SIG MCX#SIG MCX-SPEAR

The SIG MCX was introduced at SHOT Show 2015. The rifle was originally designed by SIG USA, the subsidiary of SIG Sauer based in New Hampshire. In 2016, SIG recalled some of the rifles that had the first-generation bolt carrier group.{{cite web|url=https://sofrep.com/70713/sig-sauer-mcx-mandatory-recall/|title=Sig Sauer MCX Mandatory Recall|date=24 December 2014|website=SOFREP News}} It has been used by various SWAT teams and militaries, including the Ukrainian Armed Forces during the Russian Invasion of Ukraine. A SIG MCX was used in the 2016 Orlando nightclub shooting, which was the deadliest mass shooting in U.S. history, until exceeded by the 2017 Las Vegas shooting.{{Cite news|url=https://www.washingtonpost.com/news/checkpoint/wp/2016/06/14/the-gun-the-orlando-shooter-used-was-not-an-ar-15-that-doesnt-change-much/|title=The gun the Orlando shooter used was a Sig Sauer MCX, not an AR-15. That doesn't change much.|last=Gibbons-Neff|first=Thomas|newspaper=The Washington Post|location=Washington, D.C.|access-date=2017-07-23}}

The SIG MCX series features a short-stroke gas piston{{cite web|url=https://www.thefirearmblog.com/blog/2022/04/30/mcx-virtus-piston/|title=SILENCER SATURDAY #226: The MCX Virtus Piston System|website=The Firearm Blog|date=April 30, 2022|access-date=April 30, 2022}} with dual recoil spring system to reduce recoil and improve the reliability of the weapon;{{cite web|url=https://nationalinterest.org/blog/buzz/sig-sauer-mcx-virtus-patrol-better-ar-15-198313|title=Is the Sig Sauer MCX Virtus Patrol Better Than an AR-15?|website=The National Interest|date=December 21, 2021|access-date=December 21, 2021}} this was based on the design of the earlier SIG MPX.{{cite web|title=First Look: SIG Sauer MCX |website=Guns & Ammo |url=http://www.gunsandammo.com/first-look/sig-sauer-mcx/ |archive-url=https://web.archive.org/web/20190224001742/http://www.gunsandammo.com/editorial/sig-sauer-mcx/249535 |archive-date= 24 February 2019 |date=January 13, 2015}} The MCX features a system that enables conversion between 5.56×45mm NATO, .300 AAC Blackout, and 7.62×39mm 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.{{cite news|url=https://www.americanrifleman.org/articles/2015/1/20/sig-sauer-mcx-carbine/|title=SIG Sauer MCX Carbine|website=American Rifleman}}

The barrel's profile is tapered at the crown to enable the installation of muzzle devices and direct-thread sound suppressors without the use of washers that degrade performance and enables 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.{{cite web|url=http://www.recoilweb.com/recoil-exclusive-breakdown-of-the-sig-mcx-56367.html|first=David|last=Merrill|publisher=Recoil|title=RECOIL Exclusive: Breakdown of the Sig MCX|date=16 January 2015}}{{cite web|title=Full Review: SIG Sauer MCX|first=Drew|last=Warden|date=October 7, 2015|url=http://www.gundigest.com/tactical-gear/full-review-sig-sauer-mcx|publisher=Gun Digest}} 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 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.{{cite web|url=http://www.tactical-life.com/firearms/review-sig-sauer-mcx/#mcx-twa15-lead|title=Sig Sauer's MCX Rifle: An Elite Modular Weapons System|date=30 June 2015|first=Sean|last=Utley|publisher=Tactical Life|access-date=25 August 2016|archive-date=14 October 2016|archive-url=https://web.archive.org/web/20161014031542/http://www.tactical-life.com/firearms/review-sig-sauer-mcx/#mcx-twa15-lead|url-status=dead}} SIG designed the upper receiver to be compatible with standard AR-15 and M16 lower receivers with the help of an adapter.{{Cite web|url=http://soldiersystems.net/2015/02/09/ar-lower-receiver-extension-adapter-for-sig-mcx-upper/|title=AR Lower Receiver Extension Adapter for SIG MCX Upper - Soldier Systems Daily|date=9 February 2015 |access-date=2017-06-10}}

An integrally suppressed upper receiver group based on the MCX was selected by USSOCOM for the SURG (Suppressed Upper Receiver Group) contract in July 2018. These suppressed uppers would be paired with existing M4A1 lowers in SOCOM inventory.{{cite web |title=USSOCOM Awards SIG SAUER $48 Mil for Suppressed Upper Receiver Group |url=https://soldiersystems.net/2018/07/29/ussocom-awards-sig-sauer-48-mil-for-suppressed-upper-receiver-group/ |website=Soldier Systems Daily |access-date=24 May 2022 |archive-url=https://web.archive.org/web/20210419063506/https://soldiersystems.net/2018/07/29/ussocom-awards-sig-sauer-48-mil-for-suppressed-upper-receiver-group/ |archive-date=19 April 2021 |date=29 July 2018}}{{cite web |title=First Look – USSOCOM's New Suppressed Upper Receiver Group (SURG) from SIG SAUER |url=https://soldiersystems.net/2018/08/02/first-look-socoms-new-suppressed-upper-receiver-group-from-sig-sauer/ |website=Soldier System Daily |access-date=24 May 2022 |archive-url=https://web.archive.org/web/20211230170305/https://soldiersystems.net/2018/08/02/first-look-socoms-new-suppressed-upper-receiver-group-from-sig-sauer/ |archive-date=30 December 2021 |date=2 August 2018}}

The SIG MCX family has undergone three generations of modifications.

The SIG MCX is available with a safe/semi-automatic trigger group for the U.S. civilian market, or safe/semi-automatic/fully automatic trigger group for the military and law enforcement agencies.

SIG Sauer offers the MCX 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 short-barreled rifle configuration of the rifle with a 229 mm (9 in) barrel. {{efn|Under U.S. federal law, rifles with barrels shorter than 16 inches are Title II weapons, which are subject to federal restrictions, as well as being regulated by state laws}}
• The SIG MCX Pistol is the pistol 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). {{efn|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}}Federal Gun Control Act 1968 [https://www.law.cornell.edu/uscode/text/18/921 18 U.S. Code § 921 - Definitions], Cornell.edu, "(29) The term “handgun” means— (A) a firearm which has a short stock and is designed to be held and fired by the use of a single hand" though it is really a compact carbine rifle, as it fires an intermediate round. {{efn|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.{{cite web|url=http://www.grandviewoutdoors.com/grand-view-outdoors/the-rise-and-fall-of-the-sb-15-sig-brace/|title=The Rise And Fall Of The SB-15 'Sig Brace'|date=24 March 2015|website=Grand View Outdoors|access-date=2 August 2016|archive-date=25 October 2016|archive-url=https://web.archive.org/web/20161025092346/http://www.grandviewoutdoors.com/grand-view-outdoors/the-rise-and-fall-of-the-sb-15-sig-brace/|url-status=dead}} However, as of April 2017, this is no longer the case'').{{cite web|url=https://www.nraila.org/articles/20170425/brace-yourself-atf-reconsiders-obama-era-policy-on-stabilizing-braces|title=Brace Yourself: ATF Reconsiders Obama-Era Policy on Stabilizing Braces|date=25 April 2017|website=National Rifle Association Institute for Legislative Action}}}}

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".{{cite web|url=http://www.militarytimes.com/story/military/gearscout/2014/04/17/on-the-range-with-sig-sauers-mcx-black-mamba/32150065/|title=On the range with Sig Sauer's MCX 'Black Mamba'|date=17 April 2014|website=Military Times}}{{cite book|url=https://books.google.com/books?id=v1yqCwAAQBAJ&pg=PA142|title=Guns of Special Forces 2001 – 2015|last=Neville|first=Leigh|date=31 March 2016|publisher=Casemate Publishing|isbn=978-1-4738-8102-0|pages=142–143}}

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.{{cite web|url=https://www.gunsamerica.com/digest/ready-mission-sig-sauer-mcx-virtus-full-review/|title=Ready for Any Mission: SIG Sauer MCX Virtus — Full Review|last=Martin|first=Clay|website=gunsamerica.com|date=3 November 2017|language=en|access-date=January 5, 2019}}{{cite web|url=https://www.sigsauer.com/store/sig-mcx-virtus-patrol.html|title=Sig MCX VIRTUS Patrol|website=sigsauer.com|language=en|access-date=January 5, 2019}}
• 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.{{cite web|url=https://www.sigsauer.com/store/sig-mcx-virtus-sbr.html|title=Sig MCX VIRTUS SBR|website=sigsauer.com|language=en|access-date=January 5, 2019}}
• 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.{{cite web|url=https://www.sigsauer.com/store/sig-mcx-virtus-pistol.html|title=Sig MCX VIRTUS Pistol|website=sigsauer.com|language=en|access-date=January 5, 2019}}

The SIG MCX RATTLER is a short-barreled rifle variant chambered in .300 AAC Blackout and 5.56. It is intended to serve as a personal defense weapon, featuring a {{convert|140|mm|in|abbr=on}} barrel, and comes with a Picatinny rail tail interface for attaching either a compact buttstock or a folding PCB (pistol contour brace).{{cite web |title=SIG MCX RATTLER SBR |url=https://www.sigsauer.com/sig-mcx-rattler-sbr.html |website=SIG Sauer |access-date=24 May 2022 |archive-url=https://web.archive.org/web/20220520152804/https://www.sigsauer.com/sig-mcx-rattler-sbr.html |archive-date=20 May 2022}} In February 2018, USSOCOM ordered upper receiver group conversion kits for the MCX Rattler in .300BLK for evaluation.{{cite web |last1=Moss |first1=Matthew |title=SOCOM to Evaluate SIG Sauer's MCX Rattler |url=https://www.thefirearmblog.com/blog/2018/02/09/socom-to-test-sig-sauers-mcx-rattler/ |website=The Firearm Blog |access-date=24 May 2022 |archive-url=https://web.archive.org/web/20210720194613/https://www.thefirearmblog.com/blog/2018/02/09/socom-to-test-sig-sauers-mcx-rattler/ |archive-date=20 July 2021 |date=9 February 2018}}

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.{{cite web |last1=Moss |first1=Matthew |title=SIG Sauer Rattler Wins US SOCOM Personal Defense Weapon Contract |url=https://www.thefirearmblog.com/blog/2022/05/23/sig-sauer-rattler-wins-us-socom-personal-defense-weapon-contract/ |website=The Firearm Blog |access-date=24 May 2022 |archive-url=https://web.archive.org/web/20220524230844/https://www.thefirearmblog.com/blog/2022/05/23/sig-sauer-rattler-wins-us-socom-personal-defense-weapon-contract/ |archive-date=24 May 2022 |date=23 May 2022}}

The SIG MCX-SPEAR LT is the third generation of the SIG MCX, introduced in 2022. With the release of the MCX-SPEAR LT, SIG also designed a new, padded, side-folding stock with an FDE finish option to match the rifles, which civilian versions of the rifle variant are sold with. While the civilian variant is referred to as the "SPEAR LT", referencing the SPEAR from which it derives many of its improvements over the Virtus line, SIG Sauer refers to the military versions as simply the "MCX LT" or "MCX Lightweight".{{cite web |title=Defense Strategies Catalog |url=https://www.sigsauer.com/dsg |website=SIG Sauer |access-date=7 August 2024}}

The defining features of the LT are its new, lightened, handguard and barrel design (borrowed from the SPEAR) ambidextrous bolt catch and release, proprietary SL muzzle device to allow for the use of SIG SAUER's quick detaching SLX and SLH suppressors, and new coyote brown coating (black options are still available for purchase). Intended to serve as a carbine, the civilian model features {{convert|11.5|in|mm|adj=on}} or {{convert|16|in|mm|adj=on}} barrel and a Picatinny rail tail interface for attaching either a buttstock or a pistol brace. The military model features both of these options, with the addition of {{convert|14.5|in|mm|adj=on}} and {{convert|9|in|mm|adj=on}} barrels, as well as a custom two-stage match grade select-fire trigger group. It is available in 5.56 mm NATO, .300 Blackout and a 7.62x39mm version with custom 28 round AR-pattern magazines.{{Cite web | url=https://www.sigsauer.com/mcx-spear-lt.html| title=Sig MCX-SPEAR LT| website=SIG Sauer }}{{Cite web |date=2022-09-18 |title=Introducing the new Sig MCX-SPEAR LT |url=https://www.thefirearmblog.com/blog/2022/09/18/sig-mcx-spear-lt/ |website=The Firearm Blog}}

{{main|SIG MCX-SPEAR}}

{{For|the U.S. Army adopted variant of the MCX SPEAR|XM7 rifle}}

The SIG MCX-SPEAR was developed as SIG Sauer's submission for the United States Army Next Generation Squad Weapon (NGSW) program and is chambered in 6.8×51mm SIG Fury cartridge.{{Cite web|url=https://www.sigsauer.com/dsg|title = U.S. Military and Agency Sales | SIG SAUER}}{{Cite web|url=https://modernfirearms.net/en/assault-rifles/u-s-a-assault-rifles/ngsw-r-sig-mcx-spear-2/|title = SIG Sauer NGSW-R MCX Spear assault rifle (USA)|date = December 2019}}{{Cite web|url=https://www.gunpowdermagazine.com/sig-mcx-spear-the-u-s-armys-next-riflesig-mcx-spear-the-u-s-armys-next-rifle/|title=SIG MCX Spear: The U.S. Army's Next Rifle?|date=23 March 2021|access-date=31 May 2021|archive-date=23 January 2022|archive-url=https://web.archive.org/web/20220123094342/https://www.gunpowdermagazine.com/sig-mcx-spear-the-u-s-armys-next-riflesig-mcx-spear-the-u-s-armys-next-rifle/|url-status=dead}}{{Cite web|url=https://www.thefirearmblog.com/blog/2021/01/15/tfb-gunfest-the-sig-sauer-mcx-spear-ngsw-rifle/|title = [TFB GUNFEST] the SIG Sauer MCX Spear NGSW Rifle -|date = 15 January 2021}} SIG Sauer was chosen as the winner on 19 April 2022, formerly designated as the XM5 then was later changed to the XM7 in U.S. military service.[https://www.armytimes.com/news/your-army/2022/04/19/army-chooses-sig-sauer-to-build-its-next-generation-squad-weapon/ Army chooses Sig Sauer to build its Next Generation Squad Weapon]. Army Times. 19 April 2022.

The SIG MCX-MR (Mid Range) was SIG Sauer's unsuccessful submission for the United States Army's Compact Semi-Automatic Sniper System (CSASS) program.{{cite news|url=http://www.armytimes.com/story/military/2016/04/08/hk-confirms-armys-new-and-improved-sniper-rifle/82788202/|title=H&K confirms: This is the Army's new and improved sniper rifle|last=Jahner|first=Kyle|date=8 April 2016|access-date=9 June 2016|website=Army Times}} It is chambered in 7.62×51mm NATO and has selective fire capabilities. It weighs {{convert|8.9|lb||abbr=on}} and features a 406 mm (16 in) fluted, 416 stainless steel barrel, with a 1:10 inch twist, which is manufactured by Bartlein Barrels. The gas system features suppressed and unsuppressed settings. Unlike the handguard of the MCX, which slides off after pulling the front pivot pin, the MCX-MR requires popping off two screws first. It features both an M16/AR-15 type charging handle and a left side charging handle. It uses a 20-round SR-25 box magazines.{{cite web|url=http://www.recoilweb.com/recoil-exclusive-sig-sauer-csass-the-mcx-mr-65405.html|first=David|last=Merrill|publisher=Recoil|title=RECOIL Exclusive: An Inside Look at Sig Sauer's CSASS – The MCX-MR|date=21 May 2015}}

File:SIG MCX Users.png

• {{AUS}}: MCX Rattler Used by the NSW Police Force Tactical Operations Unit{{cite magazine |last1=André |first1=Dom |title=TOU Australia |magazine=FLASHBANG |issue=12 |url=https://flashbang-magazine.com/ecommerce/index.php/magazine/fall-2019-edition-012.html |access-date=14 March 2023 |publisher=NIMROD|location=France |date=Fall 2019|page=30}} and Victoria Police Special Operations Group in .300BLK.{{cite news|last1=Dowsley|first1=Anthony|title=Victoria Police special operations, critical incident teams get new guns|url=http://www.heraldsun.com.au/news/victoria/victoria-police-special-operations-critical-incident-teams-get-new-guns/news-story/319a3652c4a8bf0cb6ceaa8107f0e351|work=Herald Sun|date=25 March 2017|archive-url=https://archive.today/20171118051536/http://www.heraldsun.com.au/news/victoria/victoria-police-special-operations-critical-incident-teams-get-new-guns/news-story/319a3652c4a8bf0cb6ceaa8107f0e351|archive-date=18 November 2017|url-status=dead|df=dmy-all}}{{cite magazine |last1=André |first1=Dom |title=SOG (Australia) |magazine=FLASHBANG |issue=11 |url=https://flashbang-magazine.com/ecommerce/index.php/magazine/summer-2018-edition-010.html |access-date=14 March 2023 |publisher=NIMROD|location=France |date=Summer 2018|page=60}} SIG MCX in .300BLK is being acquired for Army special forces units from 2024 to replace the H&K MP5.{{cite news |last=Joseph |first=Cpl Jacob |title=Armoury overhauled |url=https://downloads.realviewdigital.com/pdf/army-news/october-13-2022.pdf |work=Army: The Soldiers' Newspaper |edition=1522 |date=13 October 2022 |publisher=Department of Defence |location=Canberra, Australia |issn=0729-5685 |page=8 |access-date=14 March 2023 |archive-date=27 October 2022 |archive-url=https://web.archive.org/web/20221027101648/https://downloads.realviewdigital.com/pdf/army-news/october-13-2022.pdf |url-status=dead }}{{cite press release |title=ADF signs up for next generation of weapons |url=https://www.defence.gov.au/news-events/releases/2022-09-30/adf-signs-next-generation-weapons |website=Department of Defence |access-date=13 March 2023 |date=30 September 2022}}
• {{BEL}}: DSU{{Cite web|url=https://static.standaard.be/Assets/Images_Upload/2021/05/21/504fda0e-b976-11eb-ac44-720add958143.jpg?width=1024&format=jpg|title=DSU Operator using a SIG MCX}} and the special response unit of the Ghent local police (COPS){{Cite web|url=https://ebesluitvorming.gent.be/zittingen/17.0707.9989.9721/agendapunten/17.1106.1269.9602|title=Raadpleegomgeving - Open Data - Agendapunt|website=ebesluitvorming.gent.be}}
• {{CAN}}: Saskatchewan Conservation Officers,{{cite web|title=Sask. seals deals to equip conservation officers with carbines|url=https://www.cbc.ca/news/canada/saskatchewan/sask-conservation-officers-ammunition-carbines-1.4988312|url-status=live|publisher=CBC News|date=23 January 2019|access-date=23 July 2022|archive-url=https://web.archive.org/web/20220520152944/https://www.cbc.ca/news/canada/saskatchewan/sask-conservation-officers-ammunition-carbines-1.4988312|archive-date=20 May 2022}} Canadian Special Operations Forces Command
• {{Flag|Denmark}}: Jægerkorpset,{{Cite web |publisher=Jægerkorpset |date=2023-02-08 |title=Særligt udvalgt, trænet og udrustet - ligesom vores operatører. . |url=https://www.instagram.com/accounts/login/?next=https%3A%2F%2Fwww.instagram.com%2Fp%2FCoZo7j5tdUn%2F |access-date=2023-05-24 |via=www.instagram.com}} Rigspolitiet phasing in until 2027.{{Cite web |publisher=Rigspolitiet|date=2024-06-06 |title=Rigspolitiet har underskrevet kontrakt om indkøb af ny karabin|url=https://politi.dk/rigspolitiet/nyhedsliste/rigspolitiet-har-underskrevet-kontrakt-om-indkoeb-af-ny-karabin/2024/06/06 |access-date=2024-06-06 }}
• {{EST}}: Used by the K-Commando{{Cite web|url=https://xn--snumid-pxa.ee/2018/06/suure-politseioppuse-kaigus-harjutati-ohtlike-kurjategijate-tabamist/|title=FOTOD: Suure politseiõppuse käigus harjutati ohtlike kurjategijate tabamist|date=June 20, 2018|access-date=April 28, 2020|archive-date=June 11, 2020|archive-url=https://web.archive.org/web/20200611005301/https://xn--snumid-pxa.ee/2018/06/suure-politseioppuse-kaigus-harjutati-ohtlike-kurjategijate-tabamist/|url-status=dead}}
• {{FRA}} : Groupement de commandos de montagne, 27th Mountain Infantry Brigade, 5 in 2021.{{cite web|url=https://www.facebook.com/421384361224512/posts/4868222473207323/|title=7e Bataillon de Chasseurs Alpins Facebook page|work=Facebook|date=22 September 2021}}
• {{GER}}: Berlin Police, 300 modified MCXs to meet the police's requirements were ordered in October 2017,{{Cite web|url=https://www.bild.de/regional/berlin/isis-terroristen/das-neue-anti-terror-gewehr-53509630.bild.html|title=Sturmgewehr soll Terroristen abschrecken - Neue Super-Waffe für Berliner Polizisten|website=bild.de|date=12 October 2017 }} plus an additional 160 units for the SEK of Berlin,{{Cite web|url=https://strategie-technik.blogspot.com/2017/11/streifenbuchse-in-schleswig-holstein.html|title=STRATEGIE & TECHNIK: Streifengewehr in Schleswig-Holstein: 522 SIG MCX für die Landespolizei|date=November 25, 2017}} Landespolizei of Schleswig Holstein, 531 units delivered, but being replaced with HK 437 because the rifles had shortcomings{{cite web | url=https://www.ndr.de/nachrichten/schleswig-holstein/Landespolizei-Schleswig-Holstein-erhaelt-neue-Waffen,polizei6964.html | title=Polizei in Schleswig-Holstein erhält neue Waffen }} Rhineland-Palatinate Police: more than 100 rifles ordered in late 2019.{{Cite web|url=https://www.sueddeutsche.de/panorama/terrorismus-mainz-rheinland-pfalz-stattet-einheit-mit-mitteldistanzwaffen-aus-dpa.urn-newsml-dpa-com-20090101-191214-99-139065!amp|title=Rheinland-Pfalz stattet Einheit mit Mitteldistanzwaffen aus|website=www.sueddeutsche.de|access-date=2020-02-02|archive-date=2021-06-30|archive-url=https://web.archive.org/web/20210630200014/https://www.sueddeutsche.de/panorama/terrorismus-mainz-rheinland-pfalz-stattet-einheit-mit-mitteldistanzwaffen-aus-dpa.urn-newsml-dpa-com-20090101-191214-99-139065!amp|url-status=dead}}
• {{ISR}}: Used by Shayetet 13, the Israel Defense Forces Naval Commando unit.http://www.ynet.co.il/articles/0,7340,L-5043218,00.html (Hebrew)
• {{Flag|Italy}}: Used by Comando Raggruppamento Subacquei e Incursori Teseo Tesei (Frogmen) of the Italian Navy.{{Cite web |date=2019-05-22 |title=La situazione delle forze armate italiane: l'armamento degli incursori di Marina |url=https://www.difesaonline.it/mondo-militare/la-situazione-delle-forze-armate-italiane-larmamento-degli-incursori-di-marina-0 |access-date=2024-08-19 |website=Difesa Online |language=it}}
• {{IDN}}: Used by Kopassus (Special Forces Command) of the Indonesian Army in limited service; Detachment 88 and Mobile Brigade Corps of the Indonesian National Police;{{Cite web |last=Law-justice.co |date=2018-12-12 |title=Tim Densus 88 Tangkap 1 Orang Terkait Terorisme di Sleman |url=https://www.law-justice.co/artikel/56920/tim-densus-88-tangkap-1-orang-terkait-terorisme-di-sleman/ |access-date=2025-05-31 |website=www.law-justice.co |language=id}}{{Cite web |last=Polsek.Cilandak |first= |date=2020-12-17 |title=Calling all Indonesian police to answer Tom Delonge’s statement about this! |url=https://www.instagram.com/p/CI53BDpnXkd/?utm_source=ig_embed&utm_campaign=loading&img_index=3 |access-date=2025-05-31 |website=www.instagram.com}}{{Cite web |date=2022-03-04 |title=Akun Resmi Polsek Cilandak (@polsek.cilandak) on Instagram {{!}} Ghostarchive |url=https://ghostarchive.org/iarchive/instagram/polsek.cilandak/2462645403746386523_2462645401221416195 |access-date=2025-05-31 |website=ghostarchive.org}}{{Cite web |last=admin |date=2021-02-07 |title=Pengenalan Senjata Sig Sauer Personel Yon D Resimen 1 Paspelopor |url=https://investigasibhayangkara.com/pengenalan-senjata-sig-sauer-personel-yon-d-resimen-1-paspelopor/ |access-date=2023-01-13 |website=INVESTIGASI BHAYANGKARA |language=id}} Also used by Kopasgat (Quick Reaction Forces Command) of the Indonesian Air Force;{{Cite web |last=Kurniawan |first=Sigit |date=2022-12-16 |title=Saat pasukan elite TNI AU latih jurnalis meliput medan perang |url=https://elshinta.com/news/287841/2022/12/16/saat-pasukan-elite-tni-au-latih-jurnalis-meliput-medan-perang |access-date= |website=elshinta.com |language=id-ID}}{{Cite web |last=Kopasgat |date=2024-03-20 |title=Detasemen Matra 1 Kopasgat Menerima OJT (On The Job Training) Taruna Tingkat IV Kecabangan Pasukan |url=https://tni-au.mil.id/berita/detail/detasemen-matra-1-kopasgat-menerima-ojt-on-the-job-training-taruna-tingkat-iv-kecabangan-pasukan |access-date= |website=tni-au.mil.id |language=Indonesian}} and Koopssus (Special Operations Command) of the Indonesian National Armed Forces.{{Cite web |last=law-justice.co |date=2019-08-03 |title=Apa Saja Senjata Canggih yang Bakal Digunakan Koopssus TNI? |url=https://www.law-justice.co/artikel/69731/apa-saja-senjata-canggih-yang-bakal-digunakan-koopssus-tni/ |access-date= |website=www.law-justice.co |language=id}}{{Cite web |last=Puspen TNI |date=2024-08-30 |title=Koopssus TNI Laksanakan Persiapan Dalam Rangka HLF MSP dan IAF di Bali |url=https://x.com/Puspen_TNI/status/1829445148251750504 |website=x.com/Puspen_TNI}}
• {{NLD}}: Used by the Netherlands Maritime Special Operations Forces and the Dienst Speciale Interventies. All rifles acquired in .300 AAC Blackout and fitted with the SIG Suppressed Upper Receiver.{{cite web|url=http://www.janes.com/article/65747/sig-mcx-rifles-delivered-to-dutch-special-forces|title=SIG MCX rifles delivered to Dutch special forces|date=24 November 2016|first=Remigiusz|last=Wilk|website=IHS Jane's 360|publisher=IHS Jane's Defence Weekly}}{{cite news |title=Dutch MARSOF officially purchase .300 BLK SIG MCX Rifles |url=https://www.thefirearmblog.com/blog/2016/12/09/dutch-marsof-officially-purchase-300-blk-sig-mcx-rifles/ |work=The Firearm Blog |date=2016-12-09}}
• {{POL}}: Jednostka Wojskowa Grom and JW Formoza acquired the SIG MCX VIRTUS and MCX RATTLER in .300 AAC Blackout with conversion kits to 5.56×45mm NATO and 7.62×39mm ammunition.{{Cite web|last=Pacholski|first=Łukasz|date=2021-05-28|title=Operatorzy Formozy otrzymają nowe karabinki automatyczne|url=https://radar.rp.pl/modernizacja-sil-zbrojnych/23187-operatorzy-formozy-otrzymaja-nowe-karabinki-automatyczne|access-date=2021-06-12|website=Radar|language=pl-PL}} Also used by Internal Security Agency{{cite news |title=ABW celuje w nową amunicję i granaty hukowe |url=https://infosecurity24.pl/sluzby-specjalne/agencja-bezpieczenstwa-wewnetrznego/abw-celuje-w-nowa-amunicje-i-granaty-hukowe |work=InfoSecurity24 |date=2020-12-11 |language= pl}} and State Protection Service{{cite news |title=SOP na broni nie oszczędza |url=https://infosecurity24.pl/sluzby-mundurowe/sluzba-ochrony-panstwa/sop-na-broni-nie-oszczedza |work=InfoSecurity24 |date=2023-06-07 |language= pl}}
• {{PRT}}: Polícia de Segurança Pública acquired SIG MCX in 5.56×45mm NATO. Used by Special Operations Group (Portugal).{{Cite web|url=https://www.psp.pt/Pages/apsp/unidadesPolicia.aspx?menu=1&submenu=2|title=Policia de Segurança Publica :: A PSP :: Quem Somos :: Unidades de Policia|website=www.psp.pt|access-date=2020-02-13|archive-date=2019-01-23|archive-url=https://web.archive.org/web/20190123121305/http://www.psp.pt/Pages/apsp/unidadesPolicia.aspx?menu=1&submenu=2|url-status=dead}}
• {{flag|Switzerland}}: Used by the Geneva Police.{{cite web|url=https://www.ghi.ch/le-journal/la-une/nouveau-matos-de-la-police-cest-du-lourd|title=Nouveau matos de la police: c'est du lourd!|date=2 April 2019|access-date=12 June 2023}}
• {{flag|Spain}}: Used by Spanish Navy{{Cite web |last=Saballa |first=Joe |date=2023-11-06 |title=Spanish Navy Buys Sig Sauer MCX Submachine Guns |url=https://www.thedefensepost.com/2023/11/06/spanish-navy-submachine-guns/ |access-date=2024-01-12 |website=The Defense Post |language=en-us}} and Civil Guard{{Cite web |date=2023-01-11 |title=Spain get MCX Rattler similar to AR-15/M4 firing the .300BLK |url=https://bulgarianmilitary.com/2023/01/11/spain-get-mcx-rattler-similar-to-the-ar-15-m4-firing-the-300-blk/ |access-date=2024-01-12 |language=en-US}}
• {{UKR}}: Used by the SBU Alpha Group.{{cite web|url=https://24tv.ua/specpodrazdelenie_alfa_i_boevye_mashiny_sbu_budet_rabotat_v_den_vyborov_2019__foto_i_video_n1134474?lang=ru|title=Спецподразделение "Альфа" и боевые машины: СБУ будет работать в день выборов 2019 – фото и видео|date=30 March 2019|access-date=28 April 2020}}
• {{flag|Sweden}}: Used by Swedish Military Intelligence and Security Service National Intelligence Unit.{{Cite web|url=https://officerstidningen.se/tilltrade-till-musts-krigsforband/ |website=www.officertidninge.se|access-date=2024-08-05 |title=Tillträde till Musts krigsförband |date=2 November 2023 }}
• {{UK}}: Used by the Police Counter Terrorist Specialist Firearms Officers including the Metropolitan Police Service{{cite web|url=https://www.eliteukforces.info/uk-military-news/17112015-SCO19-mcx.php|title=SCO19 Spotted With MCX Carbine|work=Elite UK Forces|date=17 November 2015|access-date=16 March 2020}} and United Kingdom Special Forces to replace the HK MP5SD3s.{{cite book |last1=Neville |first1= Leigh|title=The Elite: The A-Z of Modern Special Operations Forces|publisher= Osprey Publishing|year=2019 |isbn=978-1472824295}}p.43 Used by 42 Commando Royal Marines to replace their L119 carbines.{{cite web|url=https://www.forcesnews.com/services/royal-marines/royal-marines-show-amphibious-force-new-youtube-film|title=Royal Marines showcase their amphibious force in newly released YouTube film|work=Forces News|date=12 February 2025|access-date=12 February 2025}} In March 2025, 1,500 rifles were ordered for the Royal Marines.{{cite web|url=https://www.forcesnews.com/services/royal-marines/mcx-joins-ks-1-commando-force-upgrades-its-armoury-new-rifle|title=MCX joins KS-1 as Commando Force upgrades its armoury with new rifle|work=Forces News|date=9 March 2025|access-date=9 March 2025}}{{cite web|url=https://thedefensepost.com/2025/03/11/royal-marines-sig-sauer-rifles/|title=Royal Marines From UK Commando Force Adopt Sig Sauer Rifles|work=The Defense Post|date=11 March 2025|access-date=11 March 2025}}
• {{USA}}: various models including the RSAR (Reduced Signature Assault Rifle), LVAW (Low Visibility Assault Weapon) and the CSAW (Close Support Assault Weapon) are used by Joint Special Operations Command{{Cite web|date=2021-08-09|title=This LVAW is SOCOM's overpowered answer to the SMG|url=https://www.sandboxx.us/blog/this-lvaw-is-socoms-overpowered-answer-to-the-smg/|access-date=2021-12-23|website=Sandboxx|language=en-US}}

• AR-15 style rifle
• LR-300, another folding stock AR-15 style rifle
• AR-18, another folding stock assault rifle which its operating mechanism being used on the MCX

{{notelist}}

{{Reflist}}

• {{commons category-inline}}
• {{Wikiquote-inline}}
• [https://www.sigsauer.com/firearms/rifles-pistols/sig-mcx.html SIG MCX] on SIG Sauer's official website
• [https://www.sigsauer.com/wp-content/uploads/2016/07/MCX.pdf sigsauer.com] {{Webarchive|url=https://web.archive.org/web/20200825160824/https://www.sigsauer.com/wp-content/uploads/2016/07/MCX.pdf |date=2020-08-25 }}
• [https://www.thefirearmblog.com/blog/2019/11/26/sig-sauer-mcx-rifle/ Guide To The SIG Sauer MCX - The Firearm Blog]

{{ArmaLite AR-10 derivatives}}

{{SIG Sauer Rifles}}

{{Personal defense weapons}}

Category:.300 BLK firearms

Category:5.56×45mm NATO assault rifles

Category:5.56×45mm NATO semi-automatic rifles

Category:7.62×39mm assault rifles

Category:Assault rifles of the United States

Category:Semi-automatic rifles of the United States

Category:Short stroke piston firearms

Category:Weapons and ammunition introduced in 2015

Category:ArmaLite AR-10 derivatives

Category:AR-15 style rifles

Category:Designated marksman rifles

Category:Carbines

Category:Personal defense weapons

Category:SIG Sauer rifles