LMT MWS (MARS-H)
Lewis Machine & Tool · Sniper Rifle · In Production · 2009
Also known as: L129A1, LMT Sharpshooter, MARS-H DMR, LMT MWS DMR, Lewis Machine & Tool MWS
Overview
The LMT MWS (Modular Weapon System), marketed commercially as the MARS-H (Modular Ambidextrous Rifle System - Heavy), is a semi-automatic precision rifle chambered in 7.62x51mm NATO built around LMT's patented Monolithic Rail Platform (MRP). The MRP upper receiver is machined from a single aerospace-grade aluminum forging, integrating the rail system and barrel mounting interface into one rigid structure that delivers exceptional accuracy and repeatability when swapping barrels. The DMR variant features a 508mm (20-inch) stainless steel 5R-cut barrel with 1:11.25-inch twist rate optimized for heavy match bullets. Fully ambidextrous controls, direct impingement gas system, and quick-change barrel capability make the MARS-H one of the most versatile and accurate semi-automatic precision platforms in military service.
Specifications
| Weight (empty) | 5897 g (208.0 oz) |
| Weight (loaded) | 6400 g (225.8 oz) |
| Overall Length | 1041 mm (40.98") |
| Barrel Length | 508 mm (20.00") |
| Action Type | Gas Operated Direct Impingement |
| Firing Mechanism | Rotating Bolt |
| Trigger Type | Two Stage |
| Magazine Capacity | 20 rounds |
| Magazine Type | Detachable Box |
| Muzzle Velocity | 780 m/s (2559 fps) |
| Muzzle Energy | 3448 J (2543 ft·lbf) |
| Effective Range | 800 m (875 yd) |
| Maximum Range | 3700 m (4046 yd) |
| Barrel Rifling | Right Hand |
| Rifling Twist | 286 mm (11.26") |
| Number of Grooves | 5 |
| Frame Material | Aluminum Alloy |
| Barrel Material | Stainless Steel |
| Stock Material | Polymer |
| Finish | Matte Black |
Calibers
- 7.62x51mm NATO · primary · 7.62x51mm NATO — also known as .308 Winchester, 7.62mm NATO, 7.62x51mm
Features
- Firing modes: Semi Automatic
- Feed systems: Detachable Box Magazine
- Safety mechanisms: Ambidextrous Safety, Firing Pin Safety
- Features: Monolithic Rail Platform, Free Floating Barrel, Match Grade Barrel, Quick Change Barrel, Picatinny Rail, Suppressor Ready, Ambidextrous Controls, 5r Rifling
Variants
- LMT MARS-H Battle Rifle — Battle Rifle
- LMT MARS-H 13.5" Barrel — Carbine
Service history
Operators
- British Armed Forces · adopted 2009 · as L129A1 Sharpshooter
- New Zealand Defence Force · adopted 2017 · as MARS-L/H
- Estonian Defence Forces
- United States Law Enforcement (various agencies)
Conflicts
- War in Afghanistan (2001-2021)
- Russo-Ukrainian War (2022-present)
Production
Production years: 2009-present
British L129A1 contract was for approximately 3,000 units. Additional military and commercial production ongoing.
Origin
Country of origin: United States
Designer: Karl Lewis
Notes
The LMT MWS gained fame when it won the British Army's L129A1 Sharpshooter contract in 2009, beating competitors including the HK417 and FN SCAR-H. The L129A1 proved so effective in Afghanistan that British troops reportedly requested additional allocations beyond initial issue. The MRP system allows barrel changes in under 60 seconds without tools beyond a torque wrench, maintaining zero when swapping between barrel lengths and calibers. New Zealand adopted the LMT platform for both 5.56mm and 7.62mm roles. The 5R rifling (5 lands with opposite-radius edges) reduces bullet deformation and copper fouling while improving accuracy.
Background
When British soldiers first deployed with the L129A1 in Afghanistan, the rifle filled a critical capability gap between the 5.56mm SA80 and the bolt-action L115A3 sniper rifle. Troops in Helmand Province found the semi-automatic 7.62mm platform so effective at intermediate ranges that demand quickly outstripped supply, with units competing for additional allocations of the 'Sharpshooter' rifle.