# Lewis Machine & Tool Company

Lewis Machine & Tool Company (LMT) is an American armaments company founded by Karl Lewis, in 1980. It manufactures weapon systems, including a variant of the M4 carbine and the M203 grenade launcher. Its products are used by the military forces of the United Kingdom, New Zealand, Estonia, Switzerland, Lebanon and the United States. It formerly produced forged FN FAL receivers for Illinois-based DS Arms.

## Products
### Bolt and bolt carrier groups

A patented AR-15-pattern is produced with a bolt design featuring a redesigned extractor intended to improve the extraction of cartridges under adverse conditions. The company also produces a redesigned bolt carrier intended to improve the reliable performance of the rifle's “internal piston” system by obtaining a similar timing sequence with 14.5-inch carbine-length barrels compared to 20-inch rifle-length barrels for AR-15-pattern arms.

### LM308MWS and CQB MRP Defender

The Monolithic Rail Platform (MRP) was created by the company, a one-piece, Picatinny-topped AR-15-pattern upper receiver made from a forged aluminum block. The MRP upper receiver has a quick-change barrel system. Its top rail position matches M4 and E3-type weapons for optical and sight compatibility.
In late 2009, LMT introduced the .308 Modular Weapon System LM308MWS, which uses the 7.62×51mm NATO round.
In February 2012, the British Transport Police began to use AR-pattern short-barreled rifles produced by LMT.

### L129A1
## Modular Ambidextrous Rifle System

The Modular Weapons System (MWS) was developed into the Modular Ambidextrous Rifle System (MARS), available in light and heavy variants. The light assault rifle variants are chambered for the 5.56×45mm NATO intermediate cartridge and the heavy battle rifle/designated marksman rifle variants for the 7.62×51mm NATO, 6.5 mm Creedmoor or similar fully powered cartridges. MARS weapons feature lower receivers updated to fully ambidextrous mirrored controls and can be set up to use gas-operated, rotating bolt (internal piston, not direct impingement) or short-stroke piston operating systems with the help of basic tools. The MARS receiver can host and switch between barrels of varying length, and diameter. material, and caliber. Two locking bolts accessible from the right side of the receiver with a basic tool lock a barrel extension and make the barrel unit user removable with a return to zero of the same barrel. MARS series weapons were sold to several military users.

### New Zealand

On 12 August 2015, the New Zealand Ministry of Defence announced that it would be replacing the current Steyr AUG rifle for the three branches of the New Zealand Defence Force with a rifle from LMT, one of eight companies that had submitted rifles for trials between March and June 2015. Like the Steyr AUG, the submitted LMT design was also chambered in 5.56×45mm NATO. A contract of NZD 59 million was awarded to LMT for 9,040 rifles, designated the MARS-L (Modular Ambidextrous Rifle System-Light).
The gas-operated, rotating bolt (internal piston) rifles were delivered in May 2017, and soldiers began training with them at Waiouru Military Camp on 15 June 2017.
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. LMT later claimed that the number of worn or broken firing pins was much smaller, in the range of "less than one-tenth of one percent". The issue reportedly stemmed from improper tempering. While replacing the firing pins, a similar quantity of selector switches and bolt carriers had also been found to display premature wear and were replaced.

#### Civilian variant

For civilian customers, LMT offers a semi-automatic only New Zealand Reference Rifle in its model range.

### Estonia

In May 2019, the Estonian Defence Forces selected the MARS-L after two years of testing to replace their IMI Galil and Automatkarbin 4 rifles. The Estonian Defence League Started using the R-20 in early 2023. 19,000 short-stroke piston MARS-L rifles were ordered under the designation R-20 Rahe ("Hail" in Estonian). The upper receiver has a Picatinny rail on the top and M-LOK compatible attachment points on its sides and uses a short-stroke gas piston system. The standard barrel length of the R-20 is 14.3 in (363 mm), but a 12 in (305 mm) variant designated the R-20 S is also produced. A modified trigger design allows the trigger safety to be engaged without the hammer being cocked, which is not possible on a standard AR-15 pattern rifle. The rifles were ordered with a Shot Counter Grip Module housed within the pistol grip to track parts wear and ammunition consumption with objective digital data. The accompanying reader unit can provide armorers with diagnostic maintenance warnings.
In June 2020, the first batch of 1,500 R-20 Rahe rifles was delivered. The R-20 is planned to fully replace the Galil and Ak 4 by 2022.
Estonia also selected the MARS-H with a 16 in (406 mm) barrel as their designated marksman rifle chambered in 7.62×51mm NATO. The official Estonian designation for the MARS-H marksman rifle is the R-20 L.

#### Civilian variant

For civilian customers LMT offers the a semi-automatic only Estonia R20 RAHE Reference Rifle in its model range.

### Switzerland

A 7.62mm Zf Stgw 20 designated MARS-H based designated marksman rifle chambered in 7.62×51mm NATO was introduced in 2023 by the Swiss Army Reconnaissance Detachment 10 and MP Spez Det. These Swiss (professional) special forces units selected the Schmidt & Bender 3-20×50 PM II Ultra Short telescopic sight with the TREMOR3 reticle that enables quick targeting up to 800 m (875 yd) as their standard aiming optic.
After Swiss trails, Stgw 25 (16 in (406 mm) barreled) and Stgw 25K (12 in (305 mm) barreled) designated short-stroke piston MARS-L based assault rifles chambered in 5.56×45mm NATO, were selected for purchase during 2025 as an additional weapon system for certain Swiss Armed Forces units.
As of March 2025, LMT does not offer any semi-automatic only Swiss Armed Forces MARS based Reference Rifle model for civilian customers in its model range.

### United Kingdom

Within the Royal Marines at least, a MARS-H based L129A2 designated marksman rifle chambered in 6.5 mm Creedmoor with an 18 in (457 mm) barrel, a fully adjustable DMR stock and lengthened hand guard, a Leupold Mark 5HD 3.6-18×44 M5C3 Desert IR telescopic sight with TREMOR3 reticle, a HuxWrx suppressor, an Envision Technology ballistic calculator, and a Pixels-on-Target thermal sight was adopted in 2023. The change from 7.62×51mm NATO ammunition to 6.5 Creedmoor was due to the 6.5 Creedmoor's better ability to successfully engage targets at distances around and over 800 m (875 yd). The main disadvantages of this change are introducing a new chambering in the logistics chain, and due to a higher O$_{ratio}$ is shortened barrel life. The upper receiver still uses a gas-operated, rotating bolt (internal piston) system like the L129A1, but the handguard attachment points on its sides were changed to be M-LOK compatible.

## Other contractors
### Lebanon

An undisclosed amount of Short Barreled Rifles (SBR) chambered for the 5.56×45mm NATO intermediate cartridge with an 10.5 in (267 mm) barrel have been ordered by Lebanon. The existence of a Lebanese contract became apparent as a production overrun of these weapons was offered on the internet in late 2023.