SIG MCX explained

SIG MCX
Origin:	United States^[1]
Type:	Assault rifle Carbine Semi-automatic rifle
Is Ranged:	Yes
Service:	2015–present
Manufacturer:	SIG Sauer
Unit Cost:	MCX VIRTUS Patrol: MSRP US$2,233 MCX VIRTUS SBR: MSRP US$2,233 MCX VIRTUS Pistol: MSRP US$2,235^[2]
Production Date:	2015–present
Variants:	See Variants
Weight:	2.61kg (05.75lb) (229 mm barrel) 2.72kg (06lb) (292 mm barrel) 3.6kg (07.9lb) (406 mm barrel)
Length:	730mm stock unfolded (229 mm barrel) 908mm stock unfolded (406 mm barrel)
Part Length:	229mm 292mm 406mm
Cartridge:	5.56×45mm NATO .300 AAC Blackout 7.62×39mm
Action:	Short-stroke gas-operated piston, rotating bolt
Velocity:	MCX Carbine 5.56×45mm NATO: 3,000 ft/s (914 m/s)^[3]
Range:	MCX Carbine 5.56×45mm NATO: 1,650 ft (503 m)
Feed:	30-round detachable STANAG box magazine
Sights:	Picatinny rail for mounting iron or optical sights
Rate:	800–900 rounds/min

The SIG MCX is a family of firearms designed and manufactured by SIG Sauer, produced in both selective fire and semi-automatic only models, and features a short-stroke gas piston system, which is inherited from the earlier SIG MPX submachine gun. The MCX is available in rifle, carbine, short-barreled rifle, and pistol configurations (the latter configuration generally conforming to the definition of a compact carbine but for taking a pistol brace rather than a buttstock).^[4]

The MCX was further developed into the SIG MCX Spear, which was adopted in its .277 Fury chambering as the XM7 by the U.S. Army in 2022.

History

The SIG MCX was first introduced at SHOT Show 2015. The rifle was originally designed by SIG USA, the subsidiary of SIG Sauer based in New Hampshire.^[1] In 2016, SIG recalled some of the rifles that had the first-generation bolt carrier group.^[5] 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 at the time was the deadliest mass shooting in U.S. history, now second to the 2017 Las Vegas shooting.^[6]

Design

The SIG MCX series features a short-stroke gas piston^[7] system to reduce recoil and improve the reliability of the weapon;^[8] this was based on the design of the earlier SIG MPX.^[9] The MCX features a system that allows for 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.^[9] The MCX is designed to deliver optimal performance with .300 AAC Blackout and an optional suppressor.^[10]

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.^{[11] [12]} It features hardened steel wear points.^{[9] [11]}

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.^{[9] [12]} The overall layout of the two rifles is similar.^[13] SIG designed the upper receiver to be compatible with standard AR-15 and M16 lower receivers^{[9] [11]} with the help of an adapter.^[14]

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.^{[15] [16]}

Variants

SIG MCX

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 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 short-barreled rifle 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, 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). (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,^[17] 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.^[18] However, as of April 2017, this is no longer the case).^[19]
• 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".^{[20] [21]}

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.^{[22] [23]}
• 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.^[24]
• 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.^[25]

SIG MCX RATTLER

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 140mm barrel, and comes with a Picatinny rail tail interface for attaching either a compact buttstock or a folding PCB (pistol contour brace).^[26] In February 2018, USSOCOM ordered upper receiver group conversion kits for the MCX Rattler in .300BLK for evaluation.^[27] 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.^[28]

SIG MCX-SPEAR LT

The SIG MCX-SPEAR LT is the third generation of the SIG MCX, introduced in 2022. With the release of the MCX 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".^[29]

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 11.5inches or 16inches 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 14.5inches and 9inches 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.^{[30] [31]}

Derivatives

SIG MCX-SPEAR

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.^{[32] [33] [34] [35]} 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.^[36]

Users

• : MCX Rattler Used by the NSW Police Force Tactical Operations Unit^[37] and Victoria Police Special Operations Group in .300BLK.^{[38] [39]} SIG MCX in .300BLK is being acquired for Army special forces units from 2024 to replace the H&K MP5.^{[40] [41]}
• : DSU^[42] and the special response unit of the Ghent local police (COPS)^[43]

Saskatchewan Conservation Officers,^[44] Canadian Special Operations Forces Command

Jægerkorpset,^[45] Rigspolitiet phasing in until 2027.^[46]

• : Used by the K-Commando^[47]
• : Groupement de commandos de montagne, 27th Mountain Infantry Brigade, 5 in 2021.^[48]
• : Berlin Police, 300 modified MCXs to meet the police's requirements were ordered in October 2017,^[49] plus an additional 160 units for the SEK of Berlin,^[50] Landespolizei of Schleswig Holstein, 531 units delivered, but being replaced with HK 437 because the rifles had shortcomings^[51] Rhineland-Palatinate Police: more than 100 rifles ordered in late 2019.^[52]
• : Used by Shayetet 13, the Israel Defense Forces Naval Commando unit.^[53]
• : Used by Comando Raggruppamento Subacquei e Incursori Teseo Tesei (Frogmen) of the Italian Navy.^[54]
• : Used by Kopassus, Indonesian Special forces commando in limited service and so does Mobile Brigade Corps^[55]
• : 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.^{[56] [57]}
• : 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.^[58] Also used by Internal Security Agency^[59] and State Protection Service^[60]
• : Polícia de Segurança Pública acquired SIG MCX in 5.56×45mm NATO. Used by Special Operations Group (Portugal).^[61]
• Switzerland: Used by the Geneva Police.^[62]
• Spain: Used by Spanish Navy^[63] and Civil Guard^[64]
• : Used by the SBU Alpha Group.^[65]
• Sweden: Used by Swedish Military Intelligence and Security Service National Intelligence Unit.^[66]
• : Used by the Police Counter Terrorist Specialist Firearms Officers including the Metropolitan Police Service^[67] and United Kingdom Special Forces to replace the HK MP5SD3s.^[68]
• : XM7 being acquired for all DoD branches. SIG MCX Rattler and RSAR (Reduced Signature Assault Rifle) in .300BLK are being acquired for USSOCOM forces. The LVAW (Low Visibility Assault Weapon) and the CSAW (Close Support Assault Weapon) variants are used by Joint Special Operations Command, notably Delta Force.^[69]

See also

• 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

External links

• • • SIG MCX on SIG Sauer's official website
• sigsauer.com
• Guide To The SIG Sauer MCX - The Firearm Blog

Notes and References

1. Web site: The Introduction of the MCX Assault Rifle. Violence Policy Center. June 2016. Understanding the Sig Sauer MCX Assault Rifle Used in the Orlando Mass Shooting. 7 February 2021.
2. Web site: MCX VIRTUS. sigsauer.com. en. January 5, 2019.
3. Web site: SIG MCX . Military Factory . en. January 5, 2019.
4. Web site: 2017 SIG SAUER Catalog. dcatalog.com. SIG Sauer. 26 February 2017.
5. Web site: Sig Sauer MCX Mandatory Recall. 24 December 2014. SOFREP News.
6. News: The gun the Orlando shooter used was a Sig Sauer MCX, not an AR-15. That doesn't change much.. Gibbons-Neff. Thomas. The Washington Post. Washington, D.C.. 2017-07-23.
7. Web site: SILENCER SATURDAY #226: The MCX Virtus Piston System. The Firearm Blog. April 30, 2022. April 30, 2022.
8. Web site: Is the Sig Sauer MCX Virtus Patrol Better Than an AR-15?. The National Interest. December 21, 2021. December 21, 2021.
9. Web site: First Look: SIG Sauer MCX . Guns & Ammo . https://web.archive.org/web/20190224001742/http://www.gunsandammo.com/editorial/sig-sauer-mcx/249535 . 24 February 2019 . January 13, 2015.
10. News: SIG Sauer MCX Carbine. American Rifleman.
11. Web site: RECOIL Exclusive: Breakdown of the Sig MCX. David. Merrill. Recoil. 16 January 2015.
12. Web site: Full Review: SIG Sauer MCX. Drew. Warden. October 7, 2015. Gun Digest.
13. Web site: Sig Sauer's MCX Rifle: An Elite Modular Weapons System. 30 June 2015. Sean. Utley. Tactical Life.
14. Web site: AR Lower Receiver Extension Adapter for SIG MCX Upper - Soldier Systems Daily. 9 February 2015 . 2017-06-10.
15. Web site: USSOCOM Awards SIG SAUER $48 Mil for Suppressed Upper Receiver Group . Soldier Systems Daily . 24 May 2022 . https://web.archive.org/web/20210419063506/https://soldiersystems.net/2018/07/29/ussocom-awards-sig-sauer-48-mil-for-suppressed-upper-receiver-group/ . 19 April 2021 . 29 July 2018.
16. Web site: First Look – USSOCOM's New Suppressed Upper Receiver Group (SURG) from SIG SAUER . Soldier System Daily . 24 May 2022 . https://web.archive.org/web/20211230170305/https://soldiersystems.net/2018/08/02/first-look-socoms-new-suppressed-upper-receiver-group-from-sig-sauer/ . 30 December 2021 . 2 August 2018.
17. Federal Gun Control Act 1968 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"
18. Web site: The Rise And Fall Of The SB-15 'Sig Brace'. 24 March 2015. Grand View Outdoors. 2 August 2016. 25 October 2016. https://web.archive.org/web/20161025092346/http://www.grandviewoutdoors.com/grand-view-outdoors/the-rise-and-fall-of-the-sb-15-sig-brace/. dead.
19. Web site: Brace Yourself: ATF Reconsiders Obama-Era Policy on Stabilizing Braces. 25 April 2017. National Rifle Association Institute for Legislative Action.
20. Web site: On the range with Sig Sauer's MCX 'Black Mamba'. 17 April 2014. Military Times.
21. Book: Neville, Leigh. Guns of Special Forces 2001 – 2015. 31 March 2016. Casemate Publishing. 978-1-4738-8102-0. 142–143.
22. Web site: Ready for Any Mission: SIG Sauer MCX Virtus — Full Review. Martin. Clay. gunsamerica.com. 3 November 2017. en. January 5, 2019.
23. Web site: Sig MCX VIRTUS Patrol. sigsauer.com. en. January 5, 2019.
24. Web site: Sig MCX VIRTUS SBR. sigsauer.com. en. January 5, 2019.
25. Web site: Sig MCX VIRTUS Pistol. sigsauer.com. en. January 5, 2019.
26. Web site: SIG MCX RATTLER SBR . SIG Sauer . 24 May 2022 . https://web.archive.org/web/20220520152804/https://www.sigsauer.com/sig-mcx-rattler-sbr.html . 20 May 2022.
27. Web site: Moss . Matthew . SOCOM to Evaluate SIG Sauer's MCX Rattler . The Firearm Blog . 24 May 2022 . https://web.archive.org/web/20210720194613/https://www.thefirearmblog.com/blog/2018/02/09/socom-to-test-sig-sauers-mcx-rattler/ . 20 July 2021 . 9 February 2018.
28. Web site: Moss . Matthew . SIG Sauer Rattler Wins US SOCOM Personal Defense Weapon Contract . The Firearm Blog . 24 May 2022 . https://web.archive.org/web/20220524230844/https://www.thefirearmblog.com/blog/2022/05/23/sig-sauer-rattler-wins-us-socom-personal-defense-weapon-contract/ . 24 May 2022 . 23 May 2022.
29. Web site: Defense Strategies Catalog . SIG Sauer . 7 August 2024.
30. Web site: Sig MCX-SPEAR LT. .
31. Web site: 2022-09-18 . Introducing the new Sig MCX-SPEAR LT . The Firearm Blog.
32. Web site: U.S. Military and Agency Sales | SIG SAUER.
33. Web site: SIG Sauer NGSW-R MCX Spear assault rifle (USA). December 2019.
34. Web site: SIG MCX Spear: The U.S. Army's Next Rifle?. 23 March 2021.
35. Web site: [TFB GUNFEST] the SIG Sauer MCX Spear NGSW Rifle -. 15 January 2021.
36. 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
37. André . Dom . TOU Australia . FLASHBANG . 12 . 14 March 2023 . NIMROD. France . Fall 2019. 30.
38. News: Dowsley. Anthony. Victoria Police special operations, critical incident teams get new guns. Herald Sun. 25 March 2017. https://archive.today/20171118051536/http://www.heraldsun.com.au/news/victoria/victoria-police-special-operations-critical-incident-teams-get-new-guns/news-story/319a3652c4a8bf0cb6ceaa8107f0e351. 18 November 2017. dead. dmy-all.
39. André . Dom . SOG (Australia) . FLASHBANG . 11 . 14 March 2023 . NIMROD. France . Summer 2018. 60.
40. News: Joseph . Cpl Jacob . Armoury overhauled . Army: The Soldiers' Newspaper . 1522 . 13 October 2022. Department of Defence . Canberra, Australia . 0729-5685. 8 . 14 March 2023.
41. ADF signs up for next generation of weapons . Department of Defence . 13 March 2023 . 30 September 2022.
42. Web site: DSU Operator using a SIG MCX.
43. Web site: Raadpleegomgeving - Open Data - Agendapunt. ebesluitvorming.gent.be.
44. Web site: Sask. seals deals to equip conservation officers with carbines. live. CBC News. 23 January 2019. 23 July 2022. https://web.archive.org/web/20220520152944/https://www.cbc.ca/news/canada/saskatchewan/sask-conservation-officers-ammunition-carbines-1.4988312. 20 May 2022.
45. Web site: Jægerkorpset . 2023-02-08 . Særligt udvalgt, trænet og udrustet - ligesom vores operatører. . . 2023-05-24 . www.instagram.com.
46. Web site: Rigspolitiet. 2024-06-06 . Rigspolitiet har underskrevet kontrakt om indkøb af ny karabin. 2024-06-06 . https://politi.dk.
47. Web site: FOTOD: Suure politseiõppuse käigus harjutati ohtlike kurjategijate tabamist. June 20, 2018.
48. Web site: 7e Bataillon de Chasseurs Alpins Facebook page. Facebook. 22 September 2021.
49. Web site: Sturmgewehr soll Terroristen abschrecken - Neue Super-Waffe für Berliner Polizisten. bild.de. 12 October 2017 .
50. Web site: STRATEGIE & TECHNIK: Streifengewehr in Schleswig-Holstein: 522 SIG MCX für die Landespolizei. November 25, 2017.
51. Web site: Polizei in Schleswig-Holstein erhält neue Waffen .
52. Web site: Rheinland-Pfalz stattet Einheit mit Mitteldistanzwaffen aus. www.sueddeutsche.de. 2020-02-02. 2021-06-30. 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. dead.
53. http://www.ynet.co.il/articles/0,7340,L-5043218,00.html (Hebrew)
54. Web site: 2019-05-22 . La situazione delle forze armate italiane: l'armamento degli incursori di Marina . 2024-08-19 . Difesa Online . it.
55. Web site: admin . 2021-02-07 . Pengenalan Senjata Sig Sauer Personel Yon D Resimen 1 Paspelopor . 2023-01-13 . INVESTIGASI BHAYANGKARA . id.
56. Web site: SIG MCX rifles delivered to Dutch special forces. 24 November 2016. Remigiusz. Wilk. IHS Jane's 360. IHS Jane's Defence Weekly.
57. News: Dutch MARSOF officially purchase .300 BLK SIG MCX Rifles . The Firearm Blog . 2016-12-09.
58. Web site: Pacholski. Łukasz. 2021-05-28. Operatorzy Formozy otrzymają nowe karabinki automatyczne. 2021-06-12. Radar. pl-PL.
59. News: ABW celuje w nową amunicję i granaty hukowe . InfoSecurity24 . 2020-12-11 . pl.
60. News: SOP na broni nie oszczędza . InfoSecurity24 . 2023-06-07 . pl.
61. Web site: Policia de Segurança Publica :: A PSP :: Quem Somos :: Unidades de Policia. www.psp.pt. 2020-02-13. 2019-01-23. https://web.archive.org/web/20190123121305/http://www.psp.pt/Pages/apsp/unidadesPolicia.aspx?menu=1&submenu=2. dead.
62. Web site: Nouveau matos de la police: c'est du lourd!. 2 April 2019. 12 June 2023.
63. Web site: Saballa . Joe . 2023-11-06 . Spanish Navy Buys Sig Sauer MCX Submachine Guns . 2024-01-12 . The Defense Post . en-us.
64. Web site: 2023-01-11 . Spain get MCX Rattler similar to AR-15/M4 firing the .300BLK . 2024-01-12 . en-US.
65. Web site: Спецподразделение "Альфа" и боевые машины: СБУ будет работать в день выборов 2019 – фото и видео. 30 March 2019. 28 April 2020.
66. Web site:

    Officerstidningen :: Officerstidningen :: Officerstidningen

    . www.officertidninge.se. 2024-08-05.
67. Web site: SCO19 Spotted With MCX Carbine. Elite UK Forces. 17 November 2015. 16 March 2020.
68. Book: Neville . Leigh. The Elite: The A-Z of Modern Special Operations Forces. Osprey Publishing. 2019 . 978-1472824295. p.43
69. Web site: 2021-08-09. This LVAW is SOCOM's overpowered answer to the SMG. 2021-12-23. Sandboxx. en-US.