Bolt and bolt carrier groups

Lewis Machine and Tool Company produces a patented AR-15-pattern 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 performance of the rifle's “internal piston” system gas operation.

LM308MWS and CQB MRP Defender

Lewis Machine and Tool Company created the Monolithic Rail Platform (MRP),^[2] a one-piece, Picatinny-topped AR-15-pattern upper receiver made from a forged aluminum block.^[3] The MRP upper receiver has a quick-change barrel system.^[4] Its top rail position matches M4 and E3-type weapons for optical and sight compatibility.^[5]

In late 2009, LMT introduced the .308 Modular Weapon System LM308MWS, which uses the 7.62×51mm NATO round.^[6]

In February 2012, the British Transport Police began to use AR-pattern short-barreled rifles produced by LMT.^[7][8][9]

L129A1

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] Its NATO Stock Number (NSN) is 1005-99-226-6708. As of December 2014, over 3,000 units have been supplied to UK forces.^[12]

During the war in Afghanistan British light infantry units sometimes found themselves outranged by small arms beyond the effective range of their assault rifles and light machine guns chambered for the intermediate 5.56 mm NATO cartridge. At ranges between 400 and 800 m (437 and 875 yd), the then available small arms capable of returning effective fire, were the general-purpose machine gun and the bolt-action sniper rifle. These weapons chambered for the fully-powered 7.62 mm NATO cartridge were not well suited to increase the effective engagement range of the British eight-man rifle sections.

The LM308MWS was submitted for the British Ministry of Defence's Urgent Operational Requirement (UOR) for immediate deployment of a semi-automatic 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 entering service in April 2010 in Afghanistan. One member (termed the "sharpshooter") of the British rifle sections, was issued an L129A1 instead of an assault rifle. The standard optic for the L129A1 is the TA648-308 6×48 Trijicon ACOG providing a 8 mm exit pupil for ample light gathering and a wide field of view. 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 within minutes with a return to zero of the same barrel. It features an 11.25 in (285.8 mm) twist rate to fire standard 144-grain 7.62 mm ball up to 168-grain BTHP ammunition used by NATO, but the official issue rounds are 155-grain L42A1-A3 sniper and L59A1 "High Performance" ball ammunition.^[13][14][15] The ACOG is mounted to a Picatinny rail to which is fitted a Trijicon RM01 1 x Ruggedized Miniature Reflex (RMR) for Close Quarters Battle use.

L129A1 Sniper Support Weapon (SSW) version fitted with a 3-12×50 telescopic sight

A Sniper Support Weapon (SSW) version, also designated L129A1, was adopted for use by the second man in each sniper team and is fitted with a Schmidt & Bender 3-12×50 telescopic sight and a Surefire suppressor.^[16][17]

LMT 308 MWS used by the New Zealand Army

The New Zealand Army adopted the rifle under the LMT 308 MWS designation in October 2011. It differs from its UK counterpart in being select fire instead of semi=automatic only, a 20 in (508 mm) barrel the use of a Leupold adjustable 4.5-14× telescopic sight, canted iron sights and a foldable foregrip.

Within the Royal Marines at least, an improved Modular Ambidextrous Rifle System (MARS-H) based L129A2 version chambered in 6.5 mm Creedmoor with an 18 in (457 mm) barrel, a new Leupold scope, a HuxWrx suppressor, an Envision Technology ballistic calculator, and a Pixels-on-Target thermal sight was adopted in 2023.^[18][19]

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.^[20] 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).^[21][22]

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.^[23]

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.^[24] LMT later 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".^[25] 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.^[25]

Estonia

Estonian R-20 L 7.62×51mm NATO designated marksman rifle

In May 2019, the Estonian Defence Forces selected the MARS-L after two years of testing to replace their IMI Galil and Ak 4 rifles. 19,000 short-stroke piston MARS-L rifles were ordered under the designation R-20 Rahe ("Hail" in Estonian).^[26] 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.^[27][28] 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.^[29] 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 diagnostic maintenance warnings.^[30]

In June 2020, the first batch of 1,500 R-20 Rahe rifles was delivered.^[31] The R-20 is planned to fully replace the Galil and Ak 4 by 2022.^[32]

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.^[33]

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.^[34] 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.^[35][36]

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.^[37] 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).^[38][39] 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.^[40] The upper receiver still uses a gas-operated, rotating bolt (internal piston) system like the L129A1, but the hand guard attachment points on its sides were changed to be M-LOK compatible.^[41][42]

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 were offered on the internet in late 2023.^[43]