Lewis Machine and Tool Company

Lewis Machine & Tool Company (LMT)[1] is an American armaments company. It was founded by Karl Lewis in 1980. LMT started its business by providing US law enforcement and government agencies with military type weapons and accessories. Subsequently they expanded to supply military and commercial retailers. All of LMT's engineering and manufacturing is done at their facility in Eldridge, Iowa. LMT manufactures complete weapon systems such as the M4/AR-15 and the M203 grenade launcher.[2] The militaries of the United Kingdom, New Zealand, Estonia and the United States use LMT products.

Lewis Machine and Tool Company
HeadquartersEldridge, Iowa, United States
ProductsFirearms, weapons
Number of employees
100-150[citation needed]


LM308MWS and CQB MRP DefenderEdit

LMT created the Monolithic Rail Platform (MRP),[3] a one-piece upper receiver for the AR-15/M4/M16 platform made from a forged aluminium block. The LMT MRP has a quad-rail system that utilizes the Mil-Std 1913 rail in two different lengths, one standard rifle length and the other for Close Quarters Battle (CQB).[4] The MRP upper receiver has a quick-change barrel system that allows the operator to change the caliber or the barrel length of the weapon in one minute.[5] The MRP also features a free-floating barrel, long barrel life, easy-to-access parts, a straight gas tube that resists bending and retains better alignment compared with other designs, and a relatively low number of parts (13). Also, its top rail position matches M4 and E3-type weapons, ensuring optical and sight compatibility, and accepts standard and enhanced M16-type (Stoner design) components.

In late 2009, LMT introduced the .308 Modular Weapon System LM308MWS.[6] The LM308MWS uses the 7.62×51mm NATO round. The LM308MWS is based on the proven Stoner Rifle design with some new features including the MRP upper receiver. An effective range of 800m and Sub-MOA grouping have been reported.

LMT is currently supplying 16", 18" and 20" 1:11¼" twist (rifling grooves complete one full revolution inside the bore every 11.25 inches) blackened stainless match barrels, as well as 16" and 20" chrome-lined chrome-moly 1:10" twist barrels for the civilian market.

In February 2012, the British Transport Police commenced patrolling with the CQB 10.5" SBR that may be fitted with a suppressor.[7][8][9]


TypeDesignated marksman rifle
Place of originUnited Kingdom
Service history
In service2010-Present
Used byBritish Armed Forces
New Zealand Army
WarsWar in Afghanistan
Production history
ManufacturerLewis Machine & Tool
Mass9.8 pounds (4.4 kg)

Cartridge7.62×51mm NATO
Barrels16 inches (410 mm)
Effective firing range800 m
Maximum firing range1000 m
SightsTA648-308 6×48 ACOG

In 2009, Lewis Machine & Tool Co was contracted to supply the British Ministry of Defence (MOD) with 440 LM308MWS 7.62×51mm rifles[10] under the official service designation as the L129A1.[11] As of December 2014, over 3,000 units have been supplied to UK forces.[12]

The LM308MWS was then submitted for the British MOD's Urgent Operational Requirement (UOR) for immediate deployment of a semiautomatic 7.62 NATO caliber sharpshooter rifle in Afghanistan. Other rifles submitted included the FN Herstal SCAR-H, Heckler & Koch HK417 and Sabre Defence XR-10. LMT's rifle was chosen, earning it the L129A1 designation and entered service April 2010 in Afghanistan.[13]

Greg Felton of Law Enforcement International of the UK explained: “The ammunition criteria stated by the MOD was that the rifle was to be able to use both RG 155-grain sniper ammunition, plus M80 ball and tracer, including de-linked machine gun belts. In the end during their trials with the various competitors, they found that the 155-grain fired so much better than the standard ball that it was made the official issue ammunition for the weapon. As to what it is “matched to,” we (Karl & I) designed the rifle to use both standard ball and 168-grain Match. With a 1:11.25 inch twist it works well with these weights, however, the heavier 175-grain projectiles need a faster twist for best results at longer ranges.”[13]

The primary optic chosen by the British for the L129A1 is a Trijicon ACOG TA648-RMR-UKS (NSN: 1005-99-305-9104).[13] The ACOG’s body is made of 7075 T6 aircraft aluminium, the same as the rifle’s receiver. A fiber-optic powers the reticle during daylight hours and a tritium light source in low or no light conditions. The aiming chevron’s brightness is adjustable by the user. The unit’s reticle has a built-in bullet drop compensator for 7.62×51mm NATO from 100 to 1,200 meters. To transition from long range to close-quarter battle, there is a Picatinny rail on the ACOG’s top that accepts a 1.2-ounce Trijicon 1× LED Rugged Miniature Reflex sight with a red dot powered by a CR2032 battery. Additional accessories include the optional L17A2 Schmidt & Bender 3-12 × 50 Sniper Scope, the OTIS 7.62mm Sniper Cleaning System, a small Dewey rod[14] to clean the chamber, a front sight adjustment tool and a rail-mounted, quick-detachable sling mount so the sling may be mounted anywhere on the rail.

The LM308MWS standard US commercial model differs slightly from the UK issued L129A1 in the following aspects:

  • 1) the barrel is a 16" fully chrome-lined, cryogenically treated, polygonal rifled 1:10 right-hand twist chrome-moly machine gun grade steel, instead of the 16", 1:11¼" twist matte-black stainless steel barrel on the L129A1. It is crowned with LMT's special crown design, designed for maximum accuracy with ordinary ball ammunition.
  • 2) the muzzle device is a standard M16A2 type flash suppressor instead of the SureFire suppressor mount.
  • 3) the sights are the LMT detachable fixed sights instead of the Knight's Armament Company's low-profile folding micro back-up iron 200-600 rear sight and folding front sight.
  • 4) the supplied furniture—LMT SOPMOD stock, Ergo suregrip, rail covers from Tango Down—is black instead of the tan/coyote brown supplied to the UK MoD.
  • 5) the receiver is marked "LM308MWS", instead of "L129A1."

There are also UK commercial variants of the L129A1 and the CQB MRP Defender. Designated the LMT308SP and CQB 5.56SP the modelS are a straight pull action rifle, and not a semi-auto due to UK laws.[15]

The New Zealand Army adopted the rifle in October 2011. It differs from its UK counterpart in the use of a Leupold adjustable 4.5-14× scope, canted iron sights and a foldable foregrip.


The LMT® Modular Ambidextrous Rifle System (MARS®) - Light (MARS-L)
TypeAssault rifle
Place of originUnited States
Service history
In service2015-Present
Used by
Production history
ManufacturerLewis Machine & Tool
Mass3.3kg (empty)
  • 914 mm (36.0 in)

Cartridge5.56×45mm NATO
Feed system5.56×45mm NATO: 30-round detachable box magazine

New ZealandEdit

On 12 August 2015, the New Zealand Ministry of Defence announced that it would be replacing the current Steyr AUG 5.56×45mm rifle for all branches of the New Zealand Defence Force with a product from LMT,[16] later revealed to be their CQB16 version of the AR-15. A tender was released from May to November 2014. LMT was one of eight companies that submitted rifles for trials that took place between March and June 2015. Two versions with 406 mm (16.0 in) and 457 mm (18.0 in) barrels were delivered, firing heavy 77 gr (5.0 g) ammunition. With the selection of the CQB16, the NZDF switched from fielding a Steyr AUG bullpup rifle to one with a traditional layout, as well as a semi-direct gas impingement operating system over a gas-piston system likely offered by competing entrants.

The NZD $59 million contract was for 9,040 rifles to equip all three branches of the New Zealand Defence Force. The rifle was designated by the Defence Force as the MARS-L (Modular Ambidextrous Rifle System-Light).[17][18]

The weapons were delivered in May 2017, and soldiers of 1RNZIR were the first to begin training with it at Waiouru Military Camp on 15 June 2017.[19]

In September 2018 it was reported that some of the rifles had experienced breakages, including 130 with cracks around the bolt, and that all 9,040 rifles had had their firing pins replaced under warranty.[20] LMT later responded that some of the facts about the problems were misreported. They claimed that the number of worn or broken firing pins was actually much smaller, in the range of "less than one tenth of one percent". The issue reportedly stemmed from improper tempering. As a precaution, they had decided to replace the firing pins on all the rifles. While replacing the firing pins, they had also discovered that a similar quantity of selector switches and bolt carriers displayed premature wear, and promptly replaced those parts as well.[21]


In May of 2019, the Estonian Defence Forces selected the MARS-L after two years of testing to replace their IMI Galil and Ak 4 rifles. 16,000 MARS-L rifles were ordered under the designation R-20 Rahe which means 'hail' in Estonian. The first batch of 1,500 rifles was delivered in June of 2020. The R20 is planned to fully replace the Galil and Ak 4 by 2022.[citation needed] The R20 features a monolithic M-LOK upper receiver and LMT's short-stroke gas piston system. The R-20 is being produced in two configurations: a 14.5" (368mm) barreled variant and a 12.5" (318mm) barreled variant.[22]

7.62x51mm NATO variant with a 16" (411mm) barrel designated as R-20 L is used as a designated marksman rifle.

Enhanced bolt carrier groupEdit

Enhanced boltEdit

Lewis Machine and Tool has been improving components of the AR/M16-M4 family of weapon systems since 1980. One of these improved components is the bolt of the Direct Impingement operating system. A patented design made from a proprietary material, the enhanced bolt features a double spring "lobster tail" extractor for more positive extraction in adverse conditions. Improved bolt lug design and a low maintenance coating adds to the performance and reliability of the LMT Enhanced Bolt.

Enhanced bolt carrierEdit

LMT Defense improved the standard full auto and semi auto bolt carrier for the AR as well. This enhanced carrier comes with numerous improvements, one of which is the elongated travel of the bolt cam pin. This elongated cam travel path allows the bolt to stay locked in battery for a longer time thus increasing its efficiency within the direct impingement system and allow the case to properly complete its cycle after being fired improving ejection and extraction reliability. Another noteworthy improvement the enhanced carrier brings to the weapon system is the additional gas venting holes. These additional holes allow gasses used in the cycle operation to quickly be vented from the carrier once the bolt is in motion. Additional gas venting holes also reduce over pressure of the system when utilizing a suppressor on the weapon. This is typically used on 14.5" and 16" barrels with a carbine gas system. Some users may experience failures when using this carrier on an unsuppressed short barrel rifle like a 10.5" carbine. Further features of the enhanced carrier include reduced contact rails for better lubricity and debris avoidance, and the gas inlet diversion ports which distribute the incoming gas in a more even pattern.


  1. ^ "Lewis Machine & Tool Company". Archived from the original on 25 December 2014. Retrieved 25 December 2014.
  2. ^ The National-Military Muscle on Display
  3. ^ "Lewis Machine & Tool Monolithic Rail Platform". Retrieved 25 December 2014.
  4. ^ Grassi, Rich (9 May 2009). "LMT CQB MRP Defender 5.56mm". Tactical Life. Retrieved 31 May 2017.
  5. ^ LMT’s MRP 6.8 Battle Rifle
  6. ^ "Multi-Mission LMT .308 MWS". Tactical Life. 3 November 2009. Retrieved 25 December 2014.
  7. ^ "CQB 10.5 SBR". Lewis Machine & Tool Company. Retrieved 31 May 2017.
  8. ^ "Firearms used by British Transport Police - Freedom of Information Request 794-14" (PDF). British Transport Police. Retrieved 31 May 2017.
  9. ^ Austin, Jon (17 October 2015). "Guns on the Underground: Armed police to routinely patrol Tube amid threat from ISIS". Express. Home of the Daily and Sunday Express. Retrieved 31 May 2017.
  10. ^ "Global Defence News and Defence Headlines - IHS Jane's 360". Retrieved 25 December 2014.
  11. ^ "L129A1 sharpshooter rifle". Retrieved 25 December 2014.
  12. ^ "LMT .308 AR Review". Guns & Ammo. Retrieved 25 December 2014.
  13. ^ a b c Sharpshooter: The UK’s New L129A1 7.62x51mm Rifle - SAdefensejournal.com, 11 January 2012
  14. ^ J Dewey Rods, Field Kit, AR .308 / 7.62, DFK-AR10
  15. ^ "Lewis Machine & Tool Company, Inc. LM308SP-SS20 .308 Rifles". Retrieved 29 December 2015.
  16. ^ "Individual Weapon Replacement". defence.govt.nz. 12 August 2015. Archived from the original on 18 August 2015.
  17. ^ New Zealand Army Selects LMT To Replace Steyr AUG - Thefirearmblog.com, 18 August 2015
  18. ^ Confirmed, LMT to supply NZDF with CQB16 - Thefirearmblog.com, 28 August 2015
  19. ^ New $59 million weapons package begins Defence Force rollout -Stuff.co.nz, 16 June 2017
  20. ^ David.Fisher@Nzherald.Co.Nz, David Fisher Senior Writer (19 September 2018). "NZDF's new rifles - all 9040 of them - get firing pin replacements after breakages". NZ Herald.
  21. ^ "LMT Warranties Components with New Zealand Defense Forces MARS-L". The Firearm Blog. 25 September 2018.
  22. ^ https://www.thefirearmblog.com/blog/2019/05/17/lmt-defense-announces-award-with-estonian-defence-forces/

External linksEdit