magazine-fed, assault rifle designed by SIG Sauer for the Next Generation Squad Weapon Program in ...

by the

U.S. Army The United States Army (USA) is the land service branch of the United States Armed Forces. It is one of the eight U.S. uniformed services, and is designated as the Army of the United States in the U.S. Constitution.Article II, section 2, cl ...

in 2022.

History

The SIG MCX was first introduced at

SHOT Show The SHOT Show , which is an acronym for "Shooting, Hunting and Outdoor Trade Show", is an American annual trade show for the shooting sports, hunting, outdoor recreations and firearm manufacturing industries. The show is owned and sponsored by ...

2015. The rifle was originally designed by SIG USA, the subsidiary of SIG Sauer based in

New Hampshire New Hampshire is a U.S. state, state in the New England region of the northeastern United States. It is bordered by Massachusetts to the south, Vermont to the west, Maine and the Gulf of Maine to the east, and the Canadian province of Quebec t ...

. In 2016, SIG recalled some of the rifles that had the first-generation bolt carrier group. A SIG MCX was used in the 2016

Orlando nightclub shooting On , 2016, Omar Mateen, a 29-year-old man, killed 49 people and wounded 53 more in a mass shooting at Pulse, a gay nightclub in Orlando, Florida, United States. Orlando Police officers shot and killed him after a three-hour standoff. In a 9- ...

, which at the time was the deadliest mass shooting in U.S. history, now second to the

2017 Las Vegas shooting On October 1, 2017, Stephen Paddock, a 64-year-old man from Mesquite, Nevada, opened fire on the crowd attending the Route 91 Harvest music festival on the Las Vegas Strip in . From his 32nd-floor suites in the Mandalay Bay hotel, he fired ...

Design

The SIG MCX series features a short-stroke gas piston system to reduce recoil and improve the reliability of the weapon; this was based on the design of the earlier

. The MCX features a system that allows for conversion between 5.56×45mm NATO,

.300 AAC Blackout The .300 AAC Blackout (designated as the 300 BLK by the SAAMI and 300 AAC Blackout by the C.I.P. or 300 AAC Blackout'' C.I.P. TDCC sheet 300 ACC Blackout/ref>), also known as 7.62×35mm, is an intermediate cartridge developed in the United Sta ...

, and

7.62×39mm The 7.62×39mm (aka 7.62 Soviet, formerly .30 Russian Short) round is a rimless bottlenecked intermediate cartridge of Soviet origin. The cartridge is widely used due to the worldwide proliferation of Russian SKS and AK-47 pattern rifles, as ...

ammunition, using standard 5.56 mm STANAG magazines for 5.56×45mm NATO and .300 AAC Blackout, and specially designed STANAG-compatible magazines for 7.62×39mm. The MCX is designed to deliver optimal performance with .300 AAC Blackout and an optional

suppressor A silencer, also known as a sound suppressor, suppressor, or sound moderator, is a muzzle device that reduces the acoustic intensity Sound intensity, also known as acoustic intensity, is defined as the power carried by sound waves per unit ...

. The barrel's profile is tapered at the crown to allow the installation of muzzle devices and direct-thread sound suppressors without the use of washers that degrade performance and allows the devices to self-center on installation. The barrel can be changed in a matter of seconds to another length or a different caliber. Additionally the barrels are nitride coated for corrosion resistance. It features hardened steel wear points. First generation MCX variants have a forend made of aluminum with a KeyMod system to add accessories while second generation MCX variants have an

M-LOK M-LOK, for Modular Lock, is a firearm rail interface system developed and patented by Magpul Industries. The license is free-of-charge, but subject to an approval process. M-LOK allows for direct accessory attachment onto the "negative s ...

handguard. Controls are mostly ambidextrous including the charging handle but not the bolt release. Sig produces four stock configurations are available for the MCX carbine. The overall layout of the two rifles is similar. SIG designed the upper receiver to be compatible with standard

AR-15 An AR-15-style rifle is any lightweight semi-automatic rifle based on the Colt AR-15 design. The original ArmaLite AR-15 is a scaled-down derivative of Eugene Stoner's ArmaLite AR-10 design. The then Fairchild Engine and Airplane Corporation d ...

and M16 lower receivers with the help of an adapter. An integrally suppressed upper receiver group based on the MCX was selected by

USSOCOM The United States Special Operations Command (USSOCOM or SOCOM) is the unified combatant command charged with overseeing the various special operations component commands of the Army, Marine Corps, Navy, and Air Force of the United States Ar ...

for the SURG (Suppressed Upper Receiver Group) contract in July 2018. These suppressed uppers would be paired with existing M4A1 lowers in SOCOM inventory.

Variants

SIG MCX

The SIG MCX is available with a

safe A safe (also called a strongbox or coffer) is a secure lockable box used for securing valuable objects against theft or fire. A safe is usually a hollow cuboid or cylinder, with one face being removable or hinged to form a door. The body and ...

/ semi-automatic

trigger group A trigger is a mechanism (engineering), mechanism that actuates the function of a ranged weapon such as a firearm, airgun, crossbow, or speargun. The word may also be used to describe a switch that initiates the operation of other non-shooting ...

for the U.S. civilian market, or safe/semi-automatic/

fully automatic An automatic firearm is an auto-loading firearm that continuously chambers and fires rounds when the trigger mechanism is actuated. The action of an automatic firearm is capable of harvesting the excess energy released from a previous discharge ...

trigger group for the

military A military, also known collectively as armed forces, is a heavily armed, highly organized force primarily intended for warfare. It is typically authorized and maintained by a sovereign state, with its members identifiable by their distinct ...

and

law enforcement agencies A law enforcement agency (LEA) is any government agency responsible for the enforcement of the laws. Jurisdiction LEAs which have their ability to apply their powers restricted in some way are said to operate within a jurisdiction. LEA ...

. SIG Sauer offers the rifle in semi-automatic only in three different configurations for the civilian market: * The SIG MCX PATROL is the standard configuration of the rifle with a 406 mm (16 in) barrel. * The SIG MCX SBR is a

configuration of the rifle with a 229 mm (9 in) barrel. (''Under U.S. federal law, rifles with barrels shorter than 16 inches are

Title II weapons Title II weapons, or NFA firearms, are designations of certain weapons under the United States National Firearms Act (NFA). These are weapons requiring a Type 01 Federal Firearms License (FFL) as well as a Class 3 Special Occupation Tax (SOT) t ...

, which are subject to federal restrictions, as well as being regulated by state laws''). * The SIG MCX Pistol is the

configuration of the rifle with a 229 mm (9 in) barrel or 292 mm (11.5 in) barrel and comes either with the SIG Sauer SBX (pistol stabilizing brace) or SIG Sauer PCB (pistol pivoting contour folding brace). (''This configuration fits the U.S. legal definition of a "handgun", in that it is only designed to be fired with a single point of contact with the shooter's body, though it is really a compact carbine rifle, as it fires an intermediate round. The BATFE previously warned users that shouldering a weapon fitted with the SIG SBX, or a similar forearm brace, and not registered as a short-barreled rifle, constitutes the making of a short-barreled rifle, which is a

Title II weapon Title II weapons, or NFA firearms, are designations of certain weapons under the United States National Firearms Act (NFA). These are weapons requiring a Type 01 Federal Firearms License (FFL) as well as a Class 3 Special Occupation Tax (SOT) t ...

. However, as of April 2017, this is no longer the case''). * The SIG MCX Low Visibility Assault Weapon (LVAW) is a short-barreled, suppressed, select-fire variant available only to military and law enforcement agencies. It is nicknamed the "

Black Mamba The black mamba (''Dendroaspis polylepis'') is a species of highly venomous snake belonging to the family Elapidae. It is native to parts of sub-Saharan Africa. First formally described by Albert Günther in 1864, it is the second-longest ...

SIG MCX VIRTUS

The SIG MCX VIRTUS is the second generation of the SIG MCX series and was introduced in 2017. * The SIG MCX VIRTUS Patrol is the standard configuration rifle that features a 406 mm (16 in) barrel, a 1:7 inch twist, a custom Sig Matchlite Duo Trigger for improved accuracy, a folding and collapsing 5-position stock, four handguard lengths to choose from, interchangeable barrels and a special internal recoil system. * The SIG MCX VIRTUS SBR is the short-barreled rifle configuration of the MCX VIRTUS. It features a 292 mm (11.5 in) barrel for the 5.56×45mm NATO caliber, and a 140 mm (5.5 in) barrel and 229 mm (9 in) barrel for the .300 AAC Blackout caliber. * The SIG MCX VIRTUS Pistol is the pistol configuration of the MCX VIRTUS which features an SBX stabilizer brace. It features an 292 mm (11.5 in) barrel for the 5.56×45mm NATO caliber, and a 229 mm (9 in) barrel for the .300 AAC Blackout caliber.

SIG MCX RATTLER

The SIG MCX RATTLER is a

variant chambered in

and 5.56. It is intended to serve as a

personal defense weapon Personal defense weapons (PDWs) are a class of firearms intended for self-defense and security rather than warfare and infantry. Most PDWs fire a small-caliber (less than ), centerfire bottleneck cartridge resembling a scaled-down intermediate ...

, featuring a barrel, and comes with a

Picatinny rail The Picatinny rail ( or ), or Pic rail for short, also known as a MIL-STD-1913 rail, 1913 rail or STANAG 2324 rail (cancelled), is a military standard rail interface system that provides a mounting platform for firearm accessories. It was o ...

tail interface for attaching either a compact

or a folding PCB (pistol contour brace). In February 2018,

ordered upper receiver group conversion kits for the MCX Rattler in .300BLK for evaluation. The MCX Rattler was later selected as the winner of SOCOM's Commercial Personal Defense Weapon (CPDW) contract in May 2022 and suppressed MCX Rattlers will be ordered in 5.56 and .300BLK.

SIG MCX-SPEAR LT

The SIG MCX-SPEAR LT is the third generation of the SIG MCX, introduced in 2022. Intended to serve as a

, it features a , or barrel and a

tail interface for attaching either a

or a pistol brace. It is available in 5.56 mm NATO,

.300 Blackout The .300 AAC Blackout (designated as the 300 BLK by the SAAMI and 300 AAC Blackout by the C.I.P. or 300 AAC Blackout'' C.I.P. TDCC sheet 300 ACC Blackout/ref>), also known as 7.62×35mm, is an intermediate cartridge developed in the United Stat ...

and 7.62x39mm.

Derivatives

SIG MCX-SPEAR

The

SIG MCX SPEAR The SIG MCX-SPEAR is a multi-caliber rifle developed by the American division of SIG Sauer from the SIG MCX series of carbines. The SIG MCX-SPEAR is primarily chambered in .277 SIG FURY and can be adapted to 7.62×51mm NATO and 6.5mm Creedmoor wit ...

was developed as Sig Sauer's submission for the

United States Army The United States Army (USA) is the land service branch of the United States Armed Forces. It is one of the eight U.S. uniformed services, and is designated as the Army of the United States in the U.S. Constitution.Article II, section 2, cla ...

Next Generation Squad Weapon (NGSW) program and is chambered in 6.8×51mm SIG Fury cartridge. Sig Sauer was chosen as the winner on 19 April 2022, designating the weapon the

in U.S. military service.

Users

* *: Announced September 2022, to be acquired in .300 Blackout * : DSU and the special response unit of the Ghent local police (COPS) *: Saskatchewan Conservation Officers. * : Used by the

K-Commando K-Commando (K-Komando) is a special unit of the Estonian Police and Border Guard Board ( Politsei- ja Piirivalveamet), created in the 1991. It is a special unit of the Estonian police force similar in function to the SWAT teams in the U.S., and is ...

* : Groupement de commandos de montagne, 27th Mountain Infantry Brigade, 5 in 2021, all rifles acquired in

. * : Berlin Police, 300 modified MCXs to meet the police's requirements were ordered in October 2017, plus an additional 160 units for the SEK of Berlin, Landespolizei of

Schleswig Holstein Schleswig-Holstein (; da, Slesvig-Holsten; nds, Sleswig-Holsteen; frr, Slaswik-Holstiinj) is the northernmost of the 16 states of Germany, comprising most of the historical duchy of Holstein and the southern part of the former Duchy of Schl ...

, 531 units ordered.

Rhineland-Palatinate Police The Rhineland-Palatinate State Police is the state police (''Landespolizei'') of the German federal state of Rhineland-Palatinate and numbers ca. 9,000 police officers. The five regional police authorities are headquartered in Koblenz, Trier, Mainz ...

: more than 100 rifles ordered in late 2019. * : Used by Shayetet 13, the

Israel Defense Forces The Israel Defense Forces (IDF; he, צְבָא הַהֲגָנָה לְיִשְׂרָאֵל , ), alternatively referred to by the Hebrew-language acronym (), is the national military of the Israel, State of Israel. It consists of three servic ...

Naval Commando unit. * : Used by the

Netherlands Maritime Special Operations Forces The Netherlands Maritime Special Operations Forces (NLMARSOF, also simply referred to as MARSOF) is the special forces unit of the Marine Corps of the Royal Netherlands Navy. It is one of the three principal units tasked with special operations ...

and the

Dienst Speciale Interventies The ''Dienst Speciale Interventies'' ( en, Special Intervention Service), commonly abbreviated DSI, is the elite police tactical unit of the Dutch National Police Corps and was formally established on 1 July 2006. The DSI is tasked with neutralisin ...

. All rifles acquired in

and fitted with the SIG Suppressed Upper Receiver. * : '' Jednostka Wojskowa Grom'' and ''

JW Formoza , (Military Unit Formoza) (2007-2011 ) (Naval Special Operations Unit), previous names: (Polish Navy Special Operations Sections), (Special Frogmen Groups). History JWF is now part of Wojska Specjalne (1975-2008 - part of the Polish Navy) ...

'' acquired the SIG MCX VIRTUS and MCX RATTLER in .300 AAC Blackout with conversion kits to 5.56×45mm NATO and

ammunition. * :

Polícia de Segurança Pública The Polícia de Segurança Pública MHTE (PSP; ''Public Security Police'') is the national civil police force of Portugal. Part of the Portuguese security forces, the mission of the PSP is to defend Republican democracy, safeguarding internal se ...

acquired SIG MCX in 5.56×45mm NATO used by

Special Operations Group (Portugal) The Special Operations Group ( pt, Grupo de Operações Especiais, GOE) is the police tactical unit of the Public Security Police (PSP), the national police force of Portugal. GOE was created in 1982 and has around 200 operatives. Although a pol ...

. * : Used by the SBU

Alpha Group Spetsgruppa "A", also known as Alpha Group (a popular English name), or Alfa, whose official name is Directorate "A" of the FSB Special Purpose Center (TsSN FSB) (Russian: Спецназ ФСБ "Альфа"), is an elite stand-alone sub-unit o ...

. * : Used by the

Police The police are a constituted body of persons empowered by a state, with the aim to enforce the law, to ensure the safety, health and possessions of citizens, and to prevent crime and civil disorder. Their lawful powers include arrest and t ...

Counter Terrorist Specialist Firearms Officers including the

Metropolitan Police Service The Metropolitan Police Service (MPS), formerly and still commonly known as the Metropolitan Police (and informally as the Met Police, the Met, Scotland Yard, or the Yard), is the territorial police force responsible for law enforcement and ...

and

UKSF The United Kingdom Special Forces (UKSF) is a directorate comprising the Special Air Service, the Special Boat Service, the Special Reconnaissance Regiment, the Special Forces Support Group, 18 (UKSF) Signal Regiment and the Joint Special Forces ...

to replace the HK MP5SD3s. * :

being acquired for all DoD branches. SIG MCX Rattler in .300BLK is being acquired for

forces. The LVAW (Low Visibility Assault Weapon), an MCX variant, was used by multiple SOCOM forces including

United States Navy SEALs The United States Navy Sea, Air, and Land (SEAL) Teams, commonly known as Navy SEALs, are the U.S. Navy's primary special operations force and a component of the Naval Special Warfare Command. Among the SEALs' main functions are conducting sma ...

Delta Force The 1st Special Forces Operational Detachment–Delta (1st SFOD-D), referred to variously as Delta Force, Combat Applications Group (CAG), Army Compartmented Elements (ACE), "The Unit", or within Joint Special Operations Command (JSOC), Task Fo ...

, and

Joint Special Operations Command The Joint Special Operations Command (JSOC) is a joint component command of the United States Special Operations Command (USSOCOM) and is charged with studying special operations requirements and techniques to ensure interoperability and equip ...

References

External links

* *
SIG MCX
on

's official website
sigsauer.com

Guide To The SIG Sauer MCX - The Firearm Blog
{{Personal defense weapons .300 BLK firearms 5.56 mm assault rifles 7.62×39mm semi-automatic rifles Semi-automatic rifles Short stroke piston firearms Weapons and ammunition introduced in 2015 ArmaLite AR-10 derivatives AR-15 style rifles Designated marksman rifles Carbines Personal defense weapons SIG Sauer rifles

History

Design

Variants

SIG MCX

SIG MCX VIRTUS

SIG MCX RATTLER

SIG MCX-SPEAR LT

Derivatives

SIG MCX-SPEAR

Users

See also

References

External links