Small Arms Review
  • Home
  • Articles
    • Guns & Parts
    • Suppressors
    • Optics & Thermals
    • Ammunition
    • Gear
    • News & Opinion
    • Columns
    • Museums & Factory Tours
    • ID Guides
    • Interviews
    • Event Coverage
    • Articles by Issue
      • Volume 1
        • V1N1 (Oct 1997)
        • V1N2 (Nov 1997)
        • V1N3 (Dec 1997)
        • V1N4 (Jan 1998)
        • V1N5 (Feb 1998)
        • V1N6 (Mar 1998)
        • V1N7 (Apr 1998)
        • V1N8 (May 1998)
        • V1N9 (Jun 1998)
        • V1N10 (Jul 1998)
        • V1N11 (Aug 1998)
        • V1N12 (Sep 1998)
      • Volume 2
        • V2N1 (Oct 1998)
        • V2N2 (Nov 1998)
        • V2N3 (Dec 1998)
        • V2N4 (Jan 1999)
        • V2N5 (Feb 1999)
        • V2N6 (Mar 1999)
        • V2N7 (Apr 1999)
        • V2N8 (May 1999)
        • V2N9 (Jun 1999)
        • V2N10 (Jul 1999)
        • V2N11 (Aug 1999)
        • V2N12 (Sep 1999)
      • Volume 3
        • V3N1 (Oct 1999)
        • V3N2 (Nov 1999)
        • V3N3 (Dec 1999)
        • V3N4 (Jan 2000)
        • V3N5 (Feb 2000)
        • V3N6 (Mar 2000)
        • V3N7 (Apr 2000)
        • V3N8 (May 2000)
        • V3N9 (Jun 2000)
        • V3N10 (Jul 2000)
        • V3N11 (Aug 2000)
        • V3N12 (Sep 2000)
      • Volume 4
        • V4N1 (Oct 2000)
        • V4N2 (Nov 2000)
        • V4N3 (Dec 2000)
        • V4N4 (Jan 2001)
        • V4N5 (Feb 2001)
        • V4N6 (Mar 2001)
        • V4N7 (Apr 2001)
        • V4N8 (May 2001)
        • V4N9 (Jun 2001)
        • V4N10 (Jul 2001)
        • V4N11 (Aug 2001)
        • V4N12 (Sep 2001)
      • Volume 5
        • V5N1 (Oct 2001)
        • V5N2 (Nov 2001)
        • V5N3 (Dec 2001)
        • V5N4 (Jan 2002)
        • V5N5 (Feb 2002)
        • V5N6 (Mar 2002)
        • V5N7 (Apr 2002)
        • V5N8 (May 2002)
        • V5N9 (Jun 2002)
        • V5N10 (Jul 2002)
        • V5N11 (Aug 2002)
        • V5N12 (Sep 2002)
      • Volume 6
        • V6N1 (Oct 2002)
        • V6N2 (Nov 2002)
        • V6N3 (Dec 2002)
        • V6N4 (Jan 2003)
        • V6N5 (Feb 2003)
        • V6N6 (Mar 2003)
        • V6N7 (Apr 2003)
        • V6N8 (May 2003)
        • V6N9 (Jun 2003)
        • V6N10 (Jul 2003)
        • V6N11 (Aug 2003)
        • V6N12 (Sep 2003)
      • Volume 7
        • V7N1 (Oct 2003)
        • V7N2 (Nov 2003)
        • V7N3 (Dec 2003)
        • V7N4 (Jan 2004)
        • V7N5 (Feb 2004)
        • V7N6 (Mar 2004)
        • V7N7 (Apr 2004)
        • V7N8 (May 2004)
        • V7N9 (Jun 2004)
        • V7N10 (Jul 2004)
        • V7N11 (Aug 2004)
        • V7N12 (Sep 2004)
      • Volume 8
        • V8N1 (Oct 2004)
        • V8N2 (Nov 2004)
        • V8N3 (Dec 2004)
        • V8N4 (Jan 2005)
        • V8N5 (Feb 2005)
        • V8N6 (Mar 2005)
        • V8N7 (Apr 2005)
        • V8N8 (May 2005)
        • V8N9 (Jun 2005)
        • V8N10 (Jul 2005)
        • V8N11 (Aug 2005)
        • V8N12 (Sep 2005)
      • Volume 9
        • V9N1 (Oct 2005)
        • V9N2 (Nov 2005)
        • V9N3 (Dec 2005)
        • V9N4 (Jan 2006)
        • V9N5 (Feb 2006)
        • V9N6 (Mar 2006)
        • V9N7 (Apr 2006)
        • V9N8 (May 2006)
        • V9N9 (Jun 2006)
        • V9N10 (Jul 2006)
        • V9N11 (Aug 2006)
        • V9N12 (Sep 2006)
      • Volume 10
        • V10N1 (Oct 2006)
        • V10N2 (Nov 2006)
        • V10N3 (Dec 2006)
        • V10N4 (Jan 2007)
        • V10N5 (Feb 2007)
        • V10N6 (Mar 2007)
        • V10N7 (Apr 2007)
        • V10N8 (May 2007)
        • V10N9 (Jun 2007)
        • V10N10 (Jul 2007)
        • V10N11 (Aug 2007)
        • V10N12 (Sep 2007)
      • Volume 11
        • V11N1 (Oct 2007)
        • V11N2 (Nov 2007)
        • V11N3 (Dec 2007)
        • V11N4 (Jan 2008)
        • V11N5 (Feb 2008)
        • V11N6 (Mar 2008)
        • V11N7 (Apr 2008)
        • V11N8 (May 2008)
        • V11N9 (Jun 2008)
        • V11N10 (Jul 2008)
        • V11N11 (Aug 2008)
        • V11N12 (Sep 2008)
      • Volume 12
        • V12N1 (Oct 2008)
        • V12N2 (Nov 2008)
        • V12N3 (Dec 2008)
        • V12N4 (Jan 2009)
        • V12N5 (Feb 2009)
        • V12N6 (Mar 2009)
        • V12N7 (Apr 2009)
        • V12N8 (May 2009)
        • V12N9 (Jun 2009)
        • V12N10 (Jul 2009)
        • V12N11 (Aug 2009)
        • V12N12 (Sep 2009)
      • Volume 13
        • V13N1 (Oct 2009)
        • V13N2 (Nov 2009)
        • V13N3 (Dec 2009)
        • V13N4 (Jan 2010)
        • V13N5 (Feb 2010)
        • V13N6 (Mar 2010)
        • V13N7 (Apr 2010)
        • V13N8 (May 2010)
        • V13N9 (Jun 2010)
        • V13N10 (Jul 2010)
        • V13N11 (Aug 2010)
        • V13N12 (Sep 2010)
      • Volume 14
        • V14N1 (Oct 2010)
        • V14N2 (Nov 2010)
        • V14N3 (Dec 2010)
          • Ammunition
        • V14N4 (Jan 2011)
        • V14N5 (Feb 2011)
        • V14N6 (Mar 2011)
        • V14N7 (Apr 2011)
        • V14N8 (May 2011)
        • V14N9 (Jun 2011)
        • V14N10 (Jul 2011)
        • V14N11 (Aug 2011)
        • V14N12 (Sep 2011)
      • Volume 15
        • V15N1 (Oct 2011)
        • V15N2 (Nov 2011)
        • V15N4 (Jan 2012)
        • V15N5 (Feb 2012)
      • Volume 16
        • V16N1 (1st Quarter 2012)
        • V16N2 (2nd Quarter 2012)
        • V16N3 (3rd Quarter 2012)
        • V16N4 (4th Quarter 2012)
      • Volume 17
        • V17N1 (1st Quarter 2013)
        • V17N2 (2nd Quarter 2013)
        • V17N3 (3rd Quarter 2013)
        • V17N4 (4th Quarter 2013)
      • Volume 18
        • V18N1 (Jan Feb 2014)
        • V18N2 (Mar Apr 2014)
        • V18N3 (May Jun 2014)
        • V18N4 (Jul Aug 2014)
        • V18N5 (Sep Oct 2014)
        • V18N6 (Nov Dec 2014)
      • Volume 19
        • V19N1 (Jan 2015)
        • V19N2 (Feb Mar 2015)
        • V19N3 (Apr 2015)
        • V19N4 (May 2015)
        • V19N5 (Jun 2015)
        • V19N6 (Jul 2015)
        • V19N7 (Aug Sep 2015)
        • V19N8 (Oct 2015)
        • V19N9 (Nov 2015)
        • V19N10 (Dec 2015)
      • Volume 20
        • V20N1 (Jan 2016)
        • V20N2 (Feb Mar 2016)
        • V20N3 (Apr 2016)
        • V20N4 (May 2016)
        • V20N5 (Jun 2016)
        • V20N6 (Jul 2016)
        • V20N7 (Aug Sep 2016)
        • V20N8 (Oct 2016)
        • V20N9 (Nov 2016)
        • V20N10 (Dec 2016)
      • Volume 21
        • V21N1 (Jan 2017)
        • V21N2 (Feb Mar 2017)
        • V21N3 (Apr 2017)
        • V21N4 (May 2017)
        • V21N5 (Jun 2017)
        • V21N6 (Jul 2017)
        • V21N7 (Aug Sep 2017)
        • V21N8 (Oct 2017)
        • V21N9 (Nov 2017)
        • V21N10 (Dec 2017)
      • Volume 22
        • V22N1 (Jan 2018)
        • V22N2 (Feb 2018)
        • V22N3 (March 2018)
        • V22N4 (Apr 2018)
        • V22N5 (May 2018)
        • V22N6 (Jun Jul 2018)
        • V22N7 (Aug Sep 2018)
        • V22N8 (Oct 2018)
        • V22N9 (Nov 2018)
        • V22N10 (Dec 2018)
      • Volume 23
        • V23N1 (Jan 2019)
        • V23N2 (Feb 2019)
        • V23N3 (Mar 2019)
        • V23N4 (Apr 2019)
        • V23N5 (May 2019)
        • V23N6 (Jun Jul 2019)
        • V23N7 (Aug Sep 2019)
        • V23N8 (Oct 2019)
        • V23N9 (Nov 2019)
        • V23N10 (Dec 2019)
      • Volume 24
        • V24N1 (Jan 2020)
        • V24N2 (Feb 2020)
        • V24N3 (Mar 2020)
        • V24N4 (Apr 2020)
        • V24N5 (May 2020)
        • V24N6 (Jun Jul 2020)
        • V24N7 (Aug Sep 2020)
        • V24N8 (Oct 2020)
        • V24N9 (Nov 2020)
        • V24N10 (Dec 2020)
  • The Archive
    • Search The Archive
  • Store
    • Books
    • Back Issues
    • Merchandise
  • Events
  • About
    • About Small Arms Review
    • About Chipotle Publishing
    • Contact Us
    • Other Publications
      • Small Arms Defense Journal
  • Home
  • Articles
    • Guns & Parts
    • Suppressors
    • Optics & Thermals
    • Ammunition
    • Gear
    • News & Opinion
    • Columns
    • Museums & Factory Tours
    • ID Guides
    • Interviews
    • Event Coverage
    • Articles by Issue
      • Volume 1
        • V1N1 (Oct 1997)
        • V1N2 (Nov 1997)
        • V1N3 (Dec 1997)
        • V1N4 (Jan 1998)
        • V1N5 (Feb 1998)
        • V1N6 (Mar 1998)
        • V1N7 (Apr 1998)
        • V1N8 (May 1998)
        • V1N9 (Jun 1998)
        • V1N10 (Jul 1998)
        • V1N11 (Aug 1998)
        • V1N12 (Sep 1998)
      • Volume 2
        • V2N1 (Oct 1998)
        • V2N2 (Nov 1998)
        • V2N3 (Dec 1998)
        • V2N4 (Jan 1999)
        • V2N5 (Feb 1999)
        • V2N6 (Mar 1999)
        • V2N7 (Apr 1999)
        • V2N8 (May 1999)
        • V2N9 (Jun 1999)
        • V2N10 (Jul 1999)
        • V2N11 (Aug 1999)
        • V2N12 (Sep 1999)
      • Volume 3
        • V3N1 (Oct 1999)
        • V3N2 (Nov 1999)
        • V3N3 (Dec 1999)
        • V3N4 (Jan 2000)
        • V3N5 (Feb 2000)
        • V3N6 (Mar 2000)
        • V3N7 (Apr 2000)
        • V3N8 (May 2000)
        • V3N9 (Jun 2000)
        • V3N10 (Jul 2000)
        • V3N11 (Aug 2000)
        • V3N12 (Sep 2000)
      • Volume 4
        • V4N1 (Oct 2000)
        • V4N2 (Nov 2000)
        • V4N3 (Dec 2000)
        • V4N4 (Jan 2001)
        • V4N5 (Feb 2001)
        • V4N6 (Mar 2001)
        • V4N7 (Apr 2001)
        • V4N8 (May 2001)
        • V4N9 (Jun 2001)
        • V4N10 (Jul 2001)
        • V4N11 (Aug 2001)
        • V4N12 (Sep 2001)
      • Volume 5
        • V5N1 (Oct 2001)
        • V5N2 (Nov 2001)
        • V5N3 (Dec 2001)
        • V5N4 (Jan 2002)
        • V5N5 (Feb 2002)
        • V5N6 (Mar 2002)
        • V5N7 (Apr 2002)
        • V5N8 (May 2002)
        • V5N9 (Jun 2002)
        • V5N10 (Jul 2002)
        • V5N11 (Aug 2002)
        • V5N12 (Sep 2002)
      • Volume 6
        • V6N1 (Oct 2002)
        • V6N2 (Nov 2002)
        • V6N3 (Dec 2002)
        • V6N4 (Jan 2003)
        • V6N5 (Feb 2003)
        • V6N6 (Mar 2003)
        • V6N7 (Apr 2003)
        • V6N8 (May 2003)
        • V6N9 (Jun 2003)
        • V6N10 (Jul 2003)
        • V6N11 (Aug 2003)
        • V6N12 (Sep 2003)
      • Volume 7
        • V7N1 (Oct 2003)
        • V7N2 (Nov 2003)
        • V7N3 (Dec 2003)
        • V7N4 (Jan 2004)
        • V7N5 (Feb 2004)
        • V7N6 (Mar 2004)
        • V7N7 (Apr 2004)
        • V7N8 (May 2004)
        • V7N9 (Jun 2004)
        • V7N10 (Jul 2004)
        • V7N11 (Aug 2004)
        • V7N12 (Sep 2004)
      • Volume 8
        • V8N1 (Oct 2004)
        • V8N2 (Nov 2004)
        • V8N3 (Dec 2004)
        • V8N4 (Jan 2005)
        • V8N5 (Feb 2005)
        • V8N6 (Mar 2005)
        • V8N7 (Apr 2005)
        • V8N8 (May 2005)
        • V8N9 (Jun 2005)
        • V8N10 (Jul 2005)
        • V8N11 (Aug 2005)
        • V8N12 (Sep 2005)
      • Volume 9
        • V9N1 (Oct 2005)
        • V9N2 (Nov 2005)
        • V9N3 (Dec 2005)
        • V9N4 (Jan 2006)
        • V9N5 (Feb 2006)
        • V9N6 (Mar 2006)
        • V9N7 (Apr 2006)
        • V9N8 (May 2006)
        • V9N9 (Jun 2006)
        • V9N10 (Jul 2006)
        • V9N11 (Aug 2006)
        • V9N12 (Sep 2006)
      • Volume 10
        • V10N1 (Oct 2006)
        • V10N2 (Nov 2006)
        • V10N3 (Dec 2006)
        • V10N4 (Jan 2007)
        • V10N5 (Feb 2007)
        • V10N6 (Mar 2007)
        • V10N7 (Apr 2007)
        • V10N8 (May 2007)
        • V10N9 (Jun 2007)
        • V10N10 (Jul 2007)
        • V10N11 (Aug 2007)
        • V10N12 (Sep 2007)
      • Volume 11
        • V11N1 (Oct 2007)
        • V11N2 (Nov 2007)
        • V11N3 (Dec 2007)
        • V11N4 (Jan 2008)
        • V11N5 (Feb 2008)
        • V11N6 (Mar 2008)
        • V11N7 (Apr 2008)
        • V11N8 (May 2008)
        • V11N9 (Jun 2008)
        • V11N10 (Jul 2008)
        • V11N11 (Aug 2008)
        • V11N12 (Sep 2008)
      • Volume 12
        • V12N1 (Oct 2008)
        • V12N2 (Nov 2008)
        • V12N3 (Dec 2008)
        • V12N4 (Jan 2009)
        • V12N5 (Feb 2009)
        • V12N6 (Mar 2009)
        • V12N7 (Apr 2009)
        • V12N8 (May 2009)
        • V12N9 (Jun 2009)
        • V12N10 (Jul 2009)
        • V12N11 (Aug 2009)
        • V12N12 (Sep 2009)
      • Volume 13
        • V13N1 (Oct 2009)
        • V13N2 (Nov 2009)
        • V13N3 (Dec 2009)
        • V13N4 (Jan 2010)
        • V13N5 (Feb 2010)
        • V13N6 (Mar 2010)
        • V13N7 (Apr 2010)
        • V13N8 (May 2010)
        • V13N9 (Jun 2010)
        • V13N10 (Jul 2010)
        • V13N11 (Aug 2010)
        • V13N12 (Sep 2010)
      • Volume 14
        • V14N1 (Oct 2010)
        • V14N2 (Nov 2010)
        • V14N3 (Dec 2010)
          • Ammunition
        • V14N4 (Jan 2011)
        • V14N5 (Feb 2011)
        • V14N6 (Mar 2011)
        • V14N7 (Apr 2011)
        • V14N8 (May 2011)
        • V14N9 (Jun 2011)
        • V14N10 (Jul 2011)
        • V14N11 (Aug 2011)
        • V14N12 (Sep 2011)
      • Volume 15
        • V15N1 (Oct 2011)
        • V15N2 (Nov 2011)
        • V15N4 (Jan 2012)
        • V15N5 (Feb 2012)
      • Volume 16
        • V16N1 (1st Quarter 2012)
        • V16N2 (2nd Quarter 2012)
        • V16N3 (3rd Quarter 2012)
        • V16N4 (4th Quarter 2012)
      • Volume 17
        • V17N1 (1st Quarter 2013)
        • V17N2 (2nd Quarter 2013)
        • V17N3 (3rd Quarter 2013)
        • V17N4 (4th Quarter 2013)
      • Volume 18
        • V18N1 (Jan Feb 2014)
        • V18N2 (Mar Apr 2014)
        • V18N3 (May Jun 2014)
        • V18N4 (Jul Aug 2014)
        • V18N5 (Sep Oct 2014)
        • V18N6 (Nov Dec 2014)
      • Volume 19
        • V19N1 (Jan 2015)
        • V19N2 (Feb Mar 2015)
        • V19N3 (Apr 2015)
        • V19N4 (May 2015)
        • V19N5 (Jun 2015)
        • V19N6 (Jul 2015)
        • V19N7 (Aug Sep 2015)
        • V19N8 (Oct 2015)
        • V19N9 (Nov 2015)
        • V19N10 (Dec 2015)
      • Volume 20
        • V20N1 (Jan 2016)
        • V20N2 (Feb Mar 2016)
        • V20N3 (Apr 2016)
        • V20N4 (May 2016)
        • V20N5 (Jun 2016)
        • V20N6 (Jul 2016)
        • V20N7 (Aug Sep 2016)
        • V20N8 (Oct 2016)
        • V20N9 (Nov 2016)
        • V20N10 (Dec 2016)
      • Volume 21
        • V21N1 (Jan 2017)
        • V21N2 (Feb Mar 2017)
        • V21N3 (Apr 2017)
        • V21N4 (May 2017)
        • V21N5 (Jun 2017)
        • V21N6 (Jul 2017)
        • V21N7 (Aug Sep 2017)
        • V21N8 (Oct 2017)
        • V21N9 (Nov 2017)
        • V21N10 (Dec 2017)
      • Volume 22
        • V22N1 (Jan 2018)
        • V22N2 (Feb 2018)
        • V22N3 (March 2018)
        • V22N4 (Apr 2018)
        • V22N5 (May 2018)
        • V22N6 (Jun Jul 2018)
        • V22N7 (Aug Sep 2018)
        • V22N8 (Oct 2018)
        • V22N9 (Nov 2018)
        • V22N10 (Dec 2018)
      • Volume 23
        • V23N1 (Jan 2019)
        • V23N2 (Feb 2019)
        • V23N3 (Mar 2019)
        • V23N4 (Apr 2019)
        • V23N5 (May 2019)
        • V23N6 (Jun Jul 2019)
        • V23N7 (Aug Sep 2019)
        • V23N8 (Oct 2019)
        • V23N9 (Nov 2019)
        • V23N10 (Dec 2019)
      • Volume 24
        • V24N1 (Jan 2020)
        • V24N2 (Feb 2020)
        • V24N3 (Mar 2020)
        • V24N4 (Apr 2020)
        • V24N5 (May 2020)
        • V24N6 (Jun Jul 2020)
        • V24N7 (Aug Sep 2020)
        • V24N8 (Oct 2020)
        • V24N9 (Nov 2020)
        • V24N10 (Dec 2020)
  • The Archive
    • Search The Archive
  • Store
    • Books
    • Back Issues
    • Merchandise
  • Events
  • About
    • About Small Arms Review
    • About Chipotle Publishing
    • Contact Us
    • Other Publications
      • Small Arms Defense Journal
No Result
View All Result
Small Arms Review
No Result
View All Result
Home Product Review

SIG Sauer MCX SPEAR LT: Evolution of a Fighting Rifle

by Todd Burgreen
January 5, 2023
in Product Review
MCX SPEAR LT

The MCX SPEAR LT is an ergonomic, well-handling rifle. Drills moving around barricades clearly bore this out. (Todd Burgreen)

Share on FacebookShare on Twitter

By Todd Burgreen –

SIG Sauer is at it again. The company is recognized as an industry leader in the development and manufacturing of rifles, submachine guns, belt-fed machine guns, handguns, optics, suppressors, ammunition, and more. This leads us to SIG’s latest rifle offering—the MCX SPEAR LT. The MCX is a new approach to the carbine platform that blends caliber adaptability with feature configurability without sacrificing reliability.

One thing immediately came to mind when the MCX SPEAR LT was introduced. How could the SPEAR LT be worthy of supplanting the original 2015 MCX and its 2017 MCX Virtus successor? SIG took a raft of grief from the public for releasing the upgraded MCX Virtus with some consumers crying foul over their perceived role as platform beta testers. So, SIG releasing a third generation of the MCX is bound to irritate past generation MCX owners.

Firing the MCX SPEAR LT 5.56MM from the bench. The rifle proved to be a 1MOA or better performer. (Todd Burgreen)

In the end, though, SIG can’t be expected to stop developing the platform when faced with advances in technology and materials, as well as lucrative procurement opportunities that would drive the development of any platform forward.

In the end, SIG is willing to endure the criticism it might face for advancing the MCX platform with another generational release that further improves the carbine’s ability to adapt to a wider range of missions, as the SPEAR LT does.

According to SIG, the original MCX spawned from a SOCOM request to develop a 7-pound, compact multi-caliber adaptable rifle that would be predominantly operated suppressed. The same military input has driven all three MCX generations. All of the MCX-series improvements were driven by additional tier one DOD unit contract requests that sought to increase accuracy, modularity, and durability. The public is fortunate to benefit with MCX civilian models made available.

100 yard 3-shot groups while performing scope adjustment evaluations with the SIG Tango-MSR LPVO 1-6x24mm optic. Ammunition used was SIG SAUER 77-grain OTM. Suppressor is the SIG SLH. (Todd Burgreen)

Inevitable Evolution

“The MCX SPEAR LT is an evolution of the MCX VIRTUS,” says SIG Sauer’s Media Relations Manager Michael Marotte, “brought about through competition in U.S. Special Forces and allied special forces weapons contracts.”

Addressing the differences between MCX Virtus and MCX SPEAR LT, Marotte says, “Externally the biggest difference is the handguard, we went lighter and slimmer and thus more ergonomic. Doing this typically sacrifices the rigidity needed for laser aiming modules, however we have maintained the rigidity by adding two retention screws that attach the handguard directly to the upper receiver.”

SIG MCX SPEAR LT with SIG SLH 7.62 suppressor and SIG Tango-MSR LPVO 1-6x24mm optic. With the SIG MCX SPEAR LT, SIG displays its market dominance as a total system provider. (Todd Burgreen)

He says the second large difference is the addition of an ambidextrous bolt-catch and bolt-release on the right side of the firearm. Push up to lock the bolt to the rear or down to release it.

The folding stock and modularity are big indicators that the MCX is not another AR platform. The MCX bolt carrier group is different than an AR’s. The initial user’s request to use a folding stock in lieu of a typical AR buffer tube setup required a new bolt carrier design. SIG installed dual recoil springs above the bolt carrier group. Due to the recoil spring placement, the charging handle sits slightly higher on the MCX receiver compared to an AR. Not only did the dual recoil springs enable the use of a folding stock, but it provides other benefits in terms of a smoother and softer recoil impulse, elimination of buffer tube wear associated with AR piston driven rifles, and an increase in overall reliability and durability. The intent to operate almost exclusively suppressed and to accommodate various calibers using different barrel lengths (including sub-10-inch barrels) meant the MCX would use a self-regulating, short-stroke operating system.

Generations

SIG’s designers needed to meet a 50,000-round-count endurance criteria for the upper receiver to satisfy the initial solicitation that brought the MCX to life. The MCX Virtus takes this even further with a 20,000-round endurance requirement that excludes replacing normal wear and tear components during the endurance test. This should allay any concerns about its durability in terms of wear and “loosening” up with use. The MCX SPEAR LT follows this path.

Obviously, quality materials are a must along with a full understanding of high wear parts on the rifle. SIG has designed the MCX with certain key components upgraded from aluminum to steel; these parts are also easily replaceable. For example, the cam path and feed ramp inserts. The charging handle latches move over steel pins as opposed to aluminum pins. MCX barrels are hammer forged and receive a nitride treatment for increased barrel life.

The original MCX to MCX Virtus improvements consisted of a tapered lug bolt group, a two-stage SIG Matchlite Duo trigger, thicker receivers and barrels (the reason why MCX and MCX Virtus barrels and bolt groups are not interchangeable), M-Lok handguard and modified gas port locations. The MCX SPEAR LT ups the ante even further over the MCX Virtus. SIG’s Marotte points out that with the SPEAR LT, “the bolt carrier group has had a minor redesign, moving the firing pin safety latch from the 12 o’clock position in the recoil assembly to a 9 o’clock position on the carrier. This reduces the energy needed to defeat the latch, allowing for the use of aftermarket AR triggers. It also improves performance and reliability with surplus, hard primer 7.62×39 ammo.”

The SPEAR LT has a lightened and recontoured handguard with attachment screws for additional rigidity. Barrel manufacturing focused on maintaining accuracy, even with the SPEAR LT’s slimmer profile barrel. About a pound was shaved off the MCX SPEAR LT compared to MCX Virtus. Other features of the MCX SPEAR LT include an ambidextrous bolt catch and bolt release on its lower receiver. The MCX SPEAR LT is fully ambidextrous—selector switch, charging handle, bolt, and magazine release. A lever on the right side of the receiver above the magazine release acts as a supplemental bolt catch and bolt release.

The MCX SPEAR LT features coyote anodized finish, including minimalist stock with button release for maximum compact foldability. The return to AR15-style trigger compatibility will be well received. The MCX SPEAR LT brings the long-anticipated addition of the 7.62×39 caliber to the MCX family.

Modularity

The rifle’s caliber, barrel length, forend, and buttstock are all easily interchangeable. Anecdotal stories are shared by SIG representatives of how the SIG MCX would be submitted for certain military solicitations with all associated gear arriving in one hard case. We’re talking about different calibers, barrel lengths, handguards, optics, and suppressors—all made by SIG, by the way. We’re told that in these situations, competitors would be wheeling in multiple cases of gear and setting up multiple upper receiver configurations to meet the desired trial parameters instead of just switching out specific components as needed.

The MCX bolt carrier group differs from that of an AR because. It contains dual recoil springs above the bolt carrier group to accommodate the MCX SPEAR LT’s folding stock. (Todd Burgreen)

The SIG MCX SPEAR LT can be viewed as a fresh design in a market dominated by the AK and the AR. The SIG MCX represents a new age of rifle modularity. Caliber change between 5.56mm and 300AAC is a simple matter. The fact that the 5.56mm and 300AAC share the same magazine and bolt group is the foundation for their close compatibility. Removing the forend exposes two captive T27 Torx bolts. Loosening these allows the barrel and gas piston to be removed. The new barrel and gas piston is then installed with the two T27 Torx bolts tightened to 60-inch pounds. The whole process is as simple as reading it. Caliber changes between 5.56mm/300AAC and 7.62×39 require a bolt change and the barrel kits will come with the bolt.

Ancillary Support

A SIG SLH 7.62 suppressor was chosen for use with the MCX SPEAR LT. SIG’s SLX/SLH QD muzzle device arrives pre-installed on the MCX SPEAR LT. The SLH uses SIG’s new clutch-LOK QD mounting system. SIG has put as much thought into the SLH 762 suppressor as the SPEAR LT. Not only is hearing protection addressed with the SLH, but so is th4 management of toxic fumes associated with back blast. MIT computing power was purchased to come up with a monolithic baffle design to keep fumes out of the operator’s face. Traditional CNC machining could not cope with the intricate metal work needed to comply with the blueprint, so 3D printing and DMLS manufacturing methods are used. The SLH remained mounted on the SPEAR LT for the majority of our evaluation.

The SIG theme was continued with a SIG Tango-MSR LPVO 1-6x24mm optic. The MSR LPVO offers a 1x illuminated reticle setting for quick target acquisition at close range with both eyes open. A quick turn of the eyepiece to 6x enables longer precision shots. The optic is loaded with high end features such as an adjustable illuminated BDC6 MOA reticle, and low dispersion, high transmittance glass for outstanding light transmission and clarity.

We ran several different types of mags with the SIG MCX SPEAR LT including the U.S.-made Sentry Hexmag carbon fiber 20- and 30-rounders. (Todd Burgreen)

The MCX SPEAR LT handguard’s M-LOK capability allows mounting Crimson Trace’s recently introduced RIG (Rapid Illumination Grip). The RIG combines the ergonomic advantage of an angled foregrip with a 500-peak-lumen weapon light into one sleek, effective device. As a side note, the RIG is ideal for braced pistols requiring a light. The angled foregrip is not considered a vertical foregrip which is a big no-no on braced pistols due to Federal regulations.

Ammunition tested with the SIG MCX SPEAR LT was a combination of multiple 5.56mm/223Rem loads from SIG, Black Hills, and Hornady. No load tested produced greater than 1.5-inch groups at 100 yards. Our top performer, SIG’s Elite 77 grain Match punched three rounds into a 0.5-.75-inch groups. Pretty impressive considering the 1-6x optic mounted and the idea that the MCX SPEAR LT is a fighting rifle, not a match target rifle affair, making this performance even more impressive.

PERFORMANCE

LOADVELOCITY AVG.ACCURACY (Avg.@100yd)
Black Hills 69gr Match2705fps1in
Hornady 55gr TAP2935fps1.33in
SIG Sauer 77gr OTM2731fps0.75in
American Eagle 62gr FMJ2980fps1.66in

RANGE EVALUATION

The minimalist nature of the SIG folding stock caused some initial skepticism related to the rifle’s ergonomics and effectiveness. This was quickly forgotten once the shooting started. The folding stock proved rock solid and provided a solid cheek weld for use with optics; kudos to the SIG design team for this. The MCX SPEAR LT lived up to the task of being an ergonomic, well handling rifle. Drills moving around barricades and training evolutions involving firing and evacuating from vehicles clearly bore this out. The handy MCX is what individuals will choose to work with in such environments. Over 500 rounds were fired for this T&E. The piston driven MCX proved utterly reliable with only minimal effort given to wipe down bolt carrier group and lubricate sporadically.

Training with the MCX SPEAR LT at Echo Valley Training Center. (Todd Burgreen)

The SIG short-stroke gas piston operating rod system proved its worth, keeping the bolt carrier group cooler and cleaner compared to direct impingement rifles, even with the SIG SLH suppressor mounted. While not trying to be unrealistic or overly harsh, the SIG MCX was exposed to a high volume of fire typical of team tactics bounding drills. The method was employed to confirm that, beyond a doubt, the SIG MCX delivered as advertised under the most adverse operational conditions, including with a suppressor mounted. A Magpul PMAG D-60 drum magazine was used during portions of our evaluation. This allowed the MCX SPEAR LT to shine when faced with a harsh, no-breaks firing schedule. We appreciated how well the MCX SPEAR LT forend shielded the shooter’s off-hand from the heat coming off the barrel. The Crimson Trace RIG also held up well under the semi-abusive environment.

With the SIG MCX SPEAR LT, SIG finds itself in an advantageous position by being a total system provider — weapons, optics, suppressors, ammunition, and other accessories. At the beginning of this article, I openly questioned if the new, third generation MCX SPEAR LT was really necessary. The real shame would have been if the improvements represented in the MCX SPEAR LT had been withheld. Performance is the quickest way to appeal to the shooting public…the MCX SPEAR LT will have no problem proving its worth.

SPECIFICATIONS

Make:SIG Sauer
Model:MCX SPEAR LT
Caliber:5.56mm, as tested (300BLK, 7.62×39 available)
Barrel:16in 1:7in (other lengths available)
Overall Length:34.3in (stock extended)
Weight:7.5lb
Action:Short-stroke, Gas-piston
Capacity:30rd AR-style Mags
MSRP:$2799
URL:sigsauer.com
The M-Lok- mounted RIG from Crimson Trace combines the ergonomic advantage of an angled foregrip with a 500-peak-lumen weapon light into one effective device. (Todd Burgreen)
Tags: MCXRifleSIG SauerSOCOMSPEAR
Previous Post

Narrow Variables Increase Accuracy: How to Avoid Negative-Accuracy Sins

Next Post

Troubleshooting the Atchisson Type AR15/M16 .22 Conversion Kits

Next Post
Troubleshooting the Atchisson Type AR15/M16 .22 Conversion Kits

Troubleshooting the Atchisson Type AR15/M16 .22 Conversion Kits

TRENDING STORIES

  • VALKYRIE ARMAMENT BELT-FED CONVERSION

    VALKYRIE ARMAMENT BELT-FED CONVERSION

    0 shares
    Share 0 Tweet 0
  • EAST GERMAN WIEGER STG RIFLE

    0 shares
    Share 0 Tweet 0
  • The Complete Guide To Colt M-16 Models: Part I

    0 shares
    Share 0 Tweet 0
  • Forgotten M16A1 Rifle Manufacturers: GM/Hydra-Matic and Harrington & Richardson – Part I

    0 shares
    Share 0 Tweet 0
  • The Second Generation AR57: Drop-in 5.7 Upper For Your AR

    0 shares
    Share 0 Tweet 0

RECENT POSTS

SIG Sauer’s Full-Size Compact P365 “Fuse”

SIG Sauer’s Full-Size Compact P365 “Fuse”

June 27, 2024
The Importance of Offhand Shooting

The Importance of Offhand Shooting

June 25, 2024
BOOK REVIEW – The Collector’s Guide to the SKS

BOOK REVIEW – The Collector’s Guide to the SKS

June 20, 2024
True to Form: The Tisas 1911A1 ASF

True to Form: The Tisas 1911A1 ASF

June 18, 2024
Setting the Record Straight on the Fedorov Avtomat

Setting the Record Straight on the Fedorov Avtomat

June 6, 2024

QUICK LINKS

  • About Chipotle Publishing
  • About Small Arms Review
  • Advertise with Us
  • Write for Us

CONTACT DETAILS

  • Phone: +1 (702) 565-0746
  • E-mail: office@smallarmsreview.com
  • Web: www.chipotlepublishing.com
  • Chipotle Publishing, LLC 631 N. Stephanie St., No. 282, Henderson, NV 89014
Small Arms Review

FOLLOW US

  • Privacy Policy
  • Disclaimer

© 2022 Chipotle Publishing | All Rights Reserved

Welcome Back!

Login to your account below

Forgotten Password?

Retrieve your password

Please enter your username or email address to reset your password.

Log In

Add New Playlist

No Result
View All Result
  • Home
  • Articles
    • Guns & Parts
    • Suppressors
    • Optics & Thermals
    • Ammunition
    • Gear
    • News & Opinion
    • Columns
    • Museums & Factory Tours
    • ID Guides
    • Interviews
    • Event Coverage
    • Articles by Issue
      • Volume 1
      • Volume 2
      • Volume 3
      • Volume 4
      • Volume 5
      • Volume 6
      • Volume 7
      • Volume 8
      • Volume 9
      • Volume 10
      • Volume 11
      • Volume 12
      • Volume 13
      • Volume 14
      • Volume 15
      • Volume 16
      • Volume 17
      • Volume 18
      • Volume 19
      • Volume 20
      • Volume 21
      • Volume 22
      • Volume 23
      • Volume 24
  • The Archive
    • Search The Archive
  • Store
    • Books
    • Back Issues
    • Merchandise
  • Events
  • About
    • About Small Arms Review
    • About Chipotle Publishing
    • Contact Us
    • Other Publications
      • Small Arms Defense Journal

© 2022 Chipotle Publishing | All Rights Reserved

This website uses cookies. By continuing to use this website you are giving consent to cookies being used. Visit our Privacy and Cookie Policy.

Redirecting to External Website

You are leaving the Small Arms Review website and will be redirected to an external link in a 5 Seconds.
VISIT NOW!