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
  • Podcast
  • Newsletter
  • Events
  • FrankenGun Challenge
  • 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
  • Podcast
  • Newsletter
  • Events
  • FrankenGun Challenge
  • 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 Articles

LM-7:BELT-FED AR-15/M16 IN .22LR: THE RADICAL NEW RIMFIRE FROM LAKESIDE MACHINE

SAR Staff by SAR Staff
August 2, 2022
in Articles, Articles by Issue, Search by Issue, V9N7 (Apr 2006), Volume 9
LM-7:BELT-FED AR-15/M16 IN .22LR: THE RADICAL NEW RIMFIRE FROM LAKESIDE MACHINE
Share on FacebookShare on Twitter

Text & Photos by Jeff W. Zimba

The masters of the miniature machine guns have just unveiled their latest creation. In just over a year, from concept to production, Lakeside Machine of Pound, Wisconsin has announced the addition of the LM-7 to their rimfire lineup. The LM-7 is a belt-fed upper receiver chambered in .22 long rifle for an M16 or AR-15 type rifle.

During the ten year period of the Clinton Assault Weapons ban (1994-2004), common firearms that were deemed “assault weapons” were prohibited from manufacture for sale to individuals. Also prohibited were magazines and feeding devices with a capacity greater than ten rounds. This resulted in a cessation of many innovative projects and caused a sharp increase in price for existing supplies of weapons and magazines. There were many new weapon concepts and pioneering ideas during this time, but with a market limited to the military and law enforcement, economically, there was little point in proceeding. With the expiration of the Clinton Assault Weapons ban in 2004, firearm design and ingenuity has reemerged after being stifled for ten years and new designs and products are hitting the market at an amazing pace.

Firing sequence – The extractor pulls a round from the belt. As the bolt travels to the rear the round is pushed downward on the T-slot in the bolt. When the bolt returns to the front, the round is chambered as the extractor collects the new round for belt extraction. As the process is repeated, the new round being pushed down the T-slot forces the fired round further down and out the ejection port.

Lakeside Machine has been in the business of manufacturing high capacity rimfire guns since their purchase of Tippmann Arms from F.J. Vollmer and Company in September, 2001. They initially specialized in the manufacture and sales of the one-half scale miniature Tippmann machine guns (Small Arms Review – Vol. 7 No. 6, March 2004). As the 2004 sunset of the ban got closer, their focus switched to a line of newly designed, shoulder-fired variants. Although the firearms could be manufactured in compliance with the ban, the limited availability of belts for feeding them was very poor. With the ban terminated, more belt material was able to be manufactured and a new generation of belt-fed rimfire rifles was born.

The first shoulder fired, belt fed rifle system designed by Lakeside Machine was the BF1 Vindicator (Small Arms Review – Vol. 8 No. 4, January 2005). Introduced in 2004, these rifles were manufactured in .22 Long Rifle with a few chambered in the relatively new .17 Mach II. These rifles used the same cloth belts originally designed for the Tippmann miniature machine guns and can also use the newly designed disintegrating links; another one of Lakeside Machines’ recent innovations. The disintegrating links are made of a Nylon material and function with .22LR, .22 Magnum, .17 HMR and .22 Mach II. These links have been upgraded by impregnating them with enough metal content to allow them to be picked up with a magnet.

In October of 2004, Eric Graetz, CEO of Lakeside Machine was approached by a customer and asked if he thought he could design an AR-15/M16 upper receiver that would accept his belts and links. Graetz accepted the challenge. After some months of research and development, the machine shop was retooled to manufacture the latest creation: the LM-7 .22LR (and .17 Mach II) belt-fed upper receiver. The prototype was unveiled in December of 2004 at the SAR Show in Phoenix, Arizona.

The LM-7 (the 7th model firearm developed by Lakeside Machine) is a complete upper receiver assembly that will fit on any standard AR-15 or M16 lower receiver and function with the trigger internals as intended. While offered in a semiautomatic configuration, an upgrade is available so the upper will function in full automatic when used on a registered full automatic lower receiver. To the delight of the NFA community, it will also work in conjunction with a drop-in auto sear.

Mounting the LM-7

Before replacing the stock upper receiver with an LM-7, the factory buffer and spring must be removed from the lower receiver and replaced with the new buffer assembly supplied with the LM-7. The factory hammer spring should also be replaced with a much lighter hammer spring that is also supplied with the LM-7. That is the extent of the modifications to the lower receiver when used on a semiautomatic rifle. When used on a full automatic rifle there are a few timing adjustments that may be necessary and will be discussed later in this article.

Installing the LM-7 upper receiver is as simple as pulling the two takedown pins, removing the factory upper and replacing it with the LM-7 upper receiver. Once pinned on the lower receiver, the factory magazine-well now functions as a brass ejection port. In order to catch the ejected casings, Lakeside Machine supplies a brass catcher that locks into the magazine-well in the same manner as a factory magazine. As it fills to capacity it can simply be “ejected” like a standard magazine, the contents dumped out, and quickly reinserted. The bottom of the brass catcher also has a swing-down floor plate to allow empty brass to flow through when the shooter does not want to retain the ejected casings. The brass catcher doubles as an attachment platform for the optional belt box and link catcher. Shooting long belts without the assistance of an A-Gunner can easily be accomplished with the use of the belt feed box. It holds a little more than 200 belted or linked rounds. Since the links are ejected directly across from the feed tray, another identical box mounted on the opposite side of the feed box catches all the used links.

The LM7 has a newly developed quick change barrel system. To change barrels the user simply pushes the barrel release (arrow) and pulls the barrel straight out. To insert a new barrel, the button is depressed and the barrel is simply pushed in.

The LM-7 functions in a similar fashion to a Browning Model 1919 machine gun. It utilizes a shuttle feed mechanism that feeds the belt, extracts each round from the rear of the belt, chambers the round and extracts the empty case after firing. This mechanism does not utilize a locked action. The rifle is loaded by lifting the top cover and inserting the belt with the first round placed below the extractor. The top cover is closed and the gun is charged by pulling the bolt handle back and released one time. As a new round is pulled from the belt and loaded in the chamber the fired case is pushed out of the T-slot in the bolt and dropped into the brass box or directly on the ground.

The LM7 recoil assembly replaces the factory buffer and buffer spring. The same assembly is used for both carbine and full-length stocks in conjunction with the correct length spacer supplied by Lakeside Machine.

The LM-7 utilizes an exclusive quick-change barrel (QCB) that can be replaced in seconds. Changing or installing a barrel is as simple as depressing the barrel release button, pulling the barrel strait out, replacing the barrel and releasing the button. It is a direct action that requires no twisting, turning, adjusting or head spacing. Barrels are currently available in two lengths and three styles. Barrel lengths are 16.25 inches and 7.5 inches. The 16.25-inch barrels are contoured just like a standard M4 barrel and can utilize any of the M4 mounting options. Where the barrels are secured in the receiver by the QCB mechanism, they are completely free-floating and will work fine with any free-floating style handguard. If you wish to use standard M4 handguards you can utilize an adapter that secures them at the front and also doubles as a front sight block. Where it is unnecessary for the front of the barrel to be supported by any handguard mounting hardware, it lends itself well to the use of shorter barrels with sound suppressors. The 7.5-inch barrel we were shooting with was often fitted with an AWC MKII suppressor that protruded less than 4 inches past the standard carbine handguards. If this system were going to be set up in this configuration for regular use, the handguard would certainly be replaced with a free-floating type or any of the rail systems allowing the use of various accessories.

On the rear of the top cover is a 4.25-inch M1913 Picatinny rail to accept short optics or a removable rear sight. The front block installed with a 16-inch barrel includes a 1.75-inch rail that can host standard removable front sights and accessories. The LM-7 we tested was equipped with an EO Tech Model 552 Holographic Sight. While the version using AA batteries was a little long on this mount, it was certainly still usable. While using the sight with multiple quick-change barrels, we noticed very little point of impact change. Each LM-7 system is shipped with the LM-7 Buffer System, a 16.25-inch barrel, front sight block, brass catcher, two feed boxes, two 100-round belts and 200 links.

The brass catcher installed with a pair of mounted belt boxes. The box placed on the left holds the loaded belts allowing the shooter to fire long belts without the assistance of an A-Gunner. The box mounted on the right side functions as a link catcher, extremely useful when using the new Lakeside Machine links instead of the cloth belts.

Rimfire Ammo Reliability

When the LM-7 was designed, it was built to function with the inexpensive CCI Blazer ammunition. This is fantastic news for shooters who are conscientious about their ammo budget. We tested the LM-7 with several types of .22LR ammunition and have included a chart indicating performance, muzzle velocity and rate of fire when utilized in full automatic. The ammunition we tested included CCI Blazer, CCI Mini-Mag, CCI Stinger, Remington Thunderbolt, Federal Lightning, Federal Bulk Pack, Federal Champion, and Winchester Wildcat. It ran fine with most but the Federal Champion was the least reliable. The absolute best was the CCI Stinger due to the increased power over standard .22LR ammo but the additional cost (almost $4.00 for a box of 50) may be enough to discourage many people. The Winchester Wildcat, Federal Lightning and CCI Blazer all worked great. The Federal Bulk Pack and Remington Thunderbolt also worked quite reliably. For some reason it was a little finicky with the CCI Mini-Mags. The author has found after years of shooting select-fire rimfire rifles and pistols, that when determining which .22LR ammo will work the best, it is usually a good idea to just try several brands in your own firearm. Some seem to run great with one particular brand while other firearms like something completely different. Factors that may be important in the LM-7 that would not necessarily be an issue in other .22LR guns include the thickness of the rim. After extraction from the belt, the round is channeled down a T-slot to the chamber, and captured in the T-Slot again as it is channeled down to the point of ejection. If a particular brand or batch of ammo has a thicker than usual rim, it could interfere with, or stop, the operation of the gun altogether.

The complete LM7 system includes the new upper receiver, a 16-inch barrel, the front sight block, carbine length handguards, LM7 bolt and bolt handle, LM7 recoil assembly and both recoil assembly spacers.

The greatest obstacle in reliable functioning is the lack of energy in the little .22LR cartridge. It takes a lot of energy to run these machines in full automatic and when you start adding factors like pulling belts and links, the challenge gets even greater. Light parts and springs, necessary because of the low amount of energy created by the rimfire round, only add to bolt bounce problems and pose additional hurdles in the development of select-fire, Rimfire guns. Unlike many other select-fire .22 LR firearms, bolt bounce is not a problem in the LM-7 due to the function of the extractor pulling the new round from the belt at the same time the chambered round is fired. This action dampens the rearward travel of the bolt and eliminates the bolt bounce issue.

A brass catcher is included with every LM7. It is simply inserted in the mag-well in the same manner as a standard M16 magazine. It is removed by depressing the magazine release button. As well as catching the empty brass it also serves as a mounting platform for the belt box and link catcher.

Timing and Function in Full Automatic

With the weak .22LR ammo in mind, we can get into some of the timing issues when shooting the LM-7 in full automatic. Subtle inconsistencies that are not critical dimensions with higher-powered rounds can often be the determining factor in creating problems when shooting rimfire rifles. In the case of the LM-7, some of the loose tolerances of standard 5.56mm guns combined with the fact there are several manufacturers of rifles, receivers and parts to fill them, create an enormous number of potential combinations.

When shooting the LM-7, the trigger function is identical to that of the original 5.56mm rifle. While shooting in semiautomatic mode, when the bolt carrier recoils from shooting the chambered round, the hammer is cocked and held captive by the disconnector. When the shooter lets off the trigger the hammer releases from the disconnector and engages the front of the trigger. When the shooter squeezes the trigger the hammer is released and the process starts all over again. When shooting in full automatic mode, the hammer bypasses the disconnector and does not contact it at all. A spur on the back of the hammer is caught and held captive by the auto sear and it is only released when the bolt carrier trips that sear when the gun has chambered the new round and it is in battery. The timing aspect comes into play with the relationship between the bolt carrier sear trip and the sear releasing the hammer.

The part of the LM-7 that has to be altered for full automatic fire is the bolt carrier. Just like the standard AR-15 and M16, all that is necessary for the upper receiver to accommodate a legally owned full automatic lower receiver, is the addition of a sear trip on the carrier. Lakeside Machine will be happy to provide owners of registered receivers or drop in auto sears with the piece needed to engage the auto sear. That is where the timing comes into play. The sear trip on the carrier needs to contact the auto sear at the precise time the new round is fully chambered. Due to the large number of parts and receivers on the market, one gun may need a specific thickness on the sear trip to engage the sear at the correct time while another gun needs one much thicker. This timing can be accomplished by simply removing an Allen-head screw, removing the sear trip, adding a piece of shim material (an old feeler gauge set works great for shimming) and replacing the trip and screw. When the hammer drops at the same time the bolt completely closes it is ready to go.

Scaled down ammo boxes are available for the LM7, and can be used to store linked or belted ammo for any of the Lakeside Machine offerings.

Early in the testing we realized the tolerance difference in some hammers also created a problem where the guns would not cock the hammer far enough to catch it under the auto sear. This would cause the hammer to follow the carrier back into battery without firing it. Some of the hammer spurs were much thicker and/or longer than others. The cause of the problem was the lower power of the .22LR ammo was sending the much lighter bolt carrier back much slower than a standard 5.56mm carrier and not getting the hammer to fall back far enough. The reason this is not usually a problem with the 5.56mm round is because the mass of the carrier and the speed it is recoiling at is much greater than that of the LM-7. Lowering the internals of the entire LM-7 system so the hammer would drop much lower and not rely on speed, but simply movement, solved this issue.

Loading Belts

If there is any downfall to shooting belt fed firearms it is the simple fact that we have to load belts before we can shoot them. Lakeside Machine has helped us out a little in this area with the introduction of their new belt-loading device. A box of ammo, or small handful if you have bulk ammo, is dumped into the sorting hopper. A few shakes of the wrist and several are all lined up protruding from a small slot in the bottom of the device. A transfer bar is pushed up through the slot, catching the already lined up ammo, and slid out the front of the hopper. The transfer bar is then inserted into a loading block and the result is 10 rounds, all perfectly spaced and ready to be belted. When the belt is pushed over the rounds in the loading block they are all perfectly spaced and seated to the correct depth when the belt is removed. Several loading blocks can even be connected in unison to speed up the process. The author uses 3 blocks mounted together and has found that to be fast and comfortable. Since new belts are very tight the first time they are loaded, there is a spike that acts as a belt spreader included with the loading tool that can be mounted with the loading blocks. A simple pass through each pocket prior to loading each first round and it is no longer a struggle. No more blistered fingers from loading new belts and more time shooting instead of loading. As previously mentioned, you can also use disintegrating links instead of the cloth belts. These are much easier to load but don’t tend to hold the linked ammo quite as secure as the cloth belts do. Some people have found that given a slight pinch while loading them creates a little tighter hold. Both belts and links provide excellent results at the range. The 8-piece belt loading system is available for $40 and should be mandatory equipment for anyone who owns one of the Tippmann miniatures, a Vindicator Carbine or an LM-7.

The belt loading set makes the loading of belts much easier. 1) The hopper holds a full box of .22LR ammo. It is just dumped in and the cover closed. 2) With your finger over the front slot, shake the hopper back and forth a few times and the ammo falls down and aligns itself in the loading slot. 3) Using the transfer bar, line up the first round and push the bar up into the slot of the hopper. Slide the transfer bar forward out the slot, and it will be filled with 10 rounds. 4) Line the transfer bar up with a loading block and tip it upside down. The loading block will then be filled with ammo, perfectly spaced at the correct depth for placement in the belt. 5) If you are filling a new belt, run each loop over the spike to stretch it out. 6) The stretched loop will easily drop over a round in the loading block. 7) To check the belts for proper depth before firing, it may be inserted into a series of loading blocks and seated into proper placement.

BATFE Technology Branch Ruling

Unlike many other manufacturing projects, there was still something necessary even when the majority of the in-house troubleshooting had been completed. The Technology Branch of the Bureau of Alcohol, Tobacco Firearms and Explosives makes legal determinations on new firearms and related accessories based on samples submitted. They examine these new designs and based on the item submitted they will issue a determination in writing. There have been other designs submitted for determination changing the caliber and/or feed mechanism of specific firearms, where the devices were ruled firearms of themselves. There have been other designs where Technology Branch has determined the new device was too easily convertible to full automatic fire and ruled as machine guns, themselves. For obvious legal reasons a sample LM-7 was submitted to ATF and on December 6, 2005 it was determined that the LM-7 does NOT meet the definition of a firearm or a machine gun, and is simply an upper receiver, like countless other replacement upper receivers on the market.

Range Performance

Most of the range time was during sub-freezing temperatures at our production office in Maine. The LM-7 ran perfect in semiautomatic mode right from the box. In order to achieve reliable performance in full automatic, it had to be timed. This can be accomplished in less than an hour with the right materials and depending on the firearm you have, it may not involve any adjustments at all. As explained above, during preliminary testing we discovered several variables in most lower receiver fire control groups that had to be tweaked, and at this point Lakeside Machine has already addressed them in their new production models. Once we had everything adjusted and timed it ran excellent. We successfully ran several long belts just for function testing (ok, and a little fun) and fired several strings collecting data on muzzle velocity and rate of fire with several types of ammo in different configurations. The data from those tests are provided in the accompanying charts.

Conclusion

Lakeside Machine has hit a home run with this design. As an accessory for a military style firearm that has been the USA primary service weapon for over 40 years, there are a lot of host guns out there as potential customers. It is a reasonably priced way for a shooter to “upgrade” to a belt-fed firearm and it is a great way to shoot on a budget with the cheap price of most .22LR ammunition. It is fun to shoot and works excellent right out of the box in semiautomatic mode and, with a minimal amount of timing and fine-tuning, in full automatic. The conversion to LM-7 from a factory upper receiver is simple and can be completed in less than a minute. The vast number of accessories available for the LM-7, both from Lakeside Machine and current ones already on the market create an infinite number of configurations to suit any shooter. Where the LM-7 works in conjunction with previously owned, registered M16s and drop-in auto sears, it is about as close to having a “new” machine gun as we can get since May 19, 1986. There will always be room in this writer’s reference collection for an LM-7.

Sources

LM-7 Upper Receiver
Lakeside Machine
N5391 County Road. S.
Pound, WI 54161
Phone: (920) 897-4682
Fax: (920) 897-4688
www.lakesideguns.com

PACT Timers
PACT Inc.
Dept. SAR
P.O. Box 535025
Grand Prairie, TX 75053
(800) 722-8462
www.PACT.com

LM-7 Specifications Chart

Caliber: .22 Long Rifle
Overall Length: 24.5 inches w/16.25 inch barrel
Barrel Length: 16.25 inches & 7.5 inches
Weight: 5.05 pounds w/16.25-inch barrel
Barrel Rifling: 6-groove, right hand, 1 in 12 inches
Firing Mode: Semiautomatic and select fire
Method of Operation: Closed bolt, blowback action
Finish: Manganese phosphate
Rear Sights: M1913 Picatinny rail
Price: $1,750 suggested retail
.22 Long Rifle Muzzle Velocity Barrel Length
Ammunition
7.5-inches
w/flash hider
7.5-inches
w/sound suppressor
16.25-inches
w/flash
hider
16.25-inches
w/sound suppressor

Remington Thunderbolt
997fps
1,032fps
1,095fps
1,088fps

CCI Mini Mag
975fps
1,027fps
1,069fps
1,055fps

CCI Stinger
1,334fps
1,345fps
1,450fps
1,474fps

Federal Bulk Pack
1,064fps
1,054fps
1,139fps
1,148fps

Federal Champion
1,111fps 1,141fps 1,179fps 1,206fps

Measurements recorded 8 feet in front of the muzzle with a PACT MKIV Timer & Chronograph

.22LR Rate of Fire
Barrel Length
Ammunition
16.12-inches
w/flash hider
16.25-inches
w/sound suppressor

Remington Thunderbolt
970rpm
1,025rpm
CCI Mini Mag
1,046rpm
1,036rpm

CCI Stinger
1,076rpm
1,085rpm

Federal Bulk Pack
975rpm
N/A

Federal Champion
857rpm
857rpm

Measurements recorded with a PACT MKIV Timer & Chronograph.

This article first appeared in Small Arms Review V9N7 (April 2006)

Author

  • SAR Staff
    SAR Staff

    View all posts

Tags: 2006Belt fedJeff W. ZimbaLakeside GunsLM-7V9N7
Previous Post

RAFFICA

Next Post

RAFFICA

Next Post
RAFFICA

RAFFICA

TRENDING STORIES

  • U.S. NAVY MK18 MOD O CUSTOM CLOSE QUARTER COMBAT WEAPON FOR THE SEAFARING SERVICE

    U.S. NAVY MK18 MOD O CUSTOM CLOSE QUARTER COMBAT WEAPON FOR THE SEAFARING SERVICE

    0 shares
    Share 0 Tweet 0
  • Recreational Use Of 40MM Grenade Launchers

    0 shares
    Share 0 Tweet 0
  • Customizing the Already Custom SIG P320 Spectre Comp

    0 shares
    Share 0 Tweet 0
  • Col. Rex Applegate: The Knife Designs of a Close-Combat Legend

    0 shares
    Share 0 Tweet 0
  • Evolution of the U.S. Grenade Launcher From World War II to Today’s Conflicts

    0 shares
    Share 0 Tweet 0
  • Trending
  • Comments
  • Latest
U.S. NAVY MK18 MOD O CUSTOM CLOSE QUARTER COMBAT WEAPON FOR THE SEAFARING SERVICE

U.S. NAVY MK18 MOD O CUSTOM CLOSE QUARTER COMBAT WEAPON FOR THE SEAFARING SERVICE

Recreational Use Of 40MM Grenade Launchers

Recreational Use Of 40MM Grenade Launchers

SIG Spectre Comp with AXG Grip Module

Customizing the Already Custom SIG P320 Spectre Comp

Col. Rex Applegate: The Knife Designs of a Close-Combat Legend

Col. Rex Applegate: The Knife Designs of a Close-Combat Legend

New Review: V19N1

New Review: V23N3

SAR|Special

SAR|Special

The Grand Power Q100

The Grand Power Q100

A Fading Star: The star S135 Submachine Gun, That is

A Fading Star: The star S135 Submachine Gun, That is

The Iron Door: Soviet Russian Weapons Designers Stop the Germans in Their Tracks

The Iron Door: Soviet Russian Weapons Designers Stop the Germans in Their Tracks

The American FN FAL Rifle: In Search of the Perfect Lightweight Rifle

The American FN FAL Rifle: In Search of the Perfect Lightweight Rifle

Ahead of Its Time: British Fosbery Pump-Action Shotgun with “Stoner” Bolt

Ahead of Its Time: British Fosbery Pump-Action Shotgun with “Stoner” Bolt

The Big Bang! : Great American Fun at the 2018 Big Sandy Machine Gun Shoot in Wikieup, AZ

The Big Bang! : Great American Fun at the 2018 Big Sandy Machine Gun Shoot in Wikieup, AZ

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

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
  • Podcast
  • Newsletter
  • Events
  • FrankenGun Challenge
  • About
    • About Small Arms Review
    • About Chipotle Publishing
    • Contact Us
    • Other Publications
      • Small Arms Defense Journal

© 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

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

Subscribe To Our Weekly Newsletter

Are you in the know?
Stay up to date with the latest articles.

Facebook-f Linkedin Instagram

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!